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  • Artikel  (209)
  • Artikel: DFG Deutsche Nationallizenzen  (209)
  • Solanum tuberosum L.  (104)
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  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical crystallography 24 (1994), S. 759-762 
    ISSN: 1572-8854
    Schlagwort(e): Sulfonamide ; methanesulfonanilide ; crystal structure ; molecular structure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The title compound, crystallizes in the triclinic space group $$P\bar 1$$ witha=8.232(4),b=9.159(2),c=10.230(3)Å. α=74.07(3)°, β=72.50(4)°, γ=63.65(3)° andZ=2. The structure was solved by direct methods and refined by full matrix least squares methods toR=0.054 for 1817 observed reflections. The plane containing the nitrogen and sulfur atoms is perpendicular to the aromatic plane. One of the S−O bonds in each methanesulfonyl group is in nearly eclipsed conformation with the N−C bond.
    Materialart: Digitale Medien
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical crystallography 24 (1994), S. 437-440 
    ISSN: 1572-8854
    Schlagwort(e): Ca(C4H4O4)·H2O ; pentagonal pyramid ; calcium succinate ; crystal structure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The crystal structure of calcium succinate monohydrate, Ca(C4H4O4)·H2O, has been determined by single crystal X-ray diffraction. The crystals are monoclinic witha=11.952(2),b=9.691(2),c=11.606(2)Å, β=108.81(1)°, space group C2/c,Z=8,V=1272.49 Å3,d m =1.80, andd c =1.818 Mg m−3. The structure was refined by full-matrix least-squares techniques toR=0.027,R w =0.040, for 829 reflections with1≥3δ(I). Ca is coordinated to seven oxygen atoms, and the coordination polyhedron is best described as a pentagonal bipyramid. One carboxylate group in the succinate ion is bonded to three different Ca ions, forming a four-membered chelate ring with one Ca ion is bonded to three different Ca ions, forming a four-membered chelate ring with one Ca ion and unidentate bridge bonds to two other Ca ions. The other carboxylate group is bonded to two Ca ions through unidentate bonds. The structure is highly polymeric. The general structural features are nearly identical to those of calcium adipate monohydrate.
    Materialart: Digitale Medien
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical crystallography 24 (1994), S. 731-737 
    ISSN: 1572-8854
    Schlagwort(e): Synthesis ; crystal structure ; IR data
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The synthesis, crystal structure and IR data are reported for Na2[Zn(CMA)4]·2EtOH·7H2O, where CMA− is the 9,10-dihydro-9-oxo-10-acridinacetate ion. The complex crystallizes in the monoclinic space group P2/n, with cell dimensionsa=17.335(9),b=8.440(5),c=21.875(12) Å, β=91.94(5)°,Z=2. The structure was solved by direct methods and refined to a finalR value of 0.0363 for 3022 non-zero reflections. The Zn2+ ion occupies twofold axis and is coordinated to four carboxylate ligands, the ZnO4 tetrahedron is considerably distorted with Zn−O distances of 1.978(3) and 1.961(3)Å. Each Na+ cation interacts with two water, one ethanol, and three carboxylate O atoms comprising distorted octahedron. The Zn2+ and Na+ cations are linked through monooxygen and syn-syn carboxylate bridges forming a trinuclear, mixed-metal cluster. The Zn...Na separation is 3.267(2)Å and Na...Na distance equals 3.520(2)Å. All oxygen bonded H-atoms are utilized in hydrogen bonds. The acridone rings overlap in the crystal with the 3.5 Å interlayer separations. The compound has been characterized by IR spectroscopy.
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  • 4
    ISSN: 1572-8854
    Schlagwort(e): Pyrimidine ; uracil ; crystal structure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract A new and easy method for the preparation of 1,3,7,9-tetramethylpyrido-[2,3-d∶6,5-d′]-dipyrimidine-2,4,6,8-tetrone is described. The structure of this compound has been solved by means of X-ray diffraction methods. The chemical characterization by spectral (mass, ultraviolet, infrared, and proton nuclear magnetic resonance) and thermal (thermogravimetry and differential scanning calorimetry) method is also reported. The compound is monoclinic, space groupP21/c,a=12.720(5),b=13.688(7),c=8.079(2) Å, β=107.06(4)°,Z=4. The structure consists of discrete tricyclic molecules, stacking playing an important role in crystal packing.
    Materialart: Digitale Medien
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  • 5
    ISSN: 1572-8854
    Schlagwort(e): Centrosymmetric ; symmetry ; crystal structure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The title compound crystallizes in the centrosymmetric triclinic space group $$P\bar 1$$ (C 1 l ; No.2) witha=9.9143(10) Å,b=10.2616(11) Å,c=10.7715(10) Å, α=113.887(8)°, β=109.197(8)°, γ=90.699(9)°,V=932.78(17) Å3 andZ=1. A total of 4869 data were collected and merged to a set of 2450 independent reflections; the structure was solved and refined toR=1.42% andwR=1.94%. The molecule lies on a site of $$\bar 1$$ symmetry and is disordered, with obvious scrambling of carbonyl and chloride ligands. Resulting bond lengths include Ir−P=2.339(1) Å, Ir−Cl=2.398(4) Å and Ir−CO=1.808(15) Å.
    Materialart: Digitale Medien
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  • 6
    ISSN: 1572-882X
    Schlagwort(e): cellulose I ; molecular mechanics ; crystal structure ; molecular ; modelling
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Abstract Energies for various trial packing arrangements of unit cells for the Iα and Iβ phases of native cellulose discovered by Sugiyamaet al. were evaluated. Both a rigid-ring method, PLMR, and the full-optimization, molecular mechanics program, MM3(90), were used. For both phases the models that had the lowest PLMR energy also had the lowest MM3 energy. Both calculated models have the chains packed ‘up’, O6s intg positions, and the same sheets of hydrogen-bonded chains. The Iβ structure model is essentially identical to that proposed previously for ramie cellulose by Woodcock and Sarko. It is also the same as the best parallel model previously proposed that was based on the X-ray data of Mann, Gonzalez and Wellard, once the various unit cell conventions are considered. Also, the energies from both methods for all three celluloses, Iα, Iβ and II, are in the order that rationalizes their relative stabilites.
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Potato research 37 (1994), S. 129-134 
    ISSN: 1871-4528
    Schlagwort(e): Fusarium oxysporum f.sp.tuberosi ; Solanum tuberosum L. ; dry rot ; pathogenicity ; wilt
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary A study was carried out on eightF. oxysporum f.sp.tuberosi isolates from northern Italy. Six were from rotten tubers and two were from weak, but not wilted plants from seed-growing areas. Greenhouse and laboratory tests were done to assess the pathogenicity and potential spread of the fungus within the plant. All isolates caused dry rot on inoculated tubers. They were also able to infect vascular tissues through roots and leaves, but none caused wilt, stemend rot or other symptoms.F. oxysporum is often not visible in the field, but its propagules can increase under favourable conditions. It may therefore become a potential danger during potato storage.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Potato research 37 (1994), S. 365-371 
    ISSN: 1871-4528
    Schlagwort(e): Solanum tuberosum L. ; multiplication ; micropropagation ; growth ; leaf removal ; tissue culture variation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Removing the leaves from single node potato cuttings in vitro allows propagules to be placed in culture vessels at increased densities with the intent of saving resources and space. Under light intensities of 22 wattsm−2, the removal of the subtending leaf resulted in fewer nodes, shorter plantlets, smaller leaf area, and lower fresh and dry weights of 4-week-old plantlets of cvs Atlantic, Kennebec, Russet Burbank and Shepody. Fewer nodes and reduced plantlet height may result in inefficient multiplication protocols because fewer propagules are available and shorter internodes make dissection more difficult. The coefficient of variation for the various growth parameters was greater when propagules lacked leaves, indicating that the variability of the plant material for propagation was increased. A reduction of vigour and growth was still evident when plantlets of cv. Shepody were grown for 6–8 weeks.
    Materialart: Digitale Medien
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  • 9
    Digitale Medien
    Digitale Medien
    Springer
    Potato research 37 (1994), S. 87-97 
    ISSN: 1871-4528
    Schlagwort(e): Solanum tuberosum L. ; fracturability ; column chromatography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Potato cultivars Chieftain and Kennebec were prewarmed at 70°C for 15 min. prior to heating at 100°C for 18 min. in a water bath. Chieftain exhibited a large increase in fracturability upon treatment while Kennebec showed a smaller increase. Pectic substances of the two cultivars were sequentially extracted in water, sodium hexametaphosphate (0.5%), hydrochloric acid (0.05M, 50°C), and sodium hydroxide (0.05M, 5°C). The largest fraction isolated from both cultivars consisted of hydroxide-soluble pectic substances, and was followed by the acid-soluble fraction. Chieftain contained significantly greater amounts of the hydroxide-soluble fraction than Kennebec. Ion exchange chromatography revealed that the extracted pectic substances from the two major fractions consisted of a charged pectin chain with attached neutral sugars. Gel filtration chromatography revealed wide molecular size distributions for the isolated pectic substances. Pectic neutral sugar content for the hydroxide-soluble fraction (50% of total pectic substances) was greater for Chieftain than for Kennebec.
    Materialart: Digitale Medien
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  • 10
    ISSN: 1871-4528
    Schlagwort(e): aging ; apyrase ; ATP ; bioluminescence ; bioenergetic metabolism ; luciferase ; luciferin ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary A method for determining ATP content based on sulfuric acid extraction and luciferin-luciferase bioluminescence assay was developed for potato tubers. The inactivation of apyrase by a thermal treatment as well as the ATP stability in acidic potato extracts stored at-25°C have been particularly considered. The proposed method is simple, reliable, sensitive and can be used for automatic purposes. This method has been applied to the study of the variation of ATP levels in stored potato tubers (cvs Ukama and Granola). The large changes occurring over a 9 month period are discussed in correlation with dormancy, sprouting and tuberization.
    Materialart: Digitale Medien
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  • 11
    Digitale Medien
    Digitale Medien
    Springer
    Potato research 37 (1994), S. 173-181 
    ISSN: 1871-4528
    Schlagwort(e): inbreeding ; unreduced gametes ; breeding ; yield ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Comparisons were made between tetraploid progenies obtained by crossing dihaploid and chromosome doubled dihaploid potatoes with tetraploids. Dihaploids obtained from a doubled dihaploid produced some progenies from 2xx4x crosses which were as high yielding and had as good tuber characteristics as control progenies produced by intercrossing heterozygous tetraploids. It was found that there was a slight reduction in tuber yield associated with inbreeding but selection could be made among highly inbred material for useful parents. Other characters were little affected by inbreeding. It was concluded that haploidisation and chromosome doubling could be used to produce homozygous clones for use by breeders without greatly depressing the agronomic value of their offspring.
    Materialart: Digitale Medien
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  • 12
    Digitale Medien
    Digitale Medien
    Springer
    Potato research 37 (1994), S. 217-224 
    ISSN: 1871-4528
    Schlagwort(e): Solanum tuberosum L. ; potato leafroll luteo virus ; resistance ; restricted virus multiplication ; potato breeding
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary The diploid clone DW.84-1457 which has outstanding resistance to potato leafroll virus (PLRV), has been selected at the Mlochów Centre of the Institute for Potato Research. It has in its pedigree PLRV-resistant clones from the Max Planck Institute nos. MPI 44.1016/10, MPI 44.335/130 and MPI 49.540/2. Its behaviour in the field and response to aphid inoculation indicate high resistance to infection, and the low concentration of the virus in graft-inoculated plants indicates high resistance to multiplication. This combination within one genotype of two aspects of resistance is not connected with hypersensitivity, and is heritable. Clone DW.84-1457 has other desirable characters such as extreme resistance to potato virus X (PVX), high resistance to potato virus M (PVM) and good table and processing quality. It is being utilized in the development of parental lines, both at the diploid and tetraploid level.
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  • 13
    ISSN: 1871-4528
    Schlagwort(e): fructose ; glucose ; sucrose ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary In eight experiments in 4 years, inoculating seed tubers withR. solani caused stem canker and in seven experiments decreased the total yield and the yield of tubers 40–70 mm. Yields of larger tubers were usually increased. In most experiments inoculating increased the reducing sugar content of the tubers and darkened the colour of crisps, but did not consistently affect the amounts of sucrose. Treating soil with aldicarb or oxamyl before planting also slightly increased the total reducing sugars.
    Materialart: Digitale Medien
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  • 14
    ISSN: 1871-4528
    Schlagwort(e): physiological ageing ; premature tuberization ; Solanum tuberosum L. ; transplanting shock
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Ware potatoes were produced from true potato seed by transplanting seedlings to the field in different growing periods to evaluate environmental constraints of this production method in the Nile delta. In the autumn season, with high temperatures and long-day conditions during seedling culture in the nursery and transplant establishment in the field, seedling development was fast, and transplants resumed growth within 5 days of transplanting in the field. Tuber yields ranged between 120 and 160 dt ha−1. In the spring season, with low temperatures and short-day conditions during the initial growing phase, seedling development in the nursery was slow and biomass partitioning between above ground organs (stems, leaves) and tubers was shifted towards the tubers. This partitioning was further enhanced by transplanting the seedlings in the field. Seedlings recovered only slowly from transplanting or died. It is concluded that potato production via transplants is poor in the spring season when premature tuberization of seedlings in the nursery leads to slow field establishment and low tuber yield.
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  • 15
    ISSN: 1871-4528
    Schlagwort(e): blackleg ; potato cultivars ; blanking ; cut seed tubers ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary The effect on the development of blackleg symptoms and on yield of inoculating seed tubers of 15 cultivars withErwinia carotovora subsp.atroseptica (Eca) was investigated. Tubers were planted either whole or as pieces. Eca inoculation reduced the mean yield per plant by 8% for whole tubers and by 12% for cut tubers. There was no correlation between blackleg symptoms and yield loss.
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  • 16
    ISSN: 1871-4528
    Schlagwort(e): blackleg ; cultivar ; inoculation ; Solanum tuberosum L. ; seed tuber decay ; tuber yield
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Seed potatoes of cvs Record and Bintje were grown with 30, 80 or 130 kg N/ha. In the subsequent growing season the seed tubers, which were inoculated or not with two concentrations ofErwinia carotovora subsp.atroseptica (Eca), were subjected to the same fertilization treatment. The incidence of blackleg and the level of seed tuber decay increased from the uninoculated treatment to the higher inoculum level, but the degree varied considerably from one year to another. Cv. Bintje was more susceptible to blackleg and yield loss caused by Eca than cv. Record. In 1990, when disease incidence was high, the proportion of blackleg stems increased with increasing doses of nitrogen fertilizer which had been applied to the seed crop, but was not significantly affected in 1988 and 1992. Seed tuber decay was retarded by the lowest nitrogen dose. The yield of the subsequent crop was not affected by the nitrogen dose applied to the seed crop.
    Materialart: Digitale Medien
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  • 17
    ISSN: 1871-4528
    Schlagwort(e): harvest date ; silver scurf ; black dot ; black scurf ; golding blotch ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Plots of potato plants were watered to field capacity one day before harvest on three dates, and tubers from watered and non-watered plots were stored at 7°C and 95% RH immediately or after curing at 15°C either at 80% or 95% RH. Watering increased the severity of silver scurf after storage when tubers were not cured. Curing at 80% RH decreased the disease and amounts were similar from watered and non-watered plants. Black dot was increased by watering whereas black scurf and golding blotch were decreased.
    Materialart: Digitale Medien
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  • 18
    ISSN: 1871-4528
    Schlagwort(e): Solanum tuberosum L. ; Alternaria solani Sor. ; inheritance
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Progenies from crosses between cultivars varying widely in resistance to early blight (Alternaria solani Sor.), were assessed for resistance as true seedlings in a glasshouse in Scotland. The resistance of a representative sample of surviving genotypes from each progeny was compared with samples of the same progenies not previously exposed to the fungus, both in the glasshouse in Scotland and in the field in Israel. The exposed population was more resistant. Resistance was identified more effectively in adult plants from tubers in the glasshouse than in true seedlings and agreement between glasshouse and field assessment was better when progenies were compared rather than individual genotypes. The mid parent and progeny mean scores of the unexposed population were correlated at both sites, thus confirming that the resistance is heritable. Selecting resistant individuals at the seedling stage is suggested as a useful tool for resistance breeding, having first chosen the best parents for crossing.
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  • 19
    ISSN: 1871-4528
    Schlagwort(e): crisps ; oxygen ; carbon dioxide ; Solanum tuberosum L. ; cv. Record
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary After three weeks curing at 10°C, potato tubers cv. Record were stored at 4°C under different controlled atmospheres (CA) for six months to study the effect on crisp fry colour, sprout growth and rotting. Combinations of low levels of CO2 (0.7–1.8%) and low levels of O2 (2.1–3.9%) gave a significantly lighter crisp colour, low sprout growth and fewer rotted tubers compared with 0.9% CO2 and 21.0% O2. Tubers stored in these conditions. showed a significantly higher weight loss and shrinkage after reconditioning. High CO2: low O2 combinations during storage completely inhibited sprout growth and caused the darkest crisp colour, but after reconditioning tubers gave the same level of sprouting and crisps as light as the other CA combinations. Furthermore these combinations, especially CO2 at 10 or 15%, increased the onset of rotting. Also our results showed that at low concentrations of CO2 (0.7–1.6%), and low O2 (2–2.4%) there was an increase in tuber rotting.
    Materialart: Digitale Medien
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  • 20
    Digitale Medien
    Digitale Medien
    Springer
    Potato research 37 (1994), S. 315-322 
    ISSN: 1871-4528
    Schlagwort(e): Solanum tuberosum L. ; seed production ; tuber size ; presprouting ; sprout length ; planting depth ; shoot: root ratio
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary The behaviour of minitubers in five weight classes, having mid-point values between 0.19 and 3.00 g, was studied during sprouting and emergence under controlled conditions. Lighter tubers took longer to produce sprouts of 2 mm, and their sprouts grew more slowly between 2 and 4 mm and 4 and 6 mm. As sprouts lengthened their rate of growth increased. The influence of tuber weight was less for heavier tubers and also decreased as the sprouts grew longer. When tubers with sprouts of the same length were planted in pots, sprouts from lighter tubers took longer to emerge. Emergence was later and differences between weight classes were larger when tubers were planted deeper (6 or 9 cm) or when they had shorter sprouts at planting (2 or 4 mm). At emergence, plants from lighter tubers had thinner stems and lower stem and root weights, but higher stem weights proportional to tuber weights and higher shoot:root ratios.
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  • 21
    ISSN: 1871-4528
    Schlagwort(e): Solanum tuberosum L. ; seed production ; emergence ; ground cover ; radiation interception ; radiation conversion ; harvest index
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Field performance of five fresh weight classes of minitubers ranging from 0.13–0.25 g to 2.00–3.99 g and conventional seed tubers was studied in a short growing season (79 or 82 days) in two years. The heavier minitubers gave a more regular emergence, faster ground cover soon after emergence, higher dry-matter yields, and higher fresh tuber yields. Radiation conversion coefficient (RCC) did not differ. Higher tuber yields resulted from more radiation intercepted due to a faster ground cover, and a higher harvest index. All minitubers produced plants with one primary stem. In one experiment when heavier minitubers had long sprouts, time to 50% emergence decreased with tuber weight, whereas dry-matter concentration of progeny tubers increased. Conventional tubers appeared superior to minitubers in all characteristics mentioned except RCC, which was similar. Differences in performance between minitubers and conventional tubers were attributed to weight and age of seed tubers, presprouting method and crop husbandry.
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  • 22
    ISSN: 1871-4528
    Schlagwort(e): Solanum tuberosum L. ; genetic variation ; progeny test
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary The tolerance of and resistance toGlobodera pallida of two potato progenies which segregated for these characteristics were assessed in pots in the glasshouse. The level of tolerance varied widely between genotypes within the progenies, with several genotypes being significantly more tolerant than the intolerant parent. The levels of resistance and tolerance in the progenies were not significantly correlated. No indications were obtained that the ranking of genotypes for tolerance is influenced by the density ofG. pallida in the soil. The results confirm that selection for tolerance in aG. pallida resistance breeding programme is useful and feasible.
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  • 23
    ISSN: 1871-4528
    Schlagwort(e): Storite ; Extratect ; imazalil ; culture tests ; chlamydospores ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Seed tubers were immersed in suspensions of thiabendazole (Storite) or thiabendazole plus imazalil (Extratect) at different concentrations and planted in a field experiment. During the following 2 years samples of the produce were planted after treatment with the same fungicide formulation used on the seed. Silver scurf on daughter tubers decreased as concentrations of fungicide increased and Extratect gave better disease control than Storite applied at the same thiabendazole concentration. Isolates ofH. solani resistant to thiabendazole were found on seed tubers 6 weeks after treatment with Storite, and also on daughter tubers after the first application of the higher rates of Storite; their incidence increased with further annual treatments. In 3 years no thiabendazole-resistant isolates were found after treatment with Extratect. Chlamydospores ofH. solani developed when sensitive isolates were subcultured onto agar containing thiabendazole. Isolates sensitive to thiabendazole were slightly more sensitive to imazalil than resistant ones.
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  • 24
    ISSN: 1871-4528
    Schlagwort(e): scale leaves ; sclerotial viability ; seed tubers ; pure culture ; hyphal rings ; tomato ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Polyscytalum pustulans spread from infected buds of seed tubers on the nodal scale leaves of elongating stems and stolons. More eyes were infected at the apical end of developing tubers than at the stolon end. Sclerotia, first found within the agar of ageing cultures, appeared to form from thickened hyphal rings within the aerial hyphae and conidiophores. As infected plants senesced, sclerotia developed within single or groups of host cells in diseased stem bases and remained viable for seven years in undisturbed soil. Sclerotia were also found after harvest in skin spots on decayed seed tubers.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 25
    ISSN: 1871-4528
    Schlagwort(e): Solanum tuberosum L. ; nitrogen fertilizer ; potato cultivars ; potato storage
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Potato tuber glycoalkaloid content was measured in response to nitrogen fertilizer rate, storage temperature, length of storage period and cultivar. Cvs Gemchip, Norchip and Russet Burbank were grown with applied nitrogen fertilizer rates of 0, 168 or 336 kg/ha and then stored at either 4.4 or 10°C. Total glycoalkaloid content was determined one month before harvest, at harvest, after three months of storage and after nine months of storage. Higher rates of nitrogen, higher storage temperature and a period of storage all resulted in significantly (P〈0.05) higher concentration of glycoalkaloids. The cv Norchip had higher glycoalkaloids than cvs Gemchip or Russet Burbank. Only the storage period had more influence than the environment (difference between years). Significant (P〈0.05) two-way interactions were detected for year x cultivar, year x nitrogen, storage period x cultivar and nitrogen x cultivar. Most interactions were due to the unique responses of cultivars.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 26
    ISSN: 1871-4528
    Schlagwort(e): blackleg ; early blight ; Verticillium wilt ; maturity ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Tubers of 17 cultivars were inoculated withErwinia carotovora subsp.atroseptica (ECA) and planted in 1986 and 1987 in the Negev in randomised plots in three blocks where eitherVerticillium dahliae orAlternaria solani were present or where both were absent. ECA reduced the yield in the control block and exacerbated the yield losses in the disease blocks, but the intensity of symptom expression did not always accord with the extent of yield loss. ECA had a greater effect on plants infected withA. solani than on those withV. dahliae. It was possible to categorise the cultivars as resistant, intermediate or susceptible with respect to ECA and early blight, but resistance toV. dahliae could not be differentiated from foliage maturity.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 27
    ISSN: 1871-4528
    Schlagwort(e): PVA ; selection ; assay reactivity ; ELISA-types ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary A panel of mouse monoclonal antibodies (MAbs) was prepared against potato virus A (PVA) and their reactivity was tested in various types of ELISA. The type of ELISA as well as the methods of MAbs purification played an essential role. All monoclonal antibodies reacted with PVA antigen in IDAS-ELISA but MAbs used in DAS1-ELISA and in DAS2-ELISA, in combination with polyclonal antibodies, showed different reactivity. The reactivity of MAbs in DAS-ELISA was dependent on the individual MAb used as a coating or as a conjugate. Two MAbs showed highest reactivity as coating antibodies but only one of them as a conjugate. The results demonstrate the importance of using different type of ELISA in selecting MAbs for routine diagnosis.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 28
    ISSN: 1871-4528
    Schlagwort(e): cell wall ; middle lamella ; cell sloughing ; apparent diffusion coefficient ; texture ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary The potato cultivars Nicola and Irene were investigated with respect to cell sloughing, specific cell surface area, release of pectic material and transfer of ions using a model cooking study. Both cell sloughing and the release of pectic material were higher for the mealy-cooking cultivar Irene. As the respective cell size distributions measured were the same for both cultivars, the difference in release of pectic material could not be explained by a difference in the specific cell surface areas between the cultivars. Additionally, it was recorded that during cooking only 20% of the calcium present in non-cooked tissue was transferred into the cooking medium, whereas more than 70% of potassium and citrate were transferred. The ratios Da.citr2−/Da.K+ and Da.Ca2+/Da.K+ for water and cooked potato tissue revealed that in water, potassium ions diffused faster than citrate and calcium ions. However, in cooked potato tissue both citrate and calcium ions diffused faster than potassium ions.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 29
    ISSN: 1871-4528
    Schlagwort(e): AMPPD ; guanidinium isothiocyanate ; plant material extraction ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary The potential use of a simple, sensitive and non-radioactive method for detecting potato spindle tuber viroid (PSTVd) in germinated true potato seeds, based on nucleic acid hybridization with a PSTVd-specific DNA probe labelled with digoxigenin, was investigated. Two simple procedures for the clarification of plant extracts suitable for a non-radioactive detection system were also investigated. The nucleic acid hybridization technique could detect one PSTVd-infected seed in more than 150 healthy seeds. The benefits of this non-radioactive detection system are discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 30
    Digitale Medien
    Digitale Medien
    Springer
    Potato research 37 (1994), S. 287-290 
    ISSN: 1871-4528
    Schlagwort(e): imazalil ; thiabendazole ; black dot ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Silver scurf on daughter tubers at harvest was decreased by treating seed tubers with imazalil or thiabendazole in March but significantly increased when the treated tubers were wounded the day before planting in May. The disease was also increased by wounding seed tubers not treated with fungicide. Black dot was decreased by seed treatment with imazalil but was not affected by wounding.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 31
    ISSN: 1871-4528
    Schlagwort(e): propagation sources ; row spacing ; canopy cover ; tuber yield ; grade distribution ; multiplication rate ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Microtuber and minitubers of cv. Monalisa were produced in the laboratory and compared with normal seed tubers in a field experiment. These tubers were planted at similar plant densities (13.6 sprouts per m2) with two distances between rows (60 and 90 cm). Final ground cover was almost complete only in the plots derived from normal tubers and decreased with the size of the mother tubers. Normal seed, mini- and microtubers yielded respectively 50.8, 31.7, and 17.0 t/ha (means of two spacings). At close and wide spacing between rows, microtubers yielded respectively 27.3 and 6.7 t/ha, and minitubers 38.9 to 24.4 t/ha. Row spacing did not influence the yields from normal seed tubers. Total number of tubers per m2 was also affected and, as means of the two spacings, ranged from 107.8 with microtubers, 122.1 with minitubers, to 142.9 with normal tubers. Mother tuber type also affected the yield distribution in three tuber grades (〈36, 36–55, and 55–80 mm) and micro and minitubers produced many small tubers. Multiplication rates and the possible use of different propagation sources are discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 32
    Digitale Medien
    Digitale Medien
    Springer
    Potato research 37 (1994), S. 423-428 
    ISSN: 1871-4528
    Schlagwort(e): In-vitro selection ; tolerance test ; tolerance constancy ; genetic instability ; selective medium ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Tests were made of the influence of selective and nonselective culture media on the rate of production of aluminium tolerant regenerant clones. Regenerants died when selective medium containg Al was continuously applied in tolerance tests. The production of aluminium tolerant clones was dependent on alternating selective and nonselective media. Tests using a medium containing 6 mmol al resulted in 50% growth as compared to control plants. Regenerants showed no growth when a medium with 10 mmol Al was applied. No constant tolerance was obtained when only a nonselective medium was used for regneration.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 33
    ISSN: 1871-4528
    Schlagwort(e): Solanum tuberosum L. ; dry matter partition ; nitrogen content ; DW/Nratio ; nitrate ; ammonium ; glutamic acid ; in vitro nitrogen source
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Different nitrogen sources (NO3 −, NH4 +, glutamic acid and their combinations) influenced the growth and morphogenic responses (node number, shoot length, and stem, leaf and root dry weight) of three micropropagated potato cultivars (Spunta, Kennebec, Huinkul). Addition of reduced nitrogen (NH4 + or glutamic acid) in a nitrate medium increased shoot length and leaf number. The large increase in growth in plants fed with NO3 −, NH4 + could be explained by higher organic nitrogen content and enhanced dry matter partition to the shoot. This suggests that reduced nitrogen source is required, at least as a supplement to NO3 −, to enhance N assimilation and growth.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 34
    Digitale Medien
    Digitale Medien
    Springer
    European journal of plant pathology 100 (1994), S. 137-156 
    ISSN: 1573-8469
    Schlagwort(e): biological control ; mycoparasite ; potato black scurf ; Rhizoctonia solani ; sclerotia ; soil
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Verticillium biguttatum cannot utilise cellulose or nitrate-nitrogen and it requires biotin for growth, yet it grew and sporulated abundantly onRhizoctonia solani on cellulose, obtaining at least organic carbon, nitrogen and biotin fromR. solani. Videomicroscopy of inter-hyphal interactions on films of water agar showed thatV. biguttatum behaved as a biotrophic mycoparasite. From germinating spores, it penetrated the hyphae ofR. solani and formed haustorium-like branches without killing the host cells, and the haustoria supported an external mycelial network of the mycoparasite. Later the mycoparasite sporulated, and the infected host cells died. On cellulosic substrataV. biguttatum did not reduce the growth ofR. solani, and often enhanced the rate of cellulose degradation. However,V. biguttatum drastically reduced the production of sclerotia byR. solani, often completely suppressing sclerotium production when the mycoparasite infected only a localized region of the host colony. This is ascribed to the creation of a nutrient sink by the parasite, consistent with biotrophy. On plates of cellulose agar the suppression of sclerotia was not confined to parasitized colonies but extended to adjacent colonies ofR. solani that had successfully anastomosed with the parasitized colony. There was no effect on adjacent vegetatively incompatible colonies, where attempted anastomoses caused cytoplasmic death. In comparable experiments the necrotrophic mycoparasiteGliocladium roseum had no long-distance effect on sclerotium production byR. solani. Suppression of sclerotium production may explain the reported success ofV. biguttatum in biocontrol of black scurf of potato in experimental field conditions.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 35
    ISSN: 1573-8469
    Schlagwort(e): biological control ; antibiotics ; Tn5 mutagenesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Pseudomonas fluorescens strain CHA0 is an effective biocontrol agent of various soilborne pathogens. It controls damping-off or root rot caused byPythium ultimum on cucumber, wheat and cress. Strain CHA0 synthesizes several antibiotic metabolites such as hydrogen cyanide, 2,4-diacetylphloroglucinol, and pyoluteorin. The role of pyoluteorin in the suppression of damping-off was investigated. Two Tn5 mutants (CHA660 and CHA661) of strain CHA0 were isolated which had lost the capacity to produce pyoluteorin but still produced 2,4-diacteylphloroglucinol and HCN. These mutants still inhibitedP. ultimum on malt agar (which favours the production of 2,4-diacetylphloroglucinol) but had partially lost the ability to inhibit this pathogen on King's B agar (which favours the production of pyoluteorin). The two pyoluteorin-negative mutants showed a reduced capacity to suppress damping-off of cress caused byP. ultimum but were as effective in the protection of cucumber against this pathogen as the wild-type strain. These results indicate that, depending on the plant, pyoluteorin production plays a role in the suppression of damping-off by strain CHA0 without being a major mechanism in disease suppression. We suggest that the contribution of pyoluteorin to the biocontrol activity of strain CHA0 is determined by the quantity of this antibiotic produced in the rhizosphere, which might depend on the root exudates of the host plant.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 36
    ISSN: 1573-5036
    Schlagwort(e): antibiosis ; bacterization ; biological control ; chitinase ; sheath blight
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Bacterial antagonists of both fluorescent and nonfluorescent groups were screened for in-vitro inhibition of the rice sheath blight (ShB) fungus Rhizoctonai solani Kuhn and chitinase production in the laboratory. Twelve percent of the total 1,757 strains screened inhibited R. solani while 31% of the total 1,366 strains tested were positive for chitinase activity. The efficient strains were then evaluated in the field for ShB suppression. Two strains from each of the three seed-bed experiments were chosen for the field test in a hot-spot location. Additional treatments were a Bacillus and validamycin, the fungicide. There was no correlation between chitinase activity in the antagonists and ShB suppression in the seed-bed or field plots. Two most efficient Pseudomonas putida and P. fluorescens strains afforded 68 and 52% ShB suppression while validamycin afforded 27% disease control.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 37
    ISSN: 1573-5036
    Schlagwort(e): alginate ; biological control ; Cucumis sativus ; Lycopersicon esculentum ; Meloidogyne incognita ; microbial ecology ; nematode eggs ; soil microbiology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract A method was developed for utilizing alginate films to deliver inoculum into soil and evaluate microbial antagonistic activity against nematode eggs. Eggs of Meloidogyne incognita were harvested from galled tomato roots (Lycopersicon esculentum), surface disinfested, suspended in 2% (w/v) aqueous sodium alginate, and applied to 2.5 × 5.0 cm polyvinyl chloride coated fiberglass screens (1.5 mm2 mesh size) at a uniform thickness of 0.5 mm. The alginate solution was gelled by dipping in 0.25 M CaCl2. Films containing eggs were observed in vitro and egg development was evaluated. The number of immature eggs and eggs with first stage juveniles declined linearly over time while the number of empty eggs shells, and hatched juveniles increased over time, indicating that the alginate gel did not inhibit development and motility of M. incognita juveniles. In a greenhouse experiment using cucumber (Cucumis sativus) the number of galls g-1 root was correlated with the number of eggs in alginate films placed in each pot at planting. Films containing M. incognita eggs were buried in field soil containing organic amendments, incubated, removed from soil, rinsed with water, and observed. The number of immature eggs in grids from soil amended with chitin or flax seed meal were lower than in untreated soil; percent parasitized eggs was also greater in films from amended soil than from untreated soil.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 38
    Digitale Medien
    Digitale Medien
    Springer
    Plant and soil 163 (1994), S. 77-83 
    ISSN: 1573-5036
    Schlagwort(e): actinomycetes ; biological control ; Brassica rapa ; Daucus carota ; PGPR ; rhizosphere
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Root-colonization ability of Streptomyces griseoviridis was tested on turnip rape (Brassica rapa subsp. oleifera) and carrot (Daucus carota) by the plate test and the sand-tube method. In the plate test, colonized root length of total root length was highly significantly greater for turnip rape roots (72%) from those for carrot roots (1%). In the sand-tube method, root-colonization ability was examined in nonsterile soil, and no water was added after sowing. Seeds were treated with spores of S. griseoviridis or the biofungicide Mycostop. Roots were cut into 2-cm segments, and the root segments and the rhizosphere soil were studied separately. Root-colonization frequencies and population densities of the microbe in the rhizosphere soil indicated that S. griseoviridis successfully colonized turnip rape but weakly colonized carrot. Root-colonization of turnip rape is accounted for as proliferation of S. griseoviridis in the rhizosphere of turnip rape seedlings and is not due to the movement of microbe through the rhizosphere by water infiltration.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 39
    Digitale Medien
    Digitale Medien
    Springer
    European journal of plant pathology 100 (1994), S. 279-282 
    ISSN: 1573-8469
    Schlagwort(e): ascospores ; biological control ; chinese aster ; germination ; heat resistance ; seed coating ; survival ; tomato
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Spores of the biocontrol agentTalaromyces flavus were recovered from coating material of chinese aster and tomato seeds in which they were incorporated 17 years before. The seeds had been stored at room temperature. About 20% of the ascospores had retained their heat resistance and survived treatment in aqueous suspension at 60°C for 30 min. None of the chinese aster seeds and 90% of the tomato seeds germinated after the storage period. Presence ofT. flavus during storage had not affected germinability of the seeds.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 40
    Digitale Medien
    Digitale Medien
    Springer
    European journal of plant pathology 100 (1994), S. 315-336 
    ISSN: 1573-8469
    Schlagwort(e): biological control ; Botrytis cinerea ; grey mould ; sorulation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Sixty isolates of saprophytic microorganisms were screened for their ability to reduce the severity of grey mould (Botrytis cinerea) infection and sporulation. Isolates of the bacteriaXanthomonas maltophilia, Bacillus pumilus, Lactobacillus sp., andPseudomonas sp. and the fungusGliocladium catenulatum reduced germination of conidia of the pathogen and controlled disease on bean and tomato plants. Their activity under growth room conditions was good, consistent, and similar to the activity of the known biocontrol agent,Trichoderma harzianum T39 (non-formulated). Although the tested isolates may for nutrients with the germinating conidia ofB. cinerea, resistance induced in the host by live or dead cells were also found to be involved. Inhibitory compounds were not detected on treated leaves. Sporulation ofB. cinerea after its establishment on leaves was also reduced by the above mentioned isolates and byPenicillium sp.,Arthrinium montagnei, Ar. phaeospermum, Sesquicillium candelabrum, Chaetomium globosum, Alternaria alternata, Ulocladium atrum, andT. viride. These sporulation-inhibiting fungi did not reduce the infection of leaves byB. cinerea. Most of these selected fungi and bacteria were capable of reducing lesion expansion.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 41
    Digitale Medien
    Digitale Medien
    Springer
    European journal of plant pathology 100 (1994), S. 337-346 
    ISSN: 1573-8469
    Schlagwort(e): Trichoderma spp. ; biological control ; increased growth response ; PGPR ; damping-off
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Trichoderma harzianum was applied to cucumber and pepper seedlings as a peat-bran preparation incorporated into the propagative mixture in a commercial production nursery. On marketing day (after 18 and 30 days for cucumber and pepper, respectively), significant increases of 23.8% and 17.2% in seedling height, 96.1% and 50% in leaf area, and 24.7% and 28.6% in plant dry weight were observed in cucumber and pepper seedlings, respectively, as compared to their non-treated counterparts.Trichoderma-treated seedlings were much more developed and vigorous and had higher chlorophyll contents. No significant differences were found in N, P or K content between treatments. Cucumber seedlings were then transplanted to a commercial greenhouse and analyzed over two successive growth cycles following soil fumigation with methyl bromide (500 kg/ha). Results revealed theTrichoderma-treated plants to be more resistant to damping-off disease. During the first cycle, immediately after soil fumigation, no damping-off was observed with either treatment, except in border beds where 4% of the non-treated plants died, as compared to no damping-off in theTrichoderma-treated plants. During the second growing cycle however, significant reductions in damping-off of 67% and 52% were obtained in middle and border beds, respectively, as compared to the non-treated controls.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 42
    ISSN: 1573-8248
    Schlagwort(e): predatory soil mite ; biological control ; glasshouse ; development rate ; fecundity ; longevity ; rearing techniques
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Beschreibung / Inhaltsverzeichnis: Résumé Différents aspects de la biologied'Hypoaspis miles sont examinés: vitesse de développement de l'oeuf à l'adulte à différentes températures, fécondité, longévité et voracité sur les sciarides. Avec une augmentation de la température, la durée du développement passe de 33,7 jours à 15°C à 9,2 jours à 28°C. La température minimale qui permet le développement complet deH. miles est située entre 10 et 12°C. Quand il est nourri d'"itAcarus siro, H. miles pond 2 à 3 oeufs par jour et seuls les oeufs non fécondés donnent des mâles. Les adultes deH. miles (âgés de 0 à 1 jour) survivent pendant 24±1,4 jours sans nourriture et si elles sont nourries pendant 6 jours puis privées de nourriture, les femelles vivent 65,4±2,6 jours, ce qui est significativement plus long que les mâles (45,2±3 jours). Avec de la nourriture, 60% des mâles et des femelles vivent pendant 142 jours. Toutes les larves de sciarides sont attaquées parH. miles, mais le nombre de proies consommées dépend de la taille des larves. La prédation des oeufs est négligeable et les pupes ne sont pas attaquées. Dans des études sur la productivité deH. miles en élevage (nourri deA. siro), la durée nécessaire aux acariens pour atteindre une densité de 45–65 000/1 est de 76 et 23 jours à 15°C et 28°C respectivement.
    Notizen: Abstract The following aspects ofHypoaspis miles' biology were investigated; development rate of egg to adult at different temperatures, fecundity, longevity and rate of predation on sciarids. With an increase in temperature the time taken for development decreased from 33.7 days at 15°C to 9.2 days at 28°C. The threshold temperature forH. miles to complete its life cycle was between 10° and 12°C. When fed onAcarus siro, H. miles laid 2–3 eggs a day and unfertilized eggs only developed into males. Adults ofH. miles (0–1 day old) survived for 24.0±1.4 days without food and if fed for 6 days and then starved, females lived for 65.4±2.6 days which was significantly longer than males (45.2±3.0 days). With food, 60% of males and females survived for 142 days. All larval instars of sciarids were attacked byH. miles although the numbers consumed were dependent on the size of the larvae. Egg predation was negligible and pupae were not attacked. In productivity studies ofH. miles in culture (fed onA. siro), the time taken for the mites to reach a density of 45–65,000/litre ranged from 76 to 23 days at 15° and 28°C respectively.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 43
    Digitale Medien
    Digitale Medien
    Springer
    BioControl 39 (1994), S. 323-333 
    ISSN: 1573-8248
    Schlagwort(e): Abax parallelepipedus ; biological control ; mass breeding ; soil capsule ; growth rate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Beschreibung / Inhaltsverzeichnis: Résumé Des travaux précédents ont montré qu'Abax parallelepipedus Piller & Mitterpacher est un prédateur de limaces sur le terrain et peut être employé efficacement pour leur contrôle dans les tunnels en polyéthylène. Pour que la lutte biologique soit réalisable, ce carabe doit aussi pouvoir être produit massivement. La préparation du substrat garantit que les oeufs soient pondus dans des boulettes de terre, mais déposés dans de la tourbe, ce qui facilite la récolte et la surveillance. Un carabe peut pondre jusqu'à 570 oeufs/femelle, à une température constante de 20 °C. Quel que soit le stade de développement de cette espèce, aucun cannibalisme n'a été observé. Les larves sont élevées intensivement en groupes et nourriesad libitum de vers de terre vivants, ce qui élimine ainsi la nécessité d'apporter régulièrement les aliments et de retirer la nourriture en décomposition. Les expériences d'élevage ont été menées à differents régimes de températures. A une température constante de 20 °C, la croissance s'arrête pendant une longue période chez plusieurs larves de deuxième stade. La réduction de température à 14 °C, durant les 24 à 31 jours après l'éclosion, induit la synchronisation des passages du deuxième au troisième stade larvaire. Le cycle de vie complet, depuis la ponte de l'oeuf jusqu'au carabe adulte, peut être réduit à moins de 110 jours. La mortalité est la plus élevée à la fin du troisième stade larvaire et au stade pré-pupal, et les causes possibles en sont discutées.
    Notizen: Abstract Previous work has shown thatAbax parallelepipedus Piller & Mitterpacher preys upon slugs in the field, and can be effectively employed to control slugs in polythene tunnels. To be a viable biological control agent this carabid must also be amenable to mass culturing. Manipulation of the substrate ensured that eggs were laid in soil capsules, but deposited in peat, facilitating collection and monitoring. Up to 570 eggs per beetle were laid at 20°C. No cannibalism was exhibited at any stage by this species. Larvae were reared intensively in batches and fed ad libitum on live earthworms, eliminating the need for regular feeding and the removal of decaying food. Rearing experiments were undertaken under a number of different temperature regimes. At constant 20°C it was found that growth was arrested in some 2nd instar larvae for long periods. Co-ordinated changes between 2nd and 3rd instar stages were induced by reduction of the temperature to 14°C between days 24–31 from hatching. The complete life cycle, from newly laid egg to adult beetle, could be reduced to less than 110 days. Mortality was greatest at the late 3rd instar and pre-pupal stages, and possible reasons for this are discussed.
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  • 44
    Digitale Medien
    Digitale Medien
    Springer
    BioControl 39 (1994), S. 335-340 
    ISSN: 1573-8248
    Schlagwort(e): Chrysomelidae ; weed ; Acacia ; host specificity ; oviposition ; biological control
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Beschreibung / Inhaltsverzeichnis: Résumé Au Kenya, la chrysomèle phytophage,Weiseana barkeri Jacoby, se nourrit surAcacia nilotica (L.) Willdenow ex Delile. Des essais de spécificité à l'hôte montre que cette espèce est strictement spécifique àA. nilotica: l'autorisation de lâcher dans le nord ouest du Queensland a donc été demandée pour cet auxiliaire carA. nilotica est considérée comme une plante nuisible dans les zones de pacage de troupeaux dans cette région d'Australie. En outre, une nouvelle technique d'élevage et de tests de spécificité à l'hôte est rappotée dans laquelle la présence de feuillage deA. nilotica permet de stimuler l'oviposition deW. barkeri sur des bandes de carton ondulé.
    Notizen: Abstract The leaf-feeding beetleWeiseana barkeri Jacoby feeds onAcacia nilotica (L.) Willdenow ex Delile in Kenya. Host specificity tests show it is host specific toA. nilotica and approval has been given for its field release in northwest Queensland. A novel rearing and host specificity-testing technique is reported whereA. nilotica foliage stimulates oviposition into strips of corrugated cardboard.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 45
    ISSN: 1573-8248
    Schlagwort(e): biological control ; weeds ; Compositae ; Centaurea ; moths
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Beschreibung / Inhaltsverzeichnis: Résumé La biologie de la PhalènePterolonche inspersa (Staudinger) (Lepidoptera: Pterolonchidae) a été étudiée dans le Sud de l'Europe. Les larves vivent dans les racines deCentaurea diffusa De Lamarck et deC. maculosa De Lamarck. Les larves de premier stade n'infestent pas les Compositae d'importance économique des genresCynara L.,Helianthus L.,Zinnia L. etCalendula L.P. inspersa est largement répandue dans la zone étudiée, et se retrouve à la fois dans des populations denses ou dispersées de la plante hôte, en général sur des sols sableux ou rocheux. Il n'existe qu'une seule génération par an. Les larves se nourrissent dans les racines pendant environ 11 mois (août–septembre à juillet–août de l'année suivante). Au laboratoire, les adultes émergent entre mi-juillet et fin août, le pic d'émergence se situant à la mi-août. Sur le terrain, les adultes sont observés tout au long du mois de juillet. L'oviposition a été observée à partir du 10 juillet jusqu'à la fin du mois. Les œufs sont déposés isolément ou en groupes de 5 ou 6 sur des rosettes, solidement fixés aux feuilles des plantes-hôtes. Au laboratoire, les adultes s'accouplent au cours des 24 heures suivant l'émergence. La période de pré-oviposition dure 2,6±0,8 jours et la période de l'oviposition 7,4±2,2 jours. Le nombre moyen d'œufs pondus est de 142,2±59,2 par femelle. La durée moyenne d'incubation est de 12±4,7 jours, le stade durant 14,7±2,4 jours. La durée de vie des femelles est supérieure à celle des mâles: 15,8±2,4 au lieu de 10,7±1,4 jours.
    Notizen: Abstract The moth,Pterolonche inspersa (Staudinger) (Lepidoptera: Pterolonchidae), is widely distributed in southern Europe, north Africa, Turkey and the former Soviet Union. It occurs in both thick and scattered stands of knapweeds in disturbed sites, usually on sandy and/or stony soil. Larvae bore in the roots of diffuse and spotted knapweeds (Centaurea diffusa De Lamarck andC. maculosa De Lamarck). There is one generation per year in northern Greece, and larvae feed in the roots for about 11 months during the growing season (August–September, to the following July–August). In the laboratory garden, emergence took place between the second half of July and the end of August, with peak emergence during mid August. In the field, adults were observed from early to late July. Female moths oviposited on rosettes during the first ten days of July and continued through the end of July. Eggs were laid singly or in groups of five or six, firmly attached to the leaves of the host plant. In the laboratory, females mated within 24 hours of emergence and the preoviposition period lasted 2.6±0.8 days. The oviposition period lasted 7.4±2.2 days and the average number of eggs per female was 142.2±59.2. The incubation period was 12±4.7 days; the pupal stage lasted 14.7±2.4 days; and females lived 15.8±2.4 days, while males lived 10.7±1.4 days. First instar larvae failed to survive on economically important Compositae in the generaCynara L.,Helianthus L.,Zinnia L. andCalendula L. (Dunnet al., 1989).
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 46
    ISSN: 1573-8248
    Schlagwort(e): Coccinellidae ; Coleomegilla maculata ; Bacillus thuringiensis ; Leptinotarsa decemlineata ; biological control ; toxicity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Beschreibung / Inhaltsverzeichnis: Résumé Des bioessais en laboratoire ont été effectués afin de déterminer si les larves de la coccinelle maculée,Coleomegilla maculata lengi Timberlake (Col.: Coccinellidae), sont affectées par M-One™, un insecticide biologique préparé à partir de la bactérieBacillus thuringiensis var.san diego Berliner et utilisé dans la lutte contre le doryphore de la pomme de terre,Leptinotarsa decemlineata (Say) (Col.: Chrysomelidae). Le développement larvaire, effectué sur du pollen traité avec des concentrations de 20 ml M-One™/litre (5,6×108 unités internationales de doryphore/litre) et 200 ml M-One™/litre, a nécessité 29,3 et 38,5 jours respectivement, comparativement à 21,9 jours pour le témoin (eau). M-One™ n'a pas causé de mortalité chez les larves. Au cours d'un test de 48 h, les larves de stade III n'ont montré aucune préférence entre des œufs traités avec 20 ml M-One™/litre et des œufs traités avec de l'eau. Par contre avec 200 ml M-One™/litre, le nombre d'œufs attaqués a diminué significativement de 34,7% par rapport au témoin, 48 h après le début du test. Ces résultats indiquent que l'utilisation de M-One™ à la concentration recommandée de 20 ml/litre ne représente pas une menace pour les populations larvaires de la coccinelle maculée.
    Notizen: Abstract Laboratory experiments were conducted to determine the effects of M-One™ (Bacillus thuringiensis var.san diego) on larval instars ofColeomegilla maculata lengi Timberlake. Coccinellid larval development (from egg hatch to adult), completed on pollen treated with suspensions of M-One™ at 20 ml/litre (5.6×108 CPBIU/litre) and 200 ml/litre, took respectively 29.3 and 38.5 days compared with 21.9 days for the control (water). M-One™ did not cause larval mortality.C. maculata third instars did not show any preference between eggs ofLeptinotarsa decemlineata (Say) treated with water or with M-One™ at 20 ml/litre. However, at 200 ml M-One™/litre, the number of eggs attacked was 34.7% lower than the eggs treated with water only, 48 h after the beginning of the test. These results indicate that the use of M-One™, at the manufacturer's recommended field rate of 20 ml/litre, does not cause a major threat to larvalC. maculata populations.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 47
    ISSN: 1573-8248
    Schlagwort(e): Podisus maculiventris ; Leptinotarsa decemlineata ; Pieris brassicae ; biological control ; predation rate ; development rate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Beschreibung / Inhaltsverzeichnis: Résumé Des recherches de terrain ont été menées afin d'étudier le degré de prédation journalier et l'effet de la proie sur le développement et la survie des différents stades nymphaux deProdisus maculiventris Say en présence de larves du 3e stade deLeptinotarsa decemlineata (Say) et dePieris brassicae (Linnaeus). Les résultats obtenus montrent que les nymphes du 5e stade et les adultes du prédateur ont une importante activité prédatrice avec un taux de survie élevé quand ils se nourrissent aux dépens de larves du doryphore ou de la Piéride du chou. Par conséquent, il est très probable quePodisus pourrait être utilisé contre ces ravageurs dans des zones où les conditions climatiques sont proches de celles de la région de Thessaloniki (Grèce du Nord).
    Notizen: Abstract The mean predation rate per day and the effect of the prey on the development and survival of the various nymphal stages ofPodisus maculiventris (Say) were studied under field-cage conditions. Third instar larvae of the Colorado potato beetleLeptinotarsa decemlineata (Say) and the large white butterflyPieris brassicae (Linnaeus) were used as the prey. The results show that under climatic conditions similar to those occurring in the Thessaloniki region (N. Greece), the 5th instar nymphs and the adults of the predatorP. maculiventris would be promising agents for the biological control of larvae ofL. decemlineata andP. brassicae.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 48
    ISSN: 1573-8248
    Schlagwort(e): biological control ; cantharid ; supplementary food ; coccinellids
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Beschreibung / Inhaltsverzeichnis: Résumé Chrysophtharta bimaculata Olivier (Col. Chrysomelidae) est un défoliateur important des régénérations d'eucalyptus en Tasmanie: il cause une forte réduction de l'accroissement en hauteur et en diamètre des arbres, réduisant ainsi le cubage de bois produit à l'hectare. En 1991 et 1992, une étude pour conserver et accroître l'efficacité de coccinelles, principalementCleobora mellyi Mulsant (Col.: Coccinellidae), et d'une cantharide,Chauliognathus pulchellus (Macleay) (Col.: Cantharidae) comme agents de lutte biologique, a été faite dans les jeunes peuplements forestiers de Tasmanie du sud pour la lutte biologique deC. bimaculata. Les cantharides adultes et les adultes et larves de coccinelles se nourrissent des œufs deC. bimaculata et à un degré moindre, des jeunes larves. L'activité des coccinelles était la plus importante pendant le stade œuf et les premier et deuxième stades larvaires deC. bimaculata. Les cantharides n'étaient actives que durant le stade œuf de la proie puis disparaissaient de la parcelle. Les coccinelles étaient donc les prédateurs les plus utiles, mais leur population diminuait lorsque la proie atteignait les 3e et 4e stades larvaires. Comme le manque de nourriture pouvait être à l'origine de leur diminution, un complément de nourriture a été fourni sous forme de pulvérisation de saccharose ou de granules de sucre déposées à une station de nourrissage. Ceci a provoqué le maintien des populations des deux prédateurs, particulièrement des coccinelles, et a augmenté leur efficacité.
    Notizen: Abstract Chrysophtharta bimaculata (Olivier) (Coleoptera: Chrysomelidae) is a major defoliator of regeneration eucalypt trees in Tasmania causing a significant reduction in height and diameter increment of trees which reduces wood volume per hectare. A study to conserve and enhance the efficiency of coccinellid species chieflyCleobora mellyi (Mulsant) (Coleoptera: Coccinellidae), and the cantharid,Chauliognathus pulchellus (Macleay) (Coleoptera: Cantharidae), for the biological control ofC. bimaculata was conducted in young regeneration forests in southern Tasmania from 1991–92. Cantharid adults and coccinellid adults and larvae feed onC. bimaculata eggs and, to a lesser extent, young larvae. The study found that coccinellids were more active throughout the egg and early (1st and 2nd) stage ofC. bimaculata. The cantharid, however was active only during the egg stage of the prey and then disappeared from the plantation. The coccinellids were therefore the most useful predators, but their population declined when the prey reached the 3rd and 4th stages. As shortage of food may account for this decline, supplementary food was provided in the form of sucrose sprays or sugar granules at a feeding station. This resulted in the retention of both predators and particularly the coccinellids and enhanced their efficacy.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 49
    ISSN: 1573-8248
    Schlagwort(e): Aphodius ater ; Aphodius sphacelatus ; Sphaeridium bipustulatum ; Dictyocaulus sp. ; biological control ; Pilobolus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Beschreibung / Inhaltsverzeichnis: Résumé L'effet de l'activité d'Aphodius spacelatus et deA. ater dans les bouses de vaches et deSphaeridium bipustulatum dans les fèces de moutons et de chevaux, sur la libération de sporanges parPilobolus a été étudié en conditions de laboratoire. Sur 5 essais le nombre médian de sporanges libérés dans des cellules expérimentales (avec 1 ou 2 bousiers/g fèces) était significativement inférieur (P〈0.01) à celui obtenu dans des cellules témoins (sans bousier). De plus, le pourcentage médian de réduction des sporanges est significativement plus élevé (P〈0,01) pourA. sphacelatus (80,9%) que pourA. ater (56,9%) à la densité de 1 bousier/g de bouse.
    Notizen: Abstract The effect ofAphodius sphacelatus andA. ater activity in cattle faeces andSphaeridium bipustulatum in sheep and horse faeces on the discharge ofPilobolus sporangia was investigated under laboratory conditions. In five trials, the median number of sporangia produced was significantly less (P〈0.01) in experimental chambers (with 1 or 2 beetles/g faeces) than in control chambers (without beetles). In addition, median percentage reduction of sporangia was significantly higher (P〈0.01) forA. sphacelatus (80.9%) than forA. ater (56.9%) at 1 beetle/g cattle faeces.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 50
    ISSN: 1573-8248
    Schlagwort(e): Plutella xylostella ; Diadegma semiclausum ; Cotesia plutellae ; superparasitism ; multiparasitism ; biological control
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Beschreibung / Inhaltsverzeichnis: Résumé Des expériences ont été menées en laboratoire afin d'étudier les caractéristiques du parasitisme dePlutella xylostella (L.), ravageur des crucifères de répartition mondiale, par un parasitoïde larvaire,Diadegma semiclausum Hellén. Les résultats montrent que plus la densité des larves-hôtes est importante, plus le pourcentage de larves parasitées est faible. La surface explorée décroît avec l'augmentation de la densité du parasitoïde mais la valeur de k est pratiquement invariable. Le parasitisme réduit la consommation alimentaire des chenilles. Aucune différence n'est observée quant à la durée des stades larvaires entre larves parasitées et larves non parasitées. La proportion de femelles augmente avec l'accroissement de la fréquence du superparasitisme. La présence de larves du parasitoïde à l'intérieur de la larve-hôte limite davantage le superparasitisme que la présence d'oeufs du parasitoïde. La présence de larves deD. semiclausum ou d'un autre parasitoïde larvaire,Cotesia plutellae Kurdjumov, à l'intérieur des larves-hôtes freine davantage le multiparasitisme par l'une ou l'autre des espèces que la présence d'oeufs de l'un ou l'autre parasitoïde.D. semiclausum est beaucoup plus aggressive queC. plutellae pour parasiter les larves deP. xylostella.
    Notizen: Abstract Laboratory experiments were conducted to study the characteristics of parasitism of diamondback moth,Plutella xylostella (L.), a worldwide pest of crucifers, by a larval parasite,Diadegma semiclausum Hellén. Results showed that the greater the host larval density, the lesser was the percentage of larvae parasitized. The area of discovery decreased with increasing parasite density, but k-value remained practically unchanged. Parasitism reduced food consumption in parasitised larvae. No difference was observed in duration of larval instars between the parasitized and healthy larvae. As the frequency of superparasitism increased, the proportion of production of female progeny also increased. Presence of parasite larva within the host larva deterred superparasitism greater than the presence of parasite egg. Presence of larva of eitherD. semiclausum or another larval parasite,Cotesia plutellae Kurdjumov, within host larva deterred multiparasitism by either species greater than the presence of egg of either parasite species.Diadegma semiclausum was much more aggressive thanC. plutellae in parasitisingP. xylostella larvae.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 51
    ISSN: 1573-8248
    Schlagwort(e): Dendroctonus micans ; Rhizophagus grandis ; Scolytidae ; Rhizophagidae ; biological control ; mass-rearing ; flight ; take-off ; windtunnel ; quality control
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Beschreibung / Inhaltsverzeichnis: Résumé Le temps passé en conservation à basse température (3–7°C) depuis la métamorphose est intervenu pour 81% dans la perte de la capacité d'envol chez le coléoptère prédateurRhizophagus grandis Gyll. lors d'expériences en tunnel de vol. A l'âge de trois semaines, les insectes sont à leur plus haut niveau d'envol (envol d'environ 80% des insectes). Par la suite, il y a un déclin constant de la capacité d'envol, à raison de 7% des insectes chaque mois. Des changements dans les réserves lipidiques peuvent partiellement expliquer cette réduction, bien qu'il n'y ait pas eu de différence entre le poids frais d'insectes capables de s'envoler et celui d'individus qui en étaient incapables. Le sexe a une influence sur le taux d'envol, avec un taux d'envol significativement plus élevé de 8.7% chez les femelles. La capacité d'envol est encore réduite chez des insectes qui ont été produits dans des élevages de masse où les parents étaient soumis à un mélange de stimuli de ponte de synthèse au lieu d'être mis en présence de larves deD. micans vivantes. Chez les insectes qui prennent leur vol, cependant, la réponse aux attractifs de synthèse est indépendante de l'âge ainsi que des conditions d'élevage.
    Notizen: Abstract Time spent by adult beetles in cold storage at 3–7°C accounted for 81% of the loss of take-off capacity inRhizophagus grandis Gyllenhal in windtunnel experiments. At the age of three weeks, the insects were at their highest take-off capacity at about 80%. This was followed by a steady decrease, 7% of the insects failing to take-off each month. Changes in the fat reserves during cold storage could explain at least partly this reduction of flight capacity although there was no significant difference in fresh weight between insects that were able/unable to take-off. Sex had a significant influence on take-off rates, with an 8.7% higher take-off rate in females. Take-off capacity was further reduced when the insects were mass-produced in cultures using parent beetles submitted to a blend of synthetic oviposition stimulants instead of live prey larvae. Response to synthetic attractants by those insects which took-off, however, was not influenced by cold storage or by the use of synthetic stimulants in the culture medium.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 52
    Digitale Medien
    Digitale Medien
    Springer
    Potato research 36 (1993), S. 35-42 
    ISSN: 1871-4528
    Schlagwort(e): Solanum tuberosum L. ; disease screening ; maturity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Fourteen genotypes of potato were assessed for resistance toAlternaria solani Sor., both in the glasshouse at the Scottish Crop Research Institute in Scotland and in the field in the Negev, Israel. Glasshouse assessments agreed well with field results, identifying the most resistant and susceptible genotypes. The effects on the glasshouse test of plant age, inoculum concentration, and length of time plants were kept damp after inoculation, were examined. The best agreement with field results was shown by plants inoculated at flowering, and the best discrimination between genotypes was achieved by keeping the foliage damp for 24 h after inoculating with a spore suspension containing 2.5×103 spores/ml.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 53
    Digitale Medien
    Digitale Medien
    Springer
    Potato research 36 (1993), S. 283-292 
    ISSN: 1871-4528
    Schlagwort(e): Solanum tuberosum L. ; rapid multiplication ; seed production ; non-destructive harvest ; physiological age ; cultivar ; stem number
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Minitubers of cultivars Agria and Liseta were harvested from the same plantlets on three dates. After each harvest, tubers were dried (1 day), cured (13 days) and cold stored at 2 °C in darkness and 80 % RH. Their performance was studied 65, 128, 191, 254, 317, 380, 443, 506 and 569 days after harvest. Minitubers (1–2 g) were planted in pots and grown for 8 weeks in a controlled environment. After 191 days of storage their growth was still extremely poor. In both cultivars, tallest plants and largest leaf areas per plant were observed in plants from tubers from the second and third harvests that had been stored for 317 days. Highest stem numbers, yields (total dry matter, tuber fresh weight) and harvest indices were achieved with 443 days storage with cv. Agria and 569 days storage with cv. Liseta. Tubers from the first harvest behaved slightly differently.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 54
    Digitale Medien
    Digitale Medien
    Springer
    Potato research 36 (1993), S. 143-151 
    ISSN: 1871-4528
    Schlagwort(e): Solanum tuberosum L. ; Warmlagerung ; Keimintensität ; Schwund ; Aufgangsverspätung ; Bestandesdichte ; Ertrag
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Beschreibung / Inhaltsverzeichnis: Summary Seed tubers were stored at above optimal temperatures. Mean temperatures varied during test years from 16 to 29.5°C (in 1988–1990 tubers desprouted before planting; in 1991 chitted tubers as in control; Table 1). This procedure of physiological ageing of seed tubers resulted in reduced plant density and lower yield compared to the chitted control in every year of the test period (average of 25 cultivars). The emergence was significantly delayed as compared to the control in all years (Table 2). Assessed for yield, the cultivars Désirée, Sanetta, Astilla and Andra showed a significantly higher degree of tolerance to warm storages (〉80%, when compared to the control) than the cultivars Arkula, Dorisa, Karlena and Koretta (〈25%; Table 3). Between these two extremes there was a large number of intermediate levels of tolerance, a result of fluctuating reactions of various cultivars to changing conditions in the years of the test period (Fig. 1). No correlation could be found between the cultivars' reactions and their maturity group or their sprouting behaviour. There was, however, for each cultivar a significant negative correlation between loss in weight through transpiration and respiration and plant density and yield (r=−0.55 and −0.54; Table 4). Plant density and yield were closely correlated (Table 4). The regressions between loss of plants and reductions in yields show that after seed tuber storage at higher temperatures a reduced yield must be expected even when plant density is not reduced (loss of plant 0%; Fig. 2). With complete stands, the use of physiologically aged seed tubers that were desprouted before planting (1988–1990) resulted in a reduction of yield of 17–20%; when old seeds were chitted as in control a loss in yield of 15% was calculated.
    Notizen: Zusammenfassung Die physiologische Alterung der Pflanzknollen durch Lagerung bei überoptimalen Temperaturen (jahresunterschiedlich 16–29,5°C, 1988–90 vor dem Pflanzen abgekeimt, 1991 vorgekeimt wie Kontrolle) führte im Vergleich zur vorgekeimten Kontrolle im Mittel von 25 Sorten in allen Versuchsjahren zu einer Verminderung der Bestandesdichte und des Ertrages. Eine Gruppe von Sorten erwies sich in allen Jahren als relativ tolerant gegen die Alterung, eine andere als signifikant empfindlicher, dazwischen lag ein breites Mittelfeld mit zum Teil erheblichen Schwankungen in den Jahren. Die Reaktion der Sorten zeigte keine Beziehung zu ihrer Reifegruppe und ihrer Keimintensität, dagegen war die sortentypische Ertragsdepression nicht sehr eng, aber signifikant mit dem Schwund während der Lagerung korreliert.
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  • 55
    ISSN: 1871-4528
    Schlagwort(e): Solanum tuberosum L. ; Phytophthora infestans
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary The effect of the moisture level of potting compost at harvest on the susceptibility of tubers of three cultivars to late blight was investigated in the glasshouse in three successive years. Three moisture regimes (dry, moist, wet) were imposed at flowering time, the tubers harvested 3 weeks later and immediately dipped in a zoospore suspension ofPhytophthora infestans. Tubers from dry compost were significantly more susceptible than those from wet or moist compost, which showed similar levels of susceptibility.
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  • 56
    ISSN: 1871-4528
    Schlagwort(e): culture filtrate ; resistant variants ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Cells of seven potato cultivars were selectedin vitro with culture filtrate (CF) ofPhytophthora infestans (Mont.) de Bary. Regenerated plants were tested for late blight resistance. The aim of the study was to check the efficacy of CF in the selection of potatoes for resistance to late blight and to evaluate the effects of additive factors on general resistance. One selection cycle, applied to a cell culture system, selected cells resistant to toxic metabolites of CF.In vivo screening of clones regenerated from selected cells was done in two steps: on whole plants, assessing foliage late blight, and on detached leaves, assessing single factors of horizontal resistance. In general, the frequency of resistant variants selected with CF did not differ from that of resistant somaclonal variants. Nevertheless, high concentrations of CF in the growth medium seemed to induce an improvement of some partial resistance factors as compared with the source plants.
    Materialart: Digitale Medien
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  • 57
    ISSN: 1871-4528
    Schlagwort(e): foliage blight ; tuber blight ; Phytophthora infestans ; breeders' preference score ; specific combining ability ; potato ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Screening tests to detect resistance to late blight in both foliage and tubers were done on glasshouse-grown seedling progenies in parallel with visual assessments by three experienced potato breeders of the yield and quality of glasshouse-grown tubers of the same progenies. There were large differences between the parents of the progenies in their general combining ability (GCA) for both foliage and tuber blight, despite some variation due to specific combining ability for foliage blight. There were also differences between parents in their GCAs for visual preference scores, but these GCAs and those for blight resistance were not correlated. The blight-resistant cv. Stirling had the best combination of high GCAs for all three attributes. The use of these and other seedling progeny tests in a multitrait genotypic recurrent selection scheme is discussed.
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  • 58
    ISSN: 1871-4528
    Schlagwort(e): Solanum tuberosum L. ; seed size ; rapid multiplication ; seed production ; non-destructive harvest ; water loss
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Storage losses were studied in minitubers of cvs Agria and Liseta, using five fresh weight classes (〈0.50 g, 0.5–0.99 g, 1.00–1.99 g, 2.00–2.99 g, ≥3.00 g), and three successive harvests of the same plantlets. After each harvest, tubers were dired at room temperature (1 day), curred at 18 °C (13 days) and stored at 2 °C (540 days). Two kinds of storage losses were considered: (a) losses of entire tubers because of deterioration, and (b) fresh weight losses of the other tubers. Both kinds of losses were higher in cv. Liseta, in tubers with lower fresh weights and in tubers from the first harvest. Almost all minitubers ≥0.5 g from later harvests and from both cultivars survived storage for 1.5 years. Deterioration occurred mainly from 6 to 12 months of storage. Tubers which deteriorated during cold storage had already shown high weight losses during curing.
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  • 59
    Digitale Medien
    Digitale Medien
    Springer
    Potato research 36 (1993), S. 365-372 
    ISSN: 1871-4528
    Schlagwort(e): gametophytic selection ; reciprocal differences ; GA ; dwarfs ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary A selected clone ofSolanum tuberosum Group Andigena PI 347773 (clone Adg 11.1) and the cultivar Superior had previously been shown to be heterozygous at a gibberellin related dwarfing locus, ga1. Experiments were conducted to test for gametophytic selection for alleles at the ga1 locus in reciprocal crosses and for the effect of genotype on tuber yield. The genotypes of individuals from superior-Adg 11.1 reciprocal F1 families were determined by test crossing. Genotypic classes could be distinguished by the percentages of dwarf seedlings in their test cross progeny. No differences were found in the genotypic distributions of the reciprocal families, which indicates gametophytic selection at this locus is not the cause of reciprocal yield differences. Superior-Adg 11.1 individuals classified by ga1 locus genotype were evaluated for tuber yield. Tuber yields were highly correlated with genotype in both reciprocal families. Yields followed the pattern of simplex〉duplex〉triplex, indicating that the recessive mutant ga1 allele exhibited a dose effect stimulating yield.
    Materialart: Digitale Medien
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  • 60
    ISSN: 1871-4528
    Schlagwort(e): Solanum tuberosum L. ; seed size ; rapid multiplication ; seed production ; non-destructive harvest ; cold treatment ; sprouting
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Dry-matter concentration and dormancy were studied in minitubers of cvs Agria and Liseta, using five fresh weight classes (〈0.50 g, 0.50–0.99 g, 1.00–1.99 g, 2.00–2.99 g and ≥3.00 g) and three successive harvests of the same plantlets. The average dry-matter concentration increased with tuber weight for tubers from the second and third harvests. In minitubers ≥0.5 g, dry-matter concentration was higher in tubers from later harvests. The dormant period (days from harvest to 50% sprouting) was longer in minitubers with lower than higher weights, and longer in tubers from the first harvest than from later harvests. A cold-storage period of 6 weeks, starting 14 days after harvest, reduced the dormant period by an average of 11 days.
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  • 61
    Digitale Medien
    Digitale Medien
    Springer
    Potato research 36 (1993), S. 359-364 
    ISSN: 1871-4528
    Schlagwort(e): glutamine ; arginine ; valine ; histidine ; asparagine ; proline ; tyrosine ; methionine mixture ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Amino acids and sugars were removed from slices of potato of the cultivar Record. The slices were then soaked in solutions of the amino acids and various concentrations of glucose to study their effect on the fry colour of crisps. Glutamine was an important amino acid in the development of fry colour intensity at low glucose concentrations and also contributed to the dark fry colour when combined with glucose concentrations above 0.15%. The basic amino acid arginine had a similar but lesser effect and other amino acids used gave the same effect at glucose concentrations above 0.45%. Asparagine could play an important role in the development of fry colour quality and may decrease the grey colour intensity developed by the mixture of amino acids.
    Materialart: Digitale Medien
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  • 62
    Digitale Medien
    Digitale Medien
    Springer
    Potato research 36 (1993), S. 55-61 
    ISSN: 1871-4528
    Schlagwort(e): rapid multiplication ; Solanum tuberosum L. ; stem length ; underground tubers ; variability
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary The formation of above-ground tubers on stem cuttings of eight potato cultivars was studied over three seasons. To promote tuber formation in the leaf axils, stems grown from single node cuttings were exposed to short day conditions. Tuber formation underground was reduced by covering the soil with a plastic sheet and by using single node cuttings planted with the leaf axils several centimetres above the soil surface. With all cultivars except Alpha, which produced mis-shapen tubers in all experiments, an average of 11 (maximum 40) tubers per cutting were harvested. Significant cultivar × year interactions were observed.
    Materialart: Digitale Medien
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  • 63
    ISSN: 1871-4528
    Schlagwort(e): ELISA ; hybridoma ; closterovirus ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Two monoclonal antibodies (McAbs) which react specifically with potato virus T (PVT) were produced and tested for cross reactivity with potato viruses (A, S, X, Yo, YN, leaf roll), apple stem grooving virus (ASGV) and against healthy sap. They were found to be highly specific for PVT. These two McAbs form the basis of an enzyme-linked immunosorbent assay (ELISA) for the detection of PVT in infected plant material which is of key significance for potato quarantine.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 64
    ISSN: 1871-4528
    Schlagwort(e): ELISA ; enzyme amplification ; feeding behaviour ; field resistance ; honeydew excretion ; Myzus persicae ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary The acquisition of potato leafroll virus (PLRV) byMyzus persicae nymphs from the top leaves of potato plants was studied throughout a growing season in relation to the antigen titre in those leaves and the feeding behaviour of the aphid. Secondarily-infected plants of eight potato genotypes with different levels of field resistance served as virus sources. Early in the growing season, plants were efficient sources for virus acquisition. The amount of viral antigen detected inM. persicae nymphs fed on the top leaves was strongly correlated with the titres of viral antigen in these leaves. Virus acquisition from the top leaves of older potato plants was markedly impaired and could not be correlated with their virus titre. With increasing age of the potato plants and the development of virus symptoms, the virus titre in the leaves declined and the initial weak correlation between the virus titre and field resistance ratings disappeared. Thus, screening secondarily-infected potato plants for field resistance to PLRV based on the concentration of viral antigen in leaves or in aphids fed on them should be avoided later in the growing season. The feeding rate ofM. persicae, measured by the number of honeydew droplets excreted, did not account for the reduced uptake of virus from older plants since it was not influenced by the age of the plant. Throughout the growing season, the feeding rate ofM. persicae nymphs on PLRV-infected plants was higher on genotypes with low levels of field resistance to PLRV than on genotypes with high ones.
    Materialart: Digitale Medien
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  • 65
    ISSN: 1871-4528
    Schlagwort(e): PVY ; plant breeding ; progeny tests ; genetics ; resistance ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary For potato breeding or genetical research purposes, the number of copies of a dominant major gene for resistance to potato virus Y in a parent clone can be determined by test-crossing with a susceptible parent and observing the segregation ratio of resistant to susceptible seedlings in the progeny. In a comparison of different susceptible cultivars for use in test-crosses for this purpose, their progenies differed in the clarity of symptoms and parental phenotype proved an unreliable guide. Cvs Maris Piper, Arran Peak and Dr MacIntosh were found to be suitable tester parents, Pentland Squire less so and cv. Désirée was confirmed as having a major gene conferring incomplete resistance. It was found advisable to test-cross with more than one susceptible parent.
    Materialart: Digitale Medien
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  • 66
    Digitale Medien
    Digitale Medien
    Springer
    Plant and soil 154 (1993), S. 81-88 
    ISSN: 1573-5036
    Schlagwort(e): farming system ; fertilization ; magnesium ; nitrogen ; potassium ; potato ; proteolytic enzymes ; senescence ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The influence of fertilization on senescence and nutrient remobilization in potato leaves was investigated in two farming systems on a soil with a poor potassium availability. The ‘Conventional’ farming system followed good local practices including industrial products, while in the ‘Bio-Dynamic’ farming system industrial fertilizers and synthetic pesticides were avoided. Potassium concentrations in the dry matter of mature leaves varied over a wide range. Nitrogen compounds (protein, chlorophyll) were less affected, and phosphorus concentrations in the dry matter were similar. Magnesium and potassium concentrations in the leaves were negatively correlated. In both farming systems senescence was advanced in plants with a low nutrient supply. Alkaline pyrophosphatase and aminopeptidase activities (in general highest in expanding and mature leaves) were lower and endopeptidase activities peaked earlier on plots with low fertilizer levels. A high percentage of potassium was remobilized from senescing leaves on unfertilized plots, but the phosphorus concentration remained high at the end of the season. The results suggest that the differential net remobilization of nitrogen, phosphorus and potassium depended on actual source/sink relations in the plants.
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  • 67
    ISSN: 1573-5060
    Schlagwort(e): dihaploid potato induction ; pseudogamy ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary The production of dihaploids is the first step in a potato breeding program at the diploid level. Dihaploid induction ability, dihaploid production ability and seed parent x pollinator interaction were analyzed for 28 × 3, seed parent x pollinator combinations. This is the first report on significant interaction between seed parents and pollinators. Despite this interaction, IVP 101 had a significantly higher dihaploid induction ability than the widely used pollinators IVP 35 and IVP 48. Previous findings on significant differences in dihaploid production ability between seed parents were clearly confirmed.
    Materialart: Digitale Medien
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  • 68
    ISSN: 1573-8469
    Schlagwort(e): antibiosis ; biological control ; disease resistance ; Fusarium oxysporum f.sp.dianthi ; root colonization
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The mechanisms of suppression of fusarium wilt of carnation by two fluorescentPseudomonas strains were studied. Treatments of carnation roots withPseudomonas sp. WCS417r significantly reduced fusarium wilt caused byFusarium oxysporum f. sp.dianthi (Fod). Mutants of WCS417r defective in siderophore biosynthesis (sid−) were less effective in disease suppression compared with their wild-type. Treatments of carnation roots withPseudomonas putida WCS358r tended to reduce fusarium wilt, whereas a sid− mutant of WCS358 did not. Inhibition of conidial germination of Fod in vitro by purified siderophores (pseudobactins) of bothPseudomonas strains was based on competition for iron. The ferrated pseudobactins inhibited germination significantly less than the unferrated pseudobactins. Inhibition of mycelial growth of Fod by bothPseudomonas strains on agar plates was also based on competition for iron: with increasing iron content of the medium, inhibition of Fod by thePseudomonas strains decreased. The sid− mutant of WCS358 did not inhibit Fod on agar plates, whereas the sid− mutants of WCS417r still did. This suggests that inhibition of Fod by WCS358r in vitro was only based on siderophore-mediated competition for iron, whereas also a non-siderophore antifungal factor was involved in the inhibition of Fod by strain WCS417r. The ability of thePseudomonas strains to induce resistance against Fod in carnation grown in soil was studied by spatially separating the bacteria (on the roots) and the pathogen (in the stem). Both WCS417r and its sid− mutant reduced disease incidence significantly in the moderately resistant carnation cultivar Pallas, WCS358r did not. It is concluded that the effective and consistent suppression of fusarium wilt of carnation by strain WCS417r involves multiple mechanisms: induced resistance, siderophore-mediated competition for iron and possibly antibiosis. The less effective suppression of fusarium wilt by WCS358r only depends on siderophore-mediated competition for iron.
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  • 69
    ISSN: 1573-8248
    Schlagwort(e): Lymantria dispar ; gypsy moth ; pupal parasitism ; density dependence ; biological control
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Beschreibung / Inhaltsverzeichnis: Résumé Le parasitisme nymphal deLymantria dispar a été étudié dans 15 placettes du New Jersey, de 1978 à 1988. Le principal parasitoïde était un chalcidien,Brachymeria intermedia (Nees), qui n'a été trouvé que dans 6 placettes. Le parasitisme s'observait généralement dans l'année même ou dans celle précédant l'apparition du maximum d'ooplaques deL. dispar. Un seul site montrait un taux de parasitisme dépassant 4%. Le pourcentage de parasitisme était significativement corrélé avec le nombre d'ooplaques par ha de la saison en cours et avec le nombre de nymphes par site de la saison précédente, suggérant une densité-dépendance retardée. Une analyse de régression multiple a révélé un pourcentage de parasitisme significativement corrélé avec le pourcentage d'infection par le virus de la polyhédrose nucléaire, la densité de nymphes hôtes mâles, les températures minimales moyennes en août et en mars. Une analyse canonique discriminante, effectuée pour différencier les sites avec ou sans parasitoïdes, a été significative. Les placettes avecB. intermedia présentent des populations d'hôtes et une défoliation relativement plus élevées.
    Notizen: Abstract Pupal parasitism of the gypsy moth,Lymantria dispar (L.), was monitored in 15 study plots in New Jersey from 1978 to 1988. The predominant parasitoid was a chalcidid wasp,Brachymeria intermedia (Nees), which was found in only six plots. Parasitism was generally observed in the year of or preceding the peak numbers of gypsy moth egg masses. Parasitism exceeded 4% in only one plot. Percentage parasitism was correlated significantly with numbers of egg masses per hectare in the current season and with numbers of pupae per plot in the previous season, suggesting delayed density dependence. A multiple regression analysis found percentage parasitism to be correlated significantly with percentage infection by nuclear polyhedrosis virus, density of male host pupae, and mean minimum temperature in August and March. A canonical discriminant analysis carried out to distinguish study plots with and without the parasitoid was significant. Plots withB. intermedia had relatively higher host populations and defoliation.
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  • 70
    Digitale Medien
    Digitale Medien
    Springer
    BioControl 38 (1993), S. 3-6 
    ISSN: 1573-8248
    Schlagwort(e): biological control ; thelytoky ; arrhenotoky ; sexual reproduction ; asexual reproduction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 71
    ISSN: 1573-8248
    Schlagwort(e): Psyllaephagus ; Tamarixia ; Heteropsylla ; biological control
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Beschreibung / Inhaltsverzeichnis: Résumé La fécondité en fonction de l'âge de deux parasitoïdes du psylleHeteropsylla cubana, Psyllaephagus yaseeni etTamarixia leucaenae a été étudiée en condition de laboratoire. A 25 °C,P. yaseeni présente une fécondité plus élevée (R0=192,9) queT. leucaenae (R0=71,2);T. leucaenae montre cependant une sex ratio plus faible (environ 99 % de femelles) queP. yaseeni (environ 50 %). Le taux d'accroissement potentiel (rm=0,236) deT. leucaenae était plus élevé que celui deP. yaseeni (rm=0,188). Les vitesses de développement des parasitoïdes ont été examinées à des températures constantes et fluctuantes et les équations de la vitesse de développement en fonction de la température ont été calculées. A 25 °C, la durée moyenne des générations était respectivement de 28,0 et 18,1 jours pourP. yaseeni etT. leucaenae. Aux températures de 21,5, 25 et 30 °C la durée totale de développement (de l'œuf à l'adulte) était de 28,5, 21,9 et 14,7 jours chezP. yaseeni et 19,2, 12,6 et 9,5 jours chezT. leucaenae. Le taux de parasitisme était faible et la mortalité nymphale était élevée à la température la plus basse, 21,5 °C, pour les deux parasitoïdes. Tous deux présentaient une survie faible à 100 % de HR;P. yaseeni survivait particulièrement bien à une température de 21 °C et à 44 ou 76% d'HR. P. yaseeni attribuait environ 58 % de femelles aux larves de premier stade de développement mais seulement 12 % aux larves de second stade. Environ 99 % de toutes les éclosions deT. leucaenae était constituée de femelles. La taille des femelles issues des larves de 5e stade étaient significativement supérieure à la taille de celles qui émergeaient des larves de 3e ou 4e stade.
    Notizen: Abstract Age specific fecundity of two parasitoids,P. yaseeni andT. leucaenae, of the leucaena psyllidH. cubana, were studied under laboratory conditions. At 25 °C,P. yaseeni had a greater fecundity (R0=192.9)_thanT. leucaenae (R0=71.2);T. leucaenae however had a lower sex ratio (about 99 % females) thanP. yaseeni (about 50 % females). Innate capacity for increase (rm=0.236) ofT. leucaenae was higher thanP. yaseeni (rm=0.188). Developmental rates of the parasitoids were examined at constant and fluctuating temperatures and equations of the rate of development against temperature were calculated. At 25 °C, mean generation times were 28.0 and 18.1 days forP. yaeseeni andT. leucaenae respectively. At temperatures of 21.5, 25, and 30 °C total development times (egg to adult) were 28.5, 21.9, and 14.7 days inP. yaseeni and 19.2, 12.6, and 9.5 days inT. leucaenae respectively. The level of parasitism was low and pupal mortality was high at the lower temperature of 21.5 °C for both parasitoids. Both parasitoids showed poor survivorship at 100 % RH,P. yaseeni survived particularly well (32 days) at a temperature of 21.5 °C and 44 or 76 % RH. P. yaseeni allocated about 58 % females to first instar psyllid nymphs but only 12 % females to second instars. About 99 % of allT. leucaenae births were females. Significantly largerT. leucaenae females emerged from fifth instar parasitized nymphs than third or fourth instars.
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  • 72
    ISSN: 1573-8248
    Schlagwort(e): parasitoid ; biological control ; heat shock
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Beschreibung / Inhaltsverzeichnis: Résumé Suite à une efficacité parasitaire faible des trichogrammes, constatée, dans des conditions climatiques particulières lors des lâchers de ces parasitoïdes contre la pyrale du maïs, des chocs thermiques à 35°C et 44°C pendant une durée de 6 heures sont appliqués au stade nymphal deTrichogramma brassicae Bezdenko. Deux âges sont choisis: nymphe blanche et nymphe mélanisée. Différents critères biologiques ont été étudiés pour la génération G0 ayant subi le choc de température et pour les descendants G1. Les résultats obtenus indiquent une sensibilité des deux âges, surtout à 44°C. Cette température provoque une réduction du pouvoir parasitaire de la G0 de 51% pour les individus issus des nymphes blanches traitées et de 55% pour ceux issus des nymphes mélanisées traitées. Au niveau de la génération G1, on constate une chute de la proportion des femelles dans la descendance des adultes issus des deux âges traités: réduction de 38% pour les individus issus des nymphes mélanisées; 88% pour ceux issus des nymphes blanches. Dans ce dernier cas, la génération G1 pratiquement totalement mâle, est obligatoirement sans efficacité parasitaire.
    Notizen: Abstract Trichogramma brassicae Bezdenko is used throughout Europe as an effective biological control agent against the European corn borer (Ostrinia nubilalis Hübner). However, in certain climatic regions, the biological control exerted by this parasitoid is less effective. High temperatures inside the released capsules are suspected to have a negative influence on the parasitoids. To simulate these adverse conditions, we applied heat shocks (35°C and 44°C) for 6 hours to pupae ofTrichogramma brassicae at two periods: white pupae and melanized pupae. The results showed the susceptibility of both the white pupae and melanized pupae, especially at 44°C. At this temperature, the adults (G0 generation) derived from pupae treated at any age showed reduced longevity and fecundity. Moreover, those descended from treated melanized pupae showed an emergence rate lower than that of the control. These effects reduced to half and more the parasitic efficiency of the G0 generation. For the progeny (G1 generation), we observed a decrease of the female ratio: 38% for the progeny of adults derived from treated melanized pupae; 88% for the progeny of those derived from treated white pupae. In that condition, the G1 generation, almost totally male, could not have any parasitic activity.
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  • 73
    Digitale Medien
    Digitale Medien
    Springer
    BioControl 38 (1993), S. 193-198 
    ISSN: 1573-8248
    Schlagwort(e): biological control ; predation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Beschreibung / Inhaltsverzeichnis: Résumé Des expériences menées en conditions contrôlées dans des boîtes carrées semées de trèfle ou de ray grass ont montré que les CarabesAbax parallelepipedus (Piller & Mitterpacher) etPterostichus madidus F. limitent les populations de limaces dans les champs de trèfle et de ray grass. La limitation par ces carabes se révèle aussi bonne que celle obtenue avec le molluscicide methiocarb.A. parallelepipedus semble plus efficace queP. madidus dans ce rôle, les dégâts sur le trèfle étant maintenus à un minimum.P. madidus ne limite les limaces qu'une fois le trèfle déjà attaqué.
    Notizen: Abstract Experiments conducted in sward boxes under controlled conditions showed that the carabid beetlesAbax parallelepipedus (Piller & Mitterpacher) andPterostichus madidus F. controlled slugs in a grass/clover sward. Control was shown to be as good as that by the molluscicide, methiocarb.A. parallelepipedus proved to be more successful thanP. madidus at controlling the slugs, damage to the clover being kept to a minimum.P. madidus controlled the slugs only after some damage to the clover was sustained.
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  • 74
    ISSN: 1573-8248
    Schlagwort(e): host size preference ; parasitoid ; stored product ; maize ; biological control
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Beschreibung / Inhaltsverzeichnis: Résumé La première génération d'Anisopteromalus calandrae (Howard) récoltée dans du maïs stocké commercialement en Caroline du Sud fut exposée, dans du maïs écossé, à un mélange de jeunesSitophilus zeamais Motschulsky, de toutes tailles représentant une distribution d'âge uniforme. On a observé 87% de parasitisme sur les larves comportant un tunnel de 0,9 à 1,8 mm et 6% sur les prépupes et pupes pour cette distribution d'âge. Le taux de préférence était le plus élevé pour les grosses larves-hôte (1,6 mm de diamètre), moyen pour les autres larves de 0,9 à 1,8 mm, et le plus bas pour les pupes et les petites larves. On a discuté de la sélectivité des hôtes en utilisant les paramètres de Chesson (1983): préférence, αi, probabilité de parasitisme, Pi, et index d'électivité ɛi.
    Notizen: Abstract First generationAnisopteromalus calandrae (Howard) collected from commercial stored maize in South Carolina were exposed to a mixture of all sizes of immatureSitophilus zeamais Motschulsky, representative of a uniform age distribution, in shelled maize. Eighty-seven percent of parasitism is expected on larvae with tunnel diameters of 0.9 to 1.8 mm and 6% on prepupae and pupae, given this host-size distribution. Preference was greatest for large host larvae (1.6 mm diameter), intermediate for other larvae in the range 0.9 to 1.8 mm, and least for pupae and small larvae. Host-stage preference is discussed with respect to Chesson's (1983) parameters for preference, αi, probability of parasitism, Pi, and electivity index, ɛi.
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  • 75
    Digitale Medien
    Digitale Medien
    Springer
    BioControl 38 (1993), S. 31-40 
    ISSN: 1573-8248
    Schlagwort(e): Aphidius polygonaphis ; Illinoia liriodendri ; Liriodendron tulipifera ; tuliptree aphid ; biological control ; hyperparasitoids
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Beschreibung / Inhaltsverzeichnis: Résumé Un recensement du cortège parasitaire deIllinoia liriodendri (Monell) effectué en Californie du nord de 1988 à 1990 a révélé la présence de 12 espèces de parasitoïdes primaires et de 14 espèces d'hyperparasitoïdes. Le plus abondant des parasitoïdes primaires,Aphidius polygonaphis (Fitch), importé dans les années 1970, est à présent établi dans toute la région. Sont signalés pour la première fois associés àI. liriodendri les parasitoïdes primaires suivants:A. ervi Haliday,A. avenaphis (Fitch),Praon occidentale Baker,P. unicum Smith,Diaeretiella rapae M'Intosh,Lysiphlebus testaceipes (Cresson), etMonoctonus nervosus (Haliday) [tous Hymenoptera: Braconidae: Aphidiinae] etAphelinus sp. nr.asychis Walker [Hymenoptera: Aphelinidae]. Les hyperparasitoïdes les plus abondants sontPachyneuron aphidis (Bouché) etAsaphes californicus Girault [tous deux Hymenoptera: Pteromalidae]Pachyneuron californicum Girault etCoruna clavata Walker [Hymenoptera: Pteromalidae] sont signalés pour la première fois comme hyperparasitoïdes sur Aphidiinae et Aphelinidae spp. pour le premier, et surAphelinus sp. pour le second.
    Notizen: Abstract A survey of the parasitoids ofIllinoia liriodendri (Monell) in northern California conducted from 1988–1990 revealed the presence of 12 primary and 14 hyper-parasitoid species. The most common primary parasitoid wasAphidius polygonaphis (Fitch), which was imported from the eastern United States in the 1970's and is now established throughout the area. New host records were noted forA. ervi Haliday,A. avenaphis (Fitch), Praon occidentale Baker,P. unicum Smith,Diaeretiella rapae M'Intosh,Lysiphlebus testaceipes (Cresson), andMonoctonus nervosus (Haliday) (all Hymenoptera: Braconidae: Aphidiinae), andAphelinus sp. nr.asychis Walker (Hymenoptera: Aphelinidae). The most common hyperparasitoid species werePachyneuron aphidis (Bouché) andAsaphes californicus Girault (both Hymenoptera: Pteromalidae). New hyperparasitoid host records were noted forPachyneuron californicum Girault on Aphidiine and Aphelinidae spp. andCoruna clavata Walker (Hymenoptera: Pteromalidae) onAphelinus sp.
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  • 76
    ISSN: 1573-8248
    Schlagwort(e): Mamestra brassicae ; Chrysodeixis chalcites ; parasitoid ; sweet pepper ; biological control
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Eulophus pennicornis, a hymenopteran parasitoid of several Lepidoptera, was found onMamestra brassicae in a commercial sweet pepper crop in 1990 in Belgium. The rearing of the parasitoid and some additional data on biology are described.
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  • 77
    Digitale Medien
    Digitale Medien
    Springer
    BioControl 38 (1993), S. 89-100 
    ISSN: 1573-8248
    Schlagwort(e): parasitoid ; biological control ; release of beneficial arthropods
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Beschreibung / Inhaltsverzeichnis: Résumé Entre 1975 et 1982, l'Institut de Lutte biologique “Israël Cohen” a mis en place un programme de lutte biologique contre la cochenille noire de l'olivierSaissetia oleae (Olivier) (Hom.: Coccidae). Au cours de cette période, 17 espèces d'ennemis naturels furent introduites en Israël, et les populations du ravageur retombèrent à un niveau acceptable. Le principal parasitoïde responsable de cette réduction a étéMetaphycus bartletii A. & M. (Hym.: Encyrtidae). Cet article expose le programme et apporte en outre quelques données sur la biologie des parasitoïdes introduits.
    Notizen: Abstract During the years 1975–1982, the “Israel Cohen” Inst. for Biological Control conducted a biological control project, against the black scale,Saissetia oleae (Olivier) (Homoptera: Coccidae). Seventeen species of natural enemies were introduced into Israel during that period, and their action reduced the populations of the pest to an acceptable level. The major parasitoid responsible for that transition wasMetaphycus bartletti Annecke & Mynhardt (Hymenoptera: Encyrtidae). This article describes the project and introduces some notes on the biology of the introduced parasitoids.
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  • 78
    ISSN: 1573-8248
    Schlagwort(e): biological control ; parasitism
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Two indigenous species ofTrichogramma were reared from natural populations of the blackheaded fireworm,Rhopobota naevana (Hübner) infesting cranberries in British Columbia, Canada. One was identified asTrichogramma sp. nr.sibericum Sorokina and the other wasTrichogramma minutum Riley. Percentage of parasitized hosts increased during the season in an abandoned field, but decreased in a commercial field where pesticides were used. The potential ofTrichogramma as a biological control agent against the fireworm is discussed.
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  • 79
    ISSN: 1573-8248
    Schlagwort(e): biological control ; Parabemisia myricae ; Eretmocerus debachi ; Citrus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Beschreibung / Inhaltsverzeichnis: Résumé L'aleurodeParabemisia myricae (Kuwana) est l'un des plus sérieux ravageurs des vergers de citrus dans la région métiterranéenne de l'est de la Turquie. En 1986, un parasitoïde spécifique deP. myricae, l'aphelinideEretmocerus debachi Rose et Rosen, était introduit de Californie en Turquie et lâché dans les vergers de Citrus le long de la côte méditerranéenne orientale. Au cours des années suivantes, les populations deP. myricae étaient rapidement tombées d'environ 17 aleurodes au stade immature par feuille à moins de 0,1 par feuille dans tous les vergers de citrus où les parasitoïdes ont été lâchés. De plus,E. debachi a montré une bonne capacité de dispersion et s'est bien adapté aux conditions climatiques de la région orientale. Depuis l'installation réussie deE. debachi, l'aleurode n'est plus un ravageur dangereux et il est difficile de trouver des individus non parasités dans la région méditerranéenne de l'est de la Turquie.
    Notizen: Abstract The whitefly,Parabemisia myricae (Kuwana) is one of the most serious citrus pests in the Eastern Mediterranean region of Turkey. In 1986, a host-specific parasitoid ofP. myricae, the aphelinidEretmocerus debachi Rose and Rosen, was imported from California to Turkey and released into citrus orchards along the Eastern Mediterranean coast. In the following yearsP. myricae-populations were rapidly reduced from about 17 whitefly-immature stages per leaf to less than 0.1 stages per leaf in all citrus orchards where the parasitoids were released. Furthermore,E. debachi was shown to be a good disperser and it is well adapted to the climatic conditions in the Eastern Mediterranean region. Since the successful colonization ofE. debachi, the whitefly is no longer a serious pest and it is difficult to find unparasitized individuals in the Eastern Mediterranean region of Turkey.
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  • 80
    Digitale Medien
    Digitale Medien
    Springer
    BioControl 38 (1993), S. 391-403 
    ISSN: 1573-8248
    Schlagwort(e): sex ratio ; parasitoid ; biological control ; Australia
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Beschreibung / Inhaltsverzeichnis: Résumé Dans un verger de pommier à Armidale, sur les plateaux du nord de la Nouvelle Galles du Sud la sex ratio des populations d'Aphelinus mali, un endoparasitoïde d'Eriosoma lanigerum varie de 0,51 (pourcentage de mâles) pour de faibles densités de l'hôte à des proportions favorables aux femelles pour des densités d'hôtes élevées (pourcentage de mâles compris entre 0,35 et 0,39). Cette variation dans la sex ratio est apparemment due à des différences dans l'attribution d'une descendance mâle ou femelle en fonction de la taille de l'hôte. dans la nature,A. mali parasite le puceron du pommier à tous les stades de son développement (les 4 stades larvaires et l'adulte). D'après le modèle du régime optimal de Hughes (1979), l'acceptation de l'hôte sous toutes ses formes semble être la meilleure stratégie. Cependant, il permet à l'hôte de continuer son développement (dans le cas d'un stade larvaire) ou de se reproduire (au stade adulte) jusqu'à la momification. Aucune mortalité n'est observée en laboratoire lorsque l'hôte est parasité au 1° ou au 2° stade larvaire. Des momies de petite taille récoltées sur le terrain présentent une sex ratio favorable aux mâles alors que des momies de grande taille produisent surtout des femelles. En laboratoire, la descendance issue des hôtes de faible taille (du 1° au 3° stade) présente une sex ratio qui n'est pas significativement différente de 0,5 alors que la descendance issue des hôtes de grande taille (3° et 4° stade) montre une sex ratio favorable aux femelles. Pendant l'hiver (juin–août) et le début du printemps (septembre–octobre), c'est-à-dire à la période où la population hôte dans le verger est constituée principalement de larves, le parasitoïde tend à produire autant de mâles que de femelles. En revanche, aux pics de densité de population, en été et en automne (décembre à mai) lorsque des hôtes de grande taille sont disponibles, la sex ratio est favorable aux femelles. La taille de l'hôte,E. lanigerum et celle deA. mali, sont donc des éléments importants pour la dynamique des relations hôtes-parasitoïdes.
    Notizen: Abstract In an apple orchard at Armidale, the Northern Tablelands of NSW, population sex ratios ofAphelinus mali (Haldeman), an endoparasitoid of the woolly apple aphid,Eriosoma lanigerum (Hausmann) varied from 0.51 (proportion of males) at low host densities to female-biased at high host densities (proportion of males ranged from 0.35–0.39). This shift in sex ratio seems to be caused by the differences in allocation of sons and daughters to hosts of different sizes. In the fieldA. mali parasitizes all life stages (four nymphal instars and adult) of the woolly aphid upon encountering. According to Hughes'(1979) optimal diet model, such general host acceptance seems to be the best strategy. However, it allows the host nymphs or adults to continue to develop or reproduce until about to mummify (pupate). No mortality was observed when first or second-instar hosts were parasitized in the laboratory. Field collected small mummified hosts yielded male-biased sex ratios whereas large mummified hosts produced mainly females. In the laboratory, progeny from smaller hosts (first to third-instars) produced sex ratios which were not significantly different from 0.5 whereas progeny from larger hosts (third and fourth-instars) produced female-biased sex ratio. During winter (June–August) and early spring (September–October) when the host populations in the orchard were predominantly nymphs, the parasitoid tended to allocate equal resources to male and female offspring. In contrast, at peak population densities in summer and autumn (December–May) when larger hosts were available, the sex ratios were female-biased. The host size ofE. lanigerum andA. mali is, therefore, an important component in the dynamics of host-parasitoid interactions.
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  • 81
    Digitale Medien
    Digitale Medien
    Springer
    BioControl 38 (1993), S. 537-539 
    ISSN: 1573-8248
    Schlagwort(e): Life cycle ; host specificity ; Pachycerus cordiger ; Heliotropium europaeum ; Boraginaceae ; biological control
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The univoltine weevilPachycerus cordiger Germar (=P. scabrosus Brullé) completes its life cycle on species of Boraginaceae, it is found from western Europe to the Middle East. In southern France, adultP. cordiger were collected feeding on the leaves ofHeliotropium europaeum L.,Echium vulgare L. andCynoglossum creticum Miller, whereas larvae were found feeding externally on the roots of the three plant species from within an earthen cell. BecauseP. cordiger is considered too much of a generalist to be released in Australia, work on the weevil as a potential biological control agent ofH. europaeum has been stopped.
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  • 82
    Digitale Medien
    Digitale Medien
    Springer
    BioControl 38 (1993), S. 579-586 
    ISSN: 1573-8248
    Schlagwort(e): Plutella xylostella ; Diadegma semiclausum ; biological control ; biology ; temperature effect
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Beschreibung / Inhaltsverzeichnis: Résumé Des études en laboratoires ont été menées sur certains aspects de la biologie deDiadegma semiclausum Hellén, parasitoïde larvaire d'un ravageur des crucifères,Plutella xylostella (L.). Entre 15 et 35°C, plus la température est élevée, plus courte est la durée du développement des stades larvaires et adulte. L'éclosion et l'émergence des adultes est élevée entre 15 et 30°C mais elle est significativement réduite à 35°C. Plus la température est haute, plus la proportion de mâles est grande. Le seuil théorique de développement est de 5,74°C pour les œufs; 3,80°C pour les larves, 5,91°C pour les nymphes et 6,60°C pour les adultes. La ponte deD. semiclausum dans les larves des trois premiers stades deP. xylostella produit plus de parasitoïdes mâles que de femelles mais la ponte dans le 4e stade produit significativement plus de femelles que de mâles. Les parasites adultes ont tendance à émerger de la nymphe entre 6 h et 9 h bien que quelques individus sortent à d'autres moments de la photophase. La longévité des adultes et la production d'œufs augmentent quand on fournit aux adultes de la nourriture (miel) par rapport à l'absence de nourriture ou la fourniture d'eau seule. Des parasites adultes survivent et pondent pendant 28 jours lorsqu'on les nourrit mais seulement pendant 3 jours lorsqu'ils sont privés de nourriture.
    Notizen: Abstract Laboratory studies were conducted on certain aspects of biology ofDiadegma semiclausum Hellén, a larval parasite of a crucifer pest,Plutella xylostella (L.). Within the range of 15°C to 35°C, the higher temperature, the shorter was the duration of larval and adult stages. Egg hatching and adult emergence were high at 15°C to 30°C but were significantly reduced at 35°C. The higher the temperature, the higher was the proportion of males produced. Temperature threshold was 5.74°C for eggs, 3.80°C for larvae, 5.91°C for pupae and 6.60°C for adults.D. semiclausum oviposition in the first threeP. xylostella larval instars produced more parasite males than females but oviposition in the fourth instar produced significantly more females than males. Parasite adults tended to emerge from their pupae from 06∶00 to 09∶00 hours although some emerged at other hours during the photophase. Adult longevity and production of eggs increased when adults were provided with a food source (honey) compared with no food or provision of water alone. Parasite adults survived and laid eggs for 28 days when provided with food but for only three days when deprived of food.
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  • 83
    Digitale Medien
    Digitale Medien
    Springer
    Biology and fertility of soils 12 (1992), S. 265-271 
    ISSN: 1432-0789
    Schlagwort(e): Dehydrogenase activity ; Microbial biomass C ; Microbial biomass N ; N fertisisation ; C additions ; Soil respiration ; Solanum tuberosum L. ; Substrate-induced respiration
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary A range of soil microbiological parameters were measured at intervals throughout the growing season of a potato crop. Treatments applied to the soil at sowing were zero N fertilisation of N fertilisation at 120 kg N ha−1, either alone or supplemented with straw or sucrose at 1200 kg C ha−1. C and N flushes determined by fumigation-incubation and fumigation-extraction, and substrate-induced respiration, were measured as indicators of microbial biomass. Microbial activity was measured as respiration (CO2 production) and dehydrogenase activity (formazan production). The greatest effects were obtained from the addition of N plus sucrose. Both biomass size and activity were significantly stimulated for up to 25 days after incorporation, with the magnitude of the effects consistently diminishing over time. By 125 days after planting, there was no detectable legacy from any of the treatmentson any of the biomass parameters that were measured, and all values had reverted to those prevalent at planting. There was no consistent effect from adding N, either alone or supplemented with straw, on any of the biomass parameters. There was no evidence for crop-induced stimulation of the biomass. The experiment demonstrates that biomass is only influenced where the quantity, quality, and rate of incorporation of C into the soil is appropriate, in this case, only by adding C as a pulse of sucrose.
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  • 84
    ISSN: 1871-4528
    Schlagwort(e): ring rot ; Solanum tuberosum L. ; ELISA ; immunofluorescence ; detection
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary An indirect sandwich enzyme-linked immunosorbent assay (ELISA) was used to monitor potato stems of three cultivars for the presence of the ring rot pathogen,Clavibacter michiganensis subsp.sepedonicus, during the growing season and in progeny tubers after harvest. The highest ELISA values were obtained with the highest concentration of bacteria used to inoculate seed pieces in all cultivars tested. Low ELISA values were obtained for stems and progeny tubers selected from plants grown from seed inoculated at lower bacterial concentrations. Estimates of bacterial densities in stems and progeny tubers by immunofluorescence indicated that low ELISA values were most probably caused by low bacterial numbers. It is suggested that the sensitivity of ELISA for detecting the ring rot pathogen in potato stems and progeny tubers is a function of the concentration of bacteria in individual seed pieces.
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  • 85
    Digitale Medien
    Digitale Medien
    Springer
    Potato research 35 (1992), S. 249-260 
    ISSN: 1871-4528
    Schlagwort(e): bud ; cultivar ; primordium ; Solanum tuberosum L. ; tuber weight
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Potato tuber dormancy is usually defined as lasting from tuber initiation until a sprout of 2 mm long has been formed under storage conditions optimal for sprouting. We tried to find out whether there is a period during which buds of seed tubers do not grow and whether different batches of seed take the same time to grow sprouts 2 mm long. We measured changes in number of leaf primordia and length of tuber buds of cvs Diamant and Désirée over two years. After early haulm pulling, buds did not grow for at least 60 days (‘Diamant’) or 95 days (‘Désirée’). Buds in both cultivars and two tuber weights of ‘Diamant’ took about 20 days from the estimated onset of sprouting to grow 2 mm long. We question whether this period is always similar and thus whether the moment sprouts 2 mm long have formed is a good criterion for the end of dormancy.
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  • 86
    Digitale Medien
    Digitale Medien
    Springer
    Potato research 35 (1992), S. 355-364 
    ISSN: 1871-4528
    Schlagwort(e): cultivar ; nitrate ; nitrogen ; Solanum tuberosum L. ; tuber
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary The duration of dormancy of seed potatoes varies between years and between origins. Therefore, the effects of conditions during crop growth on dormancy of progeny tubers were studied. The effect of nitrogen during tuber bulking on the duration of dormancy was investigated in three field experiments with two cultivars. In addition to an application of 125 kg N/ha at planting, top dressings of 0–150 kg N/ha were given about 2 weeks after tuber initiation. Haulm was pulled about 4 weeks later. The effect of nitrogen rate at planting was also examined in one experiment. Nitrogen top dressings shortened dormancy in all experiments by 5–8 days. An increased nitrogen rate at planting resulted in a shorter dormancy when the duration of dormancy was expressed in days after tuber initiation, but not when it was expressed in days after haulm pulling, probably because extra nitrogen also delayed tuber initiation.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 87
    Digitale Medien
    Digitale Medien
    Springer
    Potato research 35 (1992), S. 55-58 
    ISSN: 1871-4528
    Schlagwort(e): glucose ; fructose ; sucrose ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary A sensitive, rapid and inexpensive method has been developed for quantifying the glucose, fructose and sucrose content of potato tubers. The method, based on selective enzyme-coupled reaction systems and the reduction of NAD to NADH, uses a microplate reader fitted with a 340 nm filter. In one microtiter plate 96 samples can be analysed for all three sugars in less than two hours. Several plates can be processed in parallel.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 88
    ISSN: 1871-4528
    Schlagwort(e): imazalil ; resistance ; black scurf ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Seed tubers, cv. Désirée, derived from stocks treated annually with thiabendazole were infected with thiabendazole-resistant strains ofHelminthosporium solani andPolyscytalum pustulans. Samples of seed tubers were either untreated or immersed for 5 min in fungicide suspensions of thiabendazole, imazalil or thiabendazole plus imazalil and planted on four farms in 1988 and 1989. After harvest, tuber samples from each treatment were treated with thiabendazole and stored for 6 months. Applying imazalil or thiabendazole plus imazalil to seed tubers decreased the severity of silver scurf and skin spot on stored progeny tubers. Thiabendazole applied to seed tubers or to progeny tubers after harvest did not affect the severity of either disease, but post-harvest treatment decreased the incidence of black scurf after storage.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 89
    Digitale Medien
    Digitale Medien
    Springer
    Potato research 35 (1992), S. 41-47 
    ISSN: 1871-4528
    Schlagwort(e): bacteria ; fungi ; herbicides ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Spray application at locally recommended rates of the herbicides thiobencarb and fluchloralin to potatoes reduced the rhizosphere and general soil microbial populations. Within 30 days the populations had generally recovered although there were some changes in the species composition of the fungal community that persisted until the final sample at harvest time.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 90
    ISSN: 1871-4528
    Schlagwort(e): Phytophthora infestans ; Solanum tuberosum L. ; progeny test ; disease screening ; inheritance ; general combining ability
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary TenSolanum tuberosum genotypes differing in resistance to late blight (Phytophthora infestans (Mont.) de Bary) in foliage and tubers were intercrossed to determine the inheritance of disease resistance in their progenies. Plots of 10–15 clones per progeny were established in each of 2 years and resistance assessed by field or laboratory tests. The parental genotypes were similarly tested each year. The parents differed in general combining ability (GCA) for both foliage blight (FB) and tuber blight (TB). The parental and GCA scores were significantly correlated for both aspects of the disease, but the correlations between foliage and tuber scores for parents and for GCAs were not significant. Three parental genotypes were highly resistant in both foliage and tubers, and the genotype with the highest GCA for resistance to both FB and TB (cv. stirling) is recommended as the best parent. There was no evidence of strong genetic correlation between both aspects of resistance, and it is suggested that both be selected for in a breeding programme.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 91
    ISSN: 1871-4528
    Schlagwort(e): ring rot ; Solanum tuberosum L. ; ELISA ; immunofluorescence ; eggplant ; detection
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Potato stems and tubers grown in the field from seed tubers inoculated withClavibacter michiganensis subsp.sepedonicus, which causes bacterial ring rot, were tested by indirect, sandwich enzyme-linked immunosorbent assay (ELISA) in five laboratories. Correlation between values for each experimental treatment from the five laboratories was greater (r=0.86) than correlation between values for individual samples (r=0.71). When three or more laboratories obtained ELISA values of ≥0.200 for a sample, that sample was presumed to be positive. Conversely, when three or more laboratories obtained ELISA values 〈0.200, the consensus determination was regarded as negative. The percentage of stem and tuber samples that were in agreement with the consensus ELISA determination varied from 65.5 to 96.7%. Indirect immunofluorescence tests, conducted on the same samples in two laboratories, were consistent with 83.4–91.9% of the consensus ELISA determinations. Presence or absence ofC.m. sepedonicus was confirmed in some samples by an eggplant bioassay and direct isolatiion of the bacterium. The ELISA procedure was well suited for screening large numbers of samples and this study confirms it to be a promising procedure in routine indexing of seed potatoes forC.m. sepedonicus.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 92
    Digitale Medien
    Digitale Medien
    Springer
    Potato research 35 (1992), S. 389-401 
    ISSN: 1871-4528
    Schlagwort(e): cultivar ; seed tuber ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Four experiments (three with four cultivars, one with twenty cultivars) investigated the effect of different storage temperature regimes on the duration of dormancy of seed potatoes harvested immature. Regimes included constant temperatures (18 and 28°C), hot pre-treatments (20 days at 28°C and subsequently 18°C) and cold pre-treatments (20 days at 2°C and subsequently 18°C). Compared with 18°C, storage at 28°C slightly prolonged dormancy of some cultivars with a genetically short dormancy and shortened dormancy by up to 45 days in cultivars with a long dormancy. Some tubers of one cultivar lost their ability to sprout after storage at 28°C for 90 days. A hot pre-treatment shortened dormancy by 2–3 weeks on average, for all cultivars examined. A cold pre-treatment shortened dormancy by 2 weeks on average in some cultivars with a short dormancy and in all cultivars with a long dormancy.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 93
    Digitale Medien
    Digitale Medien
    Springer
    Potato research 35 (1992), S. 419-432 
    ISSN: 1871-4528
    Schlagwort(e): Solanum tuberosum L. ; seed production ; rapid multiplication ; tuber pruning ; non-destructive harvest ; nutrient supply ; plant density ; plant arrangement
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Minitubers can be produced in large quantities by repeated harvesting of tubers from in vitro propagated plantlets at 4, 7 and 10 weeks after transplanting to the glasshouse at high plant densities. Yield parameters of minitubers can be manipulated by crop husbandry. By supplying nutrients or using a square plant arrangement, minituber yield increased. Effects on numbers of tubers were cultivar-dependent. Changing plant density from 50 to 800 plants per m2 or the minimal diameter of harvested tubers from 5 to 12 mm did not significantly affect tuber yield per m2. Higher plant densities resulted in more tubers per m2 but fewer tubers per plant. Removing smaller tubers greatly increased the number of small tubers, but did not affect yield and number of tubers in larger grades. Crop husbandry techniques affected minituber yield mainly through their effects on leaf area duration, and the number of minitubers through their effects on growth of tubers to a harvestable size.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 94
    Digitale Medien
    Digitale Medien
    Springer
    Potato research 35 (1992), S. 261-269 
    ISSN: 1871-4528
    Schlagwort(e): cultivar ; Solanum tuberosum L. ; tuber weight
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary The variation in duration of dormancy within a seed tuber lot was studied over three years by harvesting individual plants of cvs Diamant and Désirée from field plots and by storing the tubers at 18°C. The variation in dormancy within a tuber lot was large (especially for cv. Diamant) and was mainly caused by variation within plants. For cv. Diamant there was a close negative relation between dormancy and the cube root of tuber weight, whereas for cv. Désirée a relation with tuber weight was almost absent. The duration of dormancy of a seed lot comprising tubers with a narrow range in weight can be well described by two parameters. It is proposed to maintain the moment of 80% sprouting as the criterion for the end of dormancy of a tuber lot and to characterize the spread in dormancy duration by the time lapse between 10% and 90% sprouting.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 95
    Digitale Medien
    Digitale Medien
    Springer
    Potato research 35 (1992), S. 343-354 
    ISSN: 1871-4528
    Schlagwort(e): desprouting ; planting date ; Solanum tuberosum L. ; sprout length ; sprout number ; stem number ; total dry weight ; tuber number
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Young seed tubers of several cultivars were exposed to storage temperatures of 4–24°C in light and dark intended to optimise their growth vigour following early plantings. In five experiments during four autumn and winter periods, the effects of storage conditions on subsequent initial plant development in the glasshouse were studied. Storage of seed potatoes for 2 months at temperatures of 12°C or higher greatly increased early plant development of five cultivars following early plantings. Light during storage had a favourable effect, but desprouting before planting was greatly disadvantageous.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 96
    ISSN: 1871-4528
    Schlagwort(e): seed tuber weight ; relationships ; model ; density ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary The number of stems per seed tuber produced by 17 seed stocks of cv. Record was determined in glasshouse and field experiments to assess the feasibility of predicting the number of stems produced in the field. Multiple regression analysis showed that seed tuber weight alone gave the most satisfactory fit to stems produced in the field, which was not improved by adding terms involving the number of stems produced in the glasshouse. Quadratic relationships between the number of above-ground stems per tuber and tuber weight were most appropriate for each stock, with the fitted curves for individual stocks differing only in the constant term. However, there were significant rank correlation coefficients between the constant terms for relationships between field stems and tuber weight and glasshouse stems and tuber weight, suggesting that in other cultivars and seed stocks a predictive glasshouse test might still be useful.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 97
    Digitale Medien
    Digitale Medien
    Springer
    Potato research 35 (1992), S. 235-247 
    ISSN: 1871-4528
    Schlagwort(e): stem numbers ; tuber numbers ; distribution model ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Tuber samples taken at 2-week intervals from plots of cvs King Edward, Majestic and Pentland Crown in 1964–75 showed that the maximum bulking rates ranged from 1 to 5 tonnes/hectare/week. Maximum tuber numbers were usually produced by 11 weeks after planting and thereafter numbers declined. In September, about 70% of the tubers initiated were recovered, and between 24 and 52% of the tubers had reached marketable size (〉4 cm). Tuber size distributions developed similarly in all years with all cultivars. During tuber initiation the distributions appeared as one population, and usually between 9 and 11 weeks after planting a second population of larger tubers developed. The population of small tubers later declined although in most years it was still present in September. This development fitted a model based on a mixture of two normal distributions and was determined by five parameters; the proportion of tubers in the small population and the means and standard errors of both populations.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 98
    Digitale Medien
    Digitale Medien
    Springer
    Potato research 35 (1992), S. 271-277 
    ISSN: 1871-4528
    Schlagwort(e): Erwinia chrysanthemi ; resistance bacteria ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Calcium levels in the periderm of tubers (cv. Sebago) growing in irrigated sands were influenced by the stem position at which the tuber grew, but the effect was not consistent over two seasons. Calcium levels were increased at all tuber positions by addition of calcium to soil; combined treatments of gypsum (1400 kg Ca2+/ha) pre-plant and calcium nitrate (37 kg Ca2+/ha) side dressings gave the greatest response. Percentage incidence of soft rot lesions caused byErwinia chrysanthemi pv.zeae was not influenced by periderm calcium content. The severity of infection (weight of tissue macerated within 48 h at 30°C) was significantly reduced only by the pre-plant gypsum treatment, but there was no correlation with calcium content of the periderm. Calcium levels in periderm tissue (60–208 mg Ca2+/100g) are within the range of published data for other cultivars and results support previous reports that the correlation between tuber susceptibility toErwinia spp. and periderm calcium content is inconsistent.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 99
    Digitale Medien
    Digitale Medien
    Springer
    Potato research 35 (1992), S. 365-375 
    ISSN: 1871-4528
    Schlagwort(e): cultivar ; heat sprouting ; nitrogen ; second growth ; Solanum tuberosum L. ; sprout ; tuber
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary In two indoor experiments under short day conditions, the effect of temperature during tuber bulking on dormancy of tubers was investigated for cvs Diamant and Désirée. Temperature treatments started after tuber initiation and lasted for 4 weeks, after which the haulm was removed. In Experiment 1, the day/night temperature regimes 18/12, 22/22, 26/18 and 32/12 °C (T18/12 etc.) were compared. In Experiment 2, three day temperatures (18, 24 and 30 °C) were combined with three night temperatures (12, 18 and 24 °C), resulting in nine treatments. The dormancy of cv. Diamant was shortest after very high day temperatures (30–32 °C), but intermediate day temperatures (22–26 °C) had no shortening effect compared to T18/12. Dormancy of cv. Désirée was not shortened, but rather tended to be prolonged by high temperatures (22–32 °C) during growth. High temperatures during growth resulted in more sprouts per tuber after dormancy had ended.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 100
    Digitale Medien
    Digitale Medien
    Springer
    Potato research 35 (1992), S. 133-142 
    ISSN: 1871-4528
    Schlagwort(e): Corynebacterium sepedonicum ; dwarf-rosetting ; Solanum tuberosum L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Plants were grown in the field from seed pieces of potato cultivars injected with ring rot bacteria (Corynebacterium sepedonicum). Symptoms were produced with both 18 and 180 colony forming units (cfu) on cvs Norchip and Red Pontiac and with 180 cfu on cv. Belrus plants. Tuber symptoms were detected in all cultivars except Belrus and Teton. Tuber progeny produced plants that developed top symptoms on all cultivars except those of cv. Nooksack, Russet Burbank, and Teton. Tuber progeny of the second crop produced both plants and tubers with symptoms developing only in the cv. Nooksack. In another 3-year experiment, variability in the disease response of selected cultivars and lines was examined following knife-inoculation of tuber seed with a high level of ring rot bacteria. Significant correlations between top and tuber symptoms were detected, but they were not high enough to make unnecessary the examination of both top and tuber symptoms in ring rot disease selection studies.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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