ALBERT

Notes: Elimination of shooly larvae increased grass yields daring the September feeding period. Increases were usually less than 10% bat in one case, where growth was abnormally slow, die increase was over 30% and in another, where the larval population was atypically dense, it was almost 60%. The effects of damage were not cumulative daring the feeding period; and at the end of this period insecticidreated plots sometimes gave lower yields than untreated plots. Fertilizer increases had a much greater effect on yield than did control of larvae and, where N was applied at 75 kg/ha (67 lb/ac) in spring, the additional effect of larval control was usually negligible. It is suggested that shoot-fly damage may be more serious in other localities.When turf containing shoot-fly larvae was ploughed, Oscinella spp. re-established themselves more successfully than others in seedling ryegrass bat did not damage the new sward appreciably.

Notes: The drying of small herbage samples should be as rapid as possible so as to limit respiratory loss and enzymatic interconversions, especially if certain nonstnictnral carbohydrates are to be assayed. An inexpensive thermo-switch is described that indicates the time required to heat a mass of tissue in an oven to a given temperature. The time required to heat green herbage to a temperature (55°C) that will inactivate respiratory enzymes can be determined.

Notes: A linear programming model of a high-temperature grass-drying enterprise is described. From information about seasonal crop response, area of crop available and management constraints, the model determines the harvesting schedules which give greatest returns, less costs, from the enterprise over the season. This information can be used to examine the effects of long-term strategic decisions or to evaluate economically data on new crops from field experiments. For example, assuming a fixed cost of λ70,000/year for a high-temperature grass-drying installation and what is considered to be reliable input data for 1972, the returns less costs for optimum harvest schedules from different areas or crop varieties are:〈table colsep="0" rowsep="0" frame="topbot" pgwide="1" orient="port"〉〈tgroup cols="5" align="left"〉〈colspec colnum="1" colname="col1" align="center"/〉〈colspec colnum="2" colname="col2" align="center"/〉〈colspec colnum="3" colname="col3" align="center"/〉〈colspec colnum="4" colname="col4" align="center"/〉〈colspec colnum="5" colname="col5" align="center"/〉〈thead valign="bottom"〉〈entry namest="col1" nameend="col2" align="left"〉Corp areaSurplusGrass ac (ha)Lucerne ac (ha)Return, £Less costs £/ac(£/ha)crop ac (ha)〈tbody valign="top"〉800(324)0(0)42,849536(132.3)0(0)1000(405)0(0)60,286603(1489)205(83)600(243)200(81)46,73158.4(1442)0(0)800(324)200(81)65.66165.7(1621)109(44) The model can also provide information con cerning tbe limitations imposed by equipment stage of tbe process and management re straints sucb as limitations on overtime and shut downs for holidays or maintenance.

Notes: Newly-sown S24 perennial ryegrass at Hurley and old established ryegrass-dominant mixed pasture at Rothamsted were treated with several pesticides, singly and in combination, over the period 1969–73. Yields were either unaffected or increased by up to 30% in any one year, depending on the treatment, the newly-sown sward giving the more consistent response from year to year.

Notes: The DM production from INRA 200, an early maturing hybrid maize grown for silage, was 10±6 and 14 5 t/ha in mid-October 1972 and 1973 (4±2 and 5±8 tons/ac). The plant population in both years was approximately 112,000/ha (45,320/ac). Whole-crop and cob DM percentages were 18±2 and 21±3 for 1972 and 39±9 and 53±0 for 1973, respectively. The cob yields were 49 and 10±4 t/ha (2±0 and 4±1 tons/ac) in 1972 and 1973 and cob in the two years accounted for 46 and 72% of total yield. At harvest the 1973 crop was 4–6 weeks more mature than the 1972 crop. These differences were attributed to the difference in accumulated temperature recorded from May till October, which was 567°C days in 1972 and 817 in 1973. Whole-crop DM content, yield of cob and yield of cob as a percentage of total yield were studied against seasonal temperature accumulation. In the case of DM percentage there was a highly significant linear regression which showed that 627°C days were needed to mature maize to 24% DM content.

Notes: Experiments were carried out with different depths of added topsoil, with different methods of cultivation and with different rates of application of fertilizers on an ash disposal site near Newark. Good yields of hay and wheat were obtained and were shown to vary systematically with the treatment of the plots. Good yields of wheat were obtained with a top dressing of 125 kg N/ha even on bare ash but, in contrast with the yields of DM from grass, yields of grain tended to increase with increasing depth of added soil. This pattern appeared to be influenced by the variations in spring rainfall. There appeared to be no adverse effects of uptake of trace elements from the ash.

Notes: The DM and N contribution of S184 white clover in mixed ryegrass/clover swards was recorded at Pant-y-dwr Hill Centre (305 m) for 4 years, 1967–70. By direct comparison with fertilized grass swards it was estimated that the clover N contribution on peaty gley soil averaged 100 kg N/ha per year (89 Ib N/ac) under cutting and 98 kg N/ha (87 ib/ac) under grazing with faecal return. On more fertile acid brown earth the corresponding contributions were 81 and 90 kg N/ha (72 and 80 Ib/ac). Full replacement of clover by N fertilizer would require average annual applications of 268, 229, 156 and 128 kg fertilizer N/ha, respectively (239, 204, 139 and 114 Ib N/ac).

Notes: Book reviewed in this article:EYRE, S. R. (Editor) World vegetation types.SCHMIDT, W.; WETTERAU, H.; BEYRICH, H.; MÜLLER, M.; GOTTSCHLING, E.-M. [Silage production.] Silageherstellung.LAMBRECHTSEN, N. C. What grass is that? A guide to identification of some introduced grasses in New Zealand by vegetative characters.LEIGH, J. H.; NOBLE, J. C. (Editors) Plants for sheep in Australia.THURM, R. [Technology of agricultural production.] Technologie der landwirtschaftlichen Produktion.TAYLOR, S. A.; ASHCROFT, G. L. Physical edaphology. The physics of irrigated and nonirrigated soils.DAVIES, D. B.; EAGLE, D. J.; FINNEY, J. B. Soil management. Ipswich, Suffolk, UK, Farming Press Limited.OLSON, R. A.; ARMY, T. J.; HANWAY, J. J.; KILMER, V. J. (Editors) Fertilizer technology & use.PAPADAKIS, J. Auxins, biochemical plant interaction, growth retardants and dense high yielding crops. Córdoba, Argentina, J. Papadakis.

Notes: An electronic pasture-meter was found to be of limited use for the routine estimation of DM production of oat cultivars for the reason that the relationship between the meter reading and DM varied with different cultivars.

Notes: The duration of the juvenile phase in early-flowering (Dorset Marl) and late-flowering (S123) red clover is described. Neither cultivar responded to inductive conditions at the first leaf stage but Dorset Marl attained maximum sensitivity by the 3-leaf stage. A comparable response was obtained with S123 only after the production of 12–13 leaves. The growth characteristics of the two types under continuous long or short days are described and possible explanations are advanced for the characteristic differences in tillering and stem internode number.

Notes: For three weeks after emergence, micro-swards of Lolium rigidum were defoliated to a height and at a frequency which represented a range of set stocking rates of less than, similar to, and more than 7–8 sheep/ha as based on the results of Greenwood and Arnold (6) and referred to as D1, D2 and D3 respectively. The effects of these defoliation regimes on the growth and development of emergent swards were evaluated according to their effect on increments of DM from plant parts, rate of appearance of leaves and tillers, concentration of soluble carbohydrates, and on the uptake and concentration of inorganic nutrients.Defoliation began five days after emergence, when the dry weight of the shoot was 3g/m2. After 20 days of treatment, 6±7 g/m2 of DM had been removed from D1, 5±5 g/m2 from D2 and 51 g/m2 from D3; and the dry weight of shoot remaining was 13, 7 and 4±5 g/m2 on D1, D2 and D3 respectively. The effect of defoliation on dry weight of plant parts increased in severity in the order leaf 1, stem+sheaths, leaf 2, roots, leaf 3, tiller 1, tiller 2, leaf 4. Average relative growth rate of the sward was reduced from 17% per day on D1 to 13% per day on D3. There was no necrosis of root tissue. Emergence of the later leaves and of the tillers was retarded by up to three days by more frequent defoliation. Alcohol-soluble carbohydrates in the root fell from over 6% to about 1±5% on all treatments. Uptake of N. P and K was limited by increasing intensity of defoliation and because concentrations of those elements were not greatly affected, the limitation could be ascribed mainly to the effects of defoliation on plant size.The plausibility of the technique for the experimental simulation of grazing of emergent annual grass swards in Western Australia is discussed. It is concluded that for set-stocking rates of less than about 12 sheep/ha, grazing, while reducing DM production just after emergence, is unlikely to produce severe physiological stresses in the sward.

Notes: The uptake of N was measured in 2 successive regrowths harvested on 12 June and 13 Aug. following harvests of primary growths 8, 12, 16, 23, 29, 45 and 57 (12 June) days after applying N at 59, 118 or 177 kg N/ha on 16 Apr.Residual responses were obtained to both increments of N, leading to high apparent recoveries of fertilizer N, especially to the higher increment. This increased availability of soil N when high rates of N are applied is shown to vary with date of harvest of primary growth, reaching a maximum equivalent to 151% apparent fertilizer N recovery 23 days after N application.In the second regrowth, percentage N in the herbage showed a negative response to N applied to the primary growth. This appears to reflect a reduction in available soil N brought about by its increased availability and uptake in primary growth and first regrowth.The possibilities of improving the efficiency of fertilizer N by exploiting soil N are considered against the possible reduction in available N for future regrowths.

Notes: In the management of British grassland lay there appears to be a marked divergence between the policies advocated by grassland science and general grassland practice. While science places emphasis on monocultures of sown species (mainly perennial ryegrass), heavily fertilized and intensively stocked, grassland farmers for the most part rely on lonstablished or indigenous swards composed of a variety of species and receiving modest applications of fertilizer. Since the gap between the two approaches is both substantial and of long duration the subject appears to be worth fresh attention. The purpose of this paper is to examine the current situation in relation to improvement in botanical composition and to suggest new approaches to that end.

Notes: The last 10 years have seen a marked shift in Britain from the growing of legumes towards the use of fertilizer N. Many farmers are now reassessing the position Decause of increasing fertilizer prices and because of improvements in clovers and lucerne through plant breeding.On the intensive dairy farm legumes can play an important part in the conseravation block. The yield of lucerne without applied N is as high as from ryegrass with 250 units N/ac. Red clover is also useful over a wide range of soil types.On the less intensive farm, white clover should be contributing throughout the grazing area. there are many reasons for poor white clover populations in pastures; one of these is the fungus disease Sclerotinia trifoliorum, commonly known as clover rot. Varieties resistant to this disease are available in both red and white-clover. Verticillium wilt in lucerne bas also been checked by the plant breeder.Improved legume varieties justify a completely new look at these crops and the possibilities for lucerne in this country appear to be particularly good.

Notes: Irrigated plots of a mixed sward of Lolium perenne, Paspalum dilatatum, Bromus unioloides, Dactylis glomerata and Trifolium repens were used in 2 experiments during 4 years. In the first experiment, die treatments comprised factorial combinations of heights of cutting of 3, 6 and 10 cm (1.2, 2.4 and 3.9 in.) above ground level, and heights of growth of 5, 13 and 20 cm (20, 5.1 and 8.0 in.) above the height of cutting. In the second experiment, 8 combinations of dose (3 cm or 1.2 in.) or lax (10 cm or 3.9 in.) cutting were applied at various times during each year.In the first experiment, DM production for cutting heights of 3, 6 and 10 cm was 50, 44 and 43 t/ha (198,17.5 and 171 ton/ac), respectively; the DOM production was 37, 32 and 32 t/ha (147, 12.7 and 12.7 ton/ac). DM production for growth heights of 5, 13 and 20 cm was 45, 46 and 48 t/ha (17.9, 183 and 191 ton/ac), respectively. DOM production, 34 t/ha (13.5 ton/ac), was not affected by height of growth.Percentages of protein (26, 22 and 20) and DOM (76, 72 and 71) declined as the height of growth was increased; but cutting height produced no significant effects in them. As cutting height was increased the percentage of clover declined (40, 31 and 23) and that of grasses increased (52, 66 and 72); diere were smaller changes with changes in height of growth.Hie second experiment showed that the difference between close and lax cutting became significant only when lax cutting was applied for at least half of the cuts each year. DM production was similar for treatments witii the same number of close or lax cuts, regardless of the time of year at which the two heights of cutting were applied.

Notes: The effect of increasing annual fertilizer N application rate from 400 to 800 kg/ha (357 to 714 lb N/ac) and stocking rate from 5.0 to 7.5 animals per forage ha (2.02 to 3.04 animals per forage ac) on herbage availability, digestible OM intake and live weight gain was investigated in a grazing experiment repeated in 3 consecutive years. A 21×1 day rotational paddock grazing system was used in which the grazing area was increased in the ratio of 1:1.5:3 on two predetermined occasions.Increasing the fertilizer N application rate increased herbage availability by 12% but failed to increase live weight gain. Increasing stocking rate decreased herbage availability per ha and per animal, and also live weight gain per animal, but increased live weight gain per forage ha by 17.6%.

Notes: A model is described which can be used to synthesize dairy systems under various price environments and sets of decision rules.The potential use of the model is illustrated with reference to the seasonal calving pattern as an economic decision.

Notes: Different grazing treatments applied to pastures in which perennial ryegrass was dominant had little influence on DM production during the main reproductive growth period in late spring and early summer. Lax and infrequent grazing at this time did, however, reduce tiller density. During the dry summer period lax infrequent grazing increased production by 20%, while in the vegetative growth period in autumn those pastures which were alternately lax- and hard-grazed outyielded those which were hard grazed by 63%.In all treatments, initial recovery growth resulted almost exclusively from the production of leaf tissue. The rate of leaf growth declined three to five weeks after grazing, depending on treatment and season, and subsequent yield increase was dominated by sheath and stem growth.

Notes: The liveweight gain was measured of beef cattle on pastures stocked at 5.9 to 11.8 cattle/ha and receiving 50, 182 or 329 kg N/ha in a 12-week season. N levels and stocking rates were so adjusted that similar yields of herbage per animal were expected. Results showed that similar liveweight gains per animal, averaging 1.03 kg/day, occurred at all N levels. Liveweight gain/ha ranged from 547 to 1037 kg in 12 weeks and the corresponding quantities of metabolizable energy utilized were 9890 and 17590 Meal. The results confinn earlier work (4, 7).

Notes: Three cutting heights, 2±5, 7±6 and 12±7 cm (1, 2±5 and 5 in.) and three levels of fertilizer N, 168, 280 and 392 kg N/ha (150, 250 and 350 Ib N/ac) were imposed on a sward of Italian ryegrass (Lolium multiflorum) cv. Irish. Lowering the cutting height and increasing the level of applied N increased the yield of herhage DM. Increasing the level of applied N had a greater effect on the chemical composition of the herbage than altering the cutting height

Notes: Six perennial ryegrass varieties which were known to differ in winter hardiness were subjected to ten managements comprising two N rates and fire autumn cutting treatments. Autumn yields and soluble carbohydrate contents were measured, also the amount of winter damage in February and subsequent spring yields.The winter was mild, herbage damage was slight and no plant deaths were recorded, but significant differences were found between cutting treatments and varieties. The amount of winter damage increased with the length of the autumn rest period and with the degree of winter dormancy of individual varieties, indicating that natural senescence was a more important causative agent than frost action. Spring yields were affected by the amount of winter damage but there were considerable interactions between varieties and environments.The results are discussed in relation to autumn management practices, choice of variety for different locations and measurements of winter hardiness. The induction of winter dormancy by day length or low temperature reactions is considered in the breeding of varieties for maximum production in different parts of the country.

Notes: Two experiments, each of 6 weeks dehydration, were conducted in 1972. In Expt 1, 24 cattle were grazed in individnal paddocks during July and August and received one of 4 treatments over a 6-weeks period: no supplements; straw ad lib; 3.3 kgj. day sugar-beet pulp; 4.0 kg/day molasses. Mean daily live weight gains were significantly increased by the sugar-beet pulp and molasses supplements; which also increased OM and DOM intake significantly. The increase in total OM intake per kg OM in the supplement was 0.48 for sugar-beet pulp and 0.67 for molasses.In Expt 2, 18 cattle grazed in groups of 3 during November and December. Two groups each received 0.5, 3.5 or 6.5 kg/day sugar-beet pulp over a 6–weeks period. There was no significant difference in live weight gain between treatments, and no significant difference in total intake. Intake from pasture declined with increasing level of supplement, so that the average increase in OM intake per kg OM in the supplement was 0.28.Hie results are discussed in relation to availability of pasture and the effects of the supplements on intake.

Notes: Book reviewed in this article:GARNER, F. H. (Editor) Modem British fanning systems.HANSON, C. H. (Editor) Alfalfa science and technology.GIMINGHAM, C. H. Ecology of heathlands.FUSSELL, G. E. Farming technique from prehistoric to modern times.DURING, C. Fertilizers and soils in New Zealand fanning.KOSTROWICKJ, J.; SZCZESNY, R. Polish agriculture.ODINGO, R. S. The Kenya Highlands. Land use and agricultural deTelopment.

Notes: Irrigated plots of a mixed sward of four grasses and white clover were cut to a height of 3 cm in either June, August, October, December or February. The plots cut at each commencement date were harvested when the height of growth of the pasture was either 10, 18, 25, 32, 40, 48 or 55 cm. At each harvest, the pasture was cut at 7 to 8 cm intervals down to a height of 3 cm. DM production, botanical composition, in vitro digestibility (DOM) and CP of each layer was determined.DM production declined from the lower to the upper layers for pastures shorter than 32 cm. For pastures taller than 32 cm, DM production declined from the lower to the middle layers, then increased in the upper layers, due mainly to the presence of seed heads.Maximum percentages of DOM and CP were observed for the middle layers of the pastures taller than 25 cm. For pastures shorter than 25 cm, DOM and CP percentages increased from the lower to the upper layers, for all commencement dates. The percentages of DOM and CP of each layer decreased as the height of growth increased.The percentage of DOM showed a positive correlation with the percentages of Lolium perenne, Bromus unioloides and Trifolium repens, and a negative correlation with the percentages of Paspalum dilatatum and chlorotic material. The percentage of CP showed a positive correlation with the percentages of Paspalum dilatatum, Dactylis glomerata and Trifolium repens and a negative correlation with the percentages of chlorotic material and the total of the four grasses within the pasture layers.The lower layers of the pasture produced large quantities of DM and, despite the lower in vitro digestibility of these layers, they produced more DOM than the other pasture layers. The DOM production of the pasture increased with increasing height of growth, but decreased as the commencement date was altered from winter through to the end of summer.

Notes: Data are presented demonstrating the effects of applying fertilizer N at 59, 118 or 177 kg/ha on 16 Apr. on uptake of K, P. Ca, Mg and Na in primary growth (PG) harvested 8, 12, 16, 23, 29, 45 and 57 days afterwards, and residual effects in two successive regrowths (RG1 and RG2) harvested on 12 June and 13 Aug., respectively.Significant residual responses as uptake of K, P, Ca, Mg and Na were shown in RG1 and RG2 after all dates of harvesting PG. The residual responses compensated for poor uptake in PG. Thus, low uptakes to the second increment of N were followed by high residual responses in both regrowths; and low uptakes in PG harvested shortly after applying the fertilizer N were followed by high residual responses.Averaged over the seven dates of PG harvest, the sum of responses (PG+RG1+RG2) to the second N increment was greater than total response to the first increment in P and Mg, considerably greater in Ca and Na and slightly lower in K. These marked residual responses to the second N increment were most noticeable where PG was harvested 23 days after applying fertilizer N and became less marked as date of PG harvest was advanced.Percentage K, P, Ca, Mg and Na in DM of the PG and of RG1 increased as N application was raised. By RG2, the residual effects of fertilizer N on percentage K. P and Mg were reversed to give reduced percentages with increased N application to PG. indicative of deficiencies in availability of these elements.The application of 177 kg N/ha to PG resulted in the release of additional soil N and of other mineral elements which could lead to their depletion.

Notes: An experiment was conducted in 1971 and 1972 to study the effects of two levels of fertilizer N (50 and 504 kg/ha) on the productivity of pastures grazed by young beef cattle. Two stocking rates were imposed at the lower N level and three at the higher. In addition to rotational grazing, set-stocking and an integrated grazing-conservation system were included. The responses/kg N were approximately 1 kg live-weight gain, 19–24 Meal ME and 8–9 kg DM. Maximum yields of 1200–1300 kg live-weight gain/ha and 25,000–27,000 Meal ME/ha were recorded. Productivity of set-stocked pasture was similar to rotational grazing at the high N level, but lower at low N. The integrated system yielded comparable results to high-N rotational grazing. Performances and herbage intakes per animal reflected the stocking rates imposed.

Notes: An experiment designed to compare the nutritive values for milk production of dried grasses harvested in spring and autumn is described. The DM digestibility of the spring- and autumn-dried grass was 67±7 and 66±0%, respectively. Both dried grasses were fed at two levels, 0±4 and 0±5 kg/ kg milk (4 and 5 Ib/10 Ib milk), to lactating cows in a randomized-block design experiment using 24 animals. Each animal was also given 2±5 kg hay/day (5±5 Ib) and in addition sufficient of the dried grass under investigation to meet maintenance requirements.Milk yield, milk energy output, live-weight gain and the solids not fat (SNF) and protein contents of the milk increased with feeding level. Season of dried grass harvesting had no effect on milk yield, milk energy output or live-weight change. The spring-harvested dried grass resulted in a significantly higher milk SNF content than the autumn-dried grass and also tended to reduce milk butterfat level.

Notes: The grass intake of three breeds of ewe was measured in the 5th–7th week (Period 1) and the 9th–11th week (Period 2) of lactation. The breeds of ewe were Finnish Landrace × Scottish Halfbred (FH), Finnish Landrace × Scottish Blackface (FB) and Thornber Colburn Colbred × Scottish Blackface (TC2). The immature FH ewes had a lower intake of digestible OM (26±1g/kg LW per day) than the mature FB (32±2g/kg LW per day) and TC2 ewes (33±5g/kg LW per day) in Period 1, but there were no difference between the breeds in Period 2. The intakes in Period 2 were significantly lower than those in Period 1.

Notes: The relative uptake of P was measured in two varieties of Lolium perenne using radioactive tracer techniques. The diploid cv. Hora and the tetraploid cv. Terhoy were sown as pure stands and as 50:50 mixtures at both high and low density. Uptake from four depths 10, 20, 30 and 40 cm was examined. The results showed that: in pure stands the diploid uptake at 10 cm exceeded that of the tetraploid although at deeper levels the uptake pattern was similar; in mixtures the uptake of the tetraploid variety increased markedly at 10 cm while that of the diploid variety decreased. The diploid compensated for its decreased uptake at 10 cm by a substantial increase in uptake at 20 cm; overall the tetraploid variety had a deeper pattern of uptake than the diploid; in general, uptake at high density was greater than that at low density; the mixture showed a greater degree of P utilization than pure stands in the upper layers of the soil; when these two varieties are grown together in 50:50 mixtures the tetraploid is relatively more efficient in taking up.

Notes: The results are reported of the effects of fertilizer and grazing or cutting for hay over a period of 6 years on the composition of an Agrostis/Festuca permanent pasture on low-lying land at Beghroke Hill. Applications of N up to 264 units/ac each year associated with frequent defoliation every 21 days produced only small changes in sward composition; Agrostis spp. declined and Poa trivialis increased. Lolium perenne did not increase from a small initial presence. Records of animal performance and hay yield showed that the mean output from the experiment as a whole was 530 Ib liveweight gain/ac and 0·5 ton hay/ac.

Notes: The cathepsins in saline muscle extracts of three species of Pacific sole were investigated. A buffered hemoglobin solution (pH 3.0) served as substrate for the enzyme assay. No apparent change in catheptic activity in muscle homogenates of English sole was observed during 25 days of frozen (−26 °C) storage. Partial characterization of the cathepsins indicated a pH activity optimum of 3.0–3.5 for rex and petrale sole but a slightly higher PH optimum of 3.2–3.8 for English sole. The three species showed a temperature optimum of 45 °C for hemoglobin splitting. A wide variation in catheptic activity within the species was observed for rex sole while English and petrale sole showed more uniform catheptic activity. The mean activities for the three species varied significantly (P 〈 0.05). Results of sensory evaluation of muscles containing high and low levels of catheptic activity from the three species of sole did not support the assumption that cathepsins have a substantial influence upon the quality of marine food fish.

Notes: Studies have indicated that one factor responsible for protein-calorie malnutrition in children is the deficiency of good-quality protein and calories in their habitual diets. Previous investigations attempted to solve the problem by means of supplementation with good-quality protein, but this research has not considered direct correction of the calorie deficit. Thus studies were carried out to improve both the protein quality and calorie content with a single food: soybean, added and processed together with maize. Two types of food preparations were studied: tortillas made from 85% maize and 15% whole soybeans (processed together by the lime-cooking treatment used for maize) which when compared to the usual one, had a higher protein and calorie content, and was very acceptable in both appearance and taste. Higher levels of soybean mixed with maize were also tested to develop food preparations with higher concentrations of both calories and protein. These were also processed by the lime-cooking treatment. From these tests a mixture of soybean and maize in the proportion 28g soybean to 72g maize gave a food preparation with 18% protein, 10% fat and a high-protein quality as measured by its PER. The use of higher soybean levels did not improve protein quality, and the yields of the resultant products decreased.

Notes: Breads in which water and milk powder were replaced with unrefined pork blood and/or cottage cheese whey were compared with commercial white bread and an “organic” whole wheat bread. Loaves were evaluated for appearance, composition and acceptance. Rat feeding studies in which the breads contributed about 10% protein to otherwise complete diets indicated no significant differences in growth performance (adjusted PER's) between commercial and “organic” bread. Significantly better performance was obtained for loaves containing blood, whey and blood: whey mixtures. The experimental loaves were comparable in acceptability to commercial breads, although loaf volumes were much lower and crumb texture coarser.

Notes: Minced fish muscle recovered by flesh separators may vary in bone particle content depending on the type of machine and the size of the openings that the fish are passed through to screen out the skin and bones. Orderly marketing of these materials will require some measure of control of the bone particle content. The method presented here for quantifying the bone particle content of minced flesh by gravity-flotation involves (1) shredding the flesh with a low-speed stirring device and (2) gravity separation of the bone, cartilage and other high-density components from the lower-density floatable muscle fibers. Experimental samples obtained by passing various fish materials through flesh separators and then through 1- and 2-mm flesh strainers were analyzed for their bone particle content by the proposed method. The bone particle content of flesh containing 25 to more than 100 particles per pound could be reduced by 70–100% by passage through strainers. Imported commercial samples displayed bone particle contents of 4 to over 400 per pound. Sensory panels could not detect more than 10% of the particles found by objective analysis. The gravity-flotation method may serve as a useful quality control tool.

Notes: Loigo species of squid was investigated as a potential source of protein isolate. The various process parameters which influence extraction of protein (particle size, time, extraction pH, salt concentration, relative amount of solvent to squid tissue and temperature) were investigated. From this study the following parameters were chosen to optimize extraction: pH 11 (sodium hydroxide) or 4% salt concentration (sodium chloride, sodium hexametaphosphate in aqueous extractant); temperature = 22°C; time = 45 min; particle diameter = 2–3 mm; solvent-to-squid ratio = 10:1. Under these conditions, about 85% of the squid protein can be extracted. 65% of the extracted nitrogen is recovered as protein isolate by isoelectric precipitation at pH 5.

Notes: The effects of air velocity, relative humidity, temperature and presence of glucono delta lactone (GDL) on the quality of frankfurters, were evaluated. Rate of heating was inversely proportional to rate of weight loss during processing. High humidity processes at slow air flows had the fastest heating rates; however, quality was unacceptable because of fat separation and pale color. A process where the smokehouse temperature was slowly increased by 6°C increments, and where a low relative humidity and high air flow were used, gave the best quality. Color and texture was more desirable on products having higher shrink. The presence of GDL had no effect on the final color of products processed under the same conditions; however, maximum color appeared to develop earlier in samples containing GDL.

Notes: The effect of temperature and smoking schedules on the quality of Spanish mackerel was evaluated using a pilot plant model of a commercial smokehouse system. Although the final moisture contents of the products are the same, the product smoked only at high temperature (160°F) had the softest texture. Smoking only at low temperature (100°F) did not develop surface color thus resulting in a product having the poorest appearance. A process which combined smoking at both low and high temperature at 60% RH gave a product having excellent texture and appearance. High temperature smoking above 160°F darkened the surface excessively and reduced product acceptability. A holding period after brining and between the cold and hot smoking stages in the process improved appearance and smoke flavor. Water phase salt content judged to be the optimum saltiness was 3.7%. Microbiological counts in the product of the combination cold and hot smoking process were very low (〈 10/g). Smoking at 90–100°F did not allow an increase in surface microbiological count. The final step in the process when carried out at 160°F inactivated most of the vegetative microorganisms inoculated on the surface. Storage life of Spanish mackerel produced by cold followed by hot smoking (160°F) was 45 days at 38°F and at least 22 wk at 10°F. This process does not meet the 30 min at 180°F minimum temperature requirement in the Good Manufacturing Practice Regulation of the Food and Drug Administration for smoked fish; therefore, frozen storage and distribution are recommended.

Notes: The effect of nitrite and storage temperature and toxinogenesis by Clostridium botulinum in vacuum-packed side bacon was investigated. In two series of experiments (A & B) bacon packs were prepared with levels of 0, 50, 100, 150 and 200 ppm nitrite and inoculated with C botulinum at 102 spores/g and 104 spores/g. Packs A were incubated at 20 and 30° C and packs B at 30°C only. Both were held for a maximum of 32 days and analyzed for toxin at intervals of 2, 4, 8, 16 and 32 days. At 20°C none of the controls without nitrite was found to be toxic after 32 days. At 30°C inhibition of toxin formation at the higher nitrite levels was observed at 32 days. Organoleptic evaluation of the bacon packs stored at 30° C showed about one-third of the toxic samples examined were acceptable to the panel.

Notes: Each of three ground beef products, varying in price (based on lipid content) were purchased from each of three retail stores. Patties of each product were modified broiled at 177°C for 35 min. Products containing 10–20% lipid had less cooking loss than those containing 25–30% lipid, but lower-lipid, higher-priced beef cost more per 100g of cooked meat than higher-lipid, lower-priced beef. Percentage ether extract decreased after broiling raw ground beef containing 20–30% lipid, and increased slightly after broiling raw ground beef containing less than 12% lipid. Over-all acceptability was similar for all three products, but the leanest, highest-priced product rated less juicy, more mealy and lower in flavor than higher-lipid, lower-priced products.

Notes: 96 hams (48 left and right pairs) were assigned to either accelerated or conventional processing methods following separation from their respective sides at a commercial slaughter plant. Bacteriological survey samples were aseptically removed from the accelerated and the conventionally processed hams prior to curing. A second bacteriological sample was removed from both the rapid and conventional treatments following curing, smoking and chilling. Total bacterial counts were then determined on both the fresh and cured muscle tissue. The effect of different processing techniques was evaluated by bacterial flora present in the rapid and conventionally processed hams. Aerobic bacteria (15°C and 37°C) anaerobic bacteria (37°C) and anaerobic sporeformers were analyzed statistically. Anaerobic sporeformers were estimated by the most probable number method. No significant differences (P 〈 0.01) were found between rapid or conventional processing techniques in total aerobes and anaerobic sporeformers in fresh or cured muscle tissue. Total anaerobes were significnatly greater (P 〈 0.05) in conventional processing when compared to rapid processing. Results reveal no significant bacteriological problems in the rapid processing of pork prior to initial chilling.

Notes: The combined effects of freezing rate, frozen storage and reconstitution method on meat quality and yield were studied in multifactorial experiments using pan-fried 1.5 cm slices of longissimus muscles and deep-fat fried meat patties. On the whole, a slight improvement in sensory quality and yield was seen with increasing freezing rate, except that liquid nitrogen immersion freezing influenced flavor negatively. In contrast with earlier results of ours with raw beef, an advantage was now seen for reconstitution after previous thawing over reheating directly from the frozen state, and pan frying gave better sensory quality but lower yield than continuous microwave reheating. Tenderness of sliced, cooked beef tended to increase during frozen storage, while the opposite was earlier observed for frozen raw beef. Otherwise, a general trend was seen towards decreasing yield and sensory quality during frozen storage. A number of significant interactions between variables was obtained, suggesting that their influence on quality and yield is interrelated in a rather complex manner.

Notes: A study is made to develop a tool to predict drying performance of nonconventional shapes. Many food drying processes are diffusion-controlled. An approximated analytical solution to Fick's diffusion equation is given for bodies which have a cardioidal, corrugated, circular, epitrochoidal, square, or hexagonal cross section. A conformal mapping approach is used to obtain the concentration distribution and the result is integrated over the volume to yield analytical weight loss equations for each shape. The result is applied to compare drying performance of apples on an equal weight-equal cross sectional area or an equal weight-equal thickness basis.

Notes: Mutton carcasses and lamb carcass cuts were mechanically deboned at different settings to give variable yields of mechanically deboned meat. Higher yields of mechanically deboned meat were related to higher calcium and fat percentages. Lamb breasts had the lowest bone percentage of any of the cuts and the mechanically deboned meat from breasts had the lowest calcium content when compared to deboned meat from other lamb cuts or mutton carcasses. Necks had the highest bone percentage and the highest calcium content in the mechanically deboned meat. Data are presented which show that mechanically deboned meat is not homogenous as it is extruded from the cylinder. Palatability of bologna made with mechanically deboned meat increased as the size of cylinder holes through which the meat was extruded decreased.

Notes: The amounts of total and individual fatty acids present in tri-glycerides (TG), free fatty acids (FFA), diglycerides (DG), monoglycerides (MG) and polar lipids (PL) were determined at various stages of dry sausage ripening using a combination of thin layer and gas chromatography. Total FFA increased from 1 to 5% of total fatty acids and DG fatty acids from 0.5 to 4%, whereas TG fatty acids showed a corresponding decrease. The rate of liberation of FFA was in the order 18:2 〉 18:1 〉 18:0 〉 16:0 while MG and DG were enriched in 16:0. These results suggest specificity of lipolysis.

Notes: Soy curd-beef patties were made containing 0%, 5%, 10%, 20%, 75% and 100% (w/w) of curds which had been pressed at 300 psi, 600 psi and 1100 psi during manufacture. Taste panel tests showed that by increasing pressure on the soy curd or by the addition of flavoring to the curd before patty formation, increases in soy concentration became less detectable and the acceptability of the patties was drastically increased. Soy curd-beef patties made with 1100 psi curd and with color and flavor added were favorably accepted even at levels as high as 75% curd (w/w). The easy detectability of flavored soy in patties did not greatly change the high acceptability of the patties. The chemical composition, functional characteristics and physical properties of the soy-beef patties were also studied.

Notes: During ripening of dry sausage, disappearance of carbohydrates and production of lactate, volatile fatty acids, pyruvate and carbonyls was followed. When expressed as mmoles/100g of dry matter, carbohydrate disappearance (ca. 10 mmoles/100g dry matter) could be accounted for by production of lactate (ca. 17 mmoles) and acetate (ca. 2 mmoles) in two similar experiments. No differences were observed due to the presence of a starter culture in one experiment. In a third experiment, carbohydrate disappearance (ca. 16 mmoles) could only partly be accounted for by lactate (ca. 19 mmoles) and acetate (ca. 2 mmoles) production. Oxidative dissimilation of carbohydrates by micrococci during the early stages of ripening in the third experiment is offered as possible explanation.

Notes: Concentration changes for ammonia, total and individual free amino acids, total peptides, nucleotides, nucleosides and some individual amines were followed during ripening of dry sausage, with and without “starter culture.” A decrease was observed for peptides, nucleotides, glutamic acid, histidine, tyrosine and ornithine, an increase for all other compounds, being most intense for total free amino acids during the first days of ripening. The rate of free amino acid production exceeded the rate of ammonia production. The presence of a starter culture intensified free amino acid production and peptide disappearance. A tenfold increase in the concentrations of histamine, tyramine and putrescine was observed in the presence of a starter culture.

Notes: An apparatus for the extraction of leatherjackets (larvae of Tipula paludosa Meig.) from turf samples is described. Cores are retained in metal cutting cylinders and are stood turf surface downwards in dishes of cold water while heat is applied to the other end. The temperature gradient drives the leatherjackets down into the water. The system is very convenient to operate and is of acceptable efficiency.

Notes: In small-scale trials narcissus bulbs, cultivar Standard Value, heavily infested with bulb scale mite (Steneotarsonemus laticeps (Halb.) were treated with methyl bromide over a range of concentration x time products from 102 to 251 mg.hr/1. at temperatures between 19 and 24°C. All treatments killed both the mites and their eggs without damaging the bulbs. Fumigated bulbs flowered normally without stunting or distortion.

Notes: The vigour and yield of sugar beet grown on Heterodera schachtii-infested soils, with organic matter contents of 14 to 68 per cent, were increased by aldicarb granules applied in the seed furrow in field trials in eastern England in 1968 to 1970. Sugar yields were smallest on the most heavily infested sites; yield increases on plots treated with aldicarb were greatest at doses ranging from 11 to 31 oz active ingredient/ acre (770–2,170 g/ha), but increases were not enough to ensure a satisfactory crop. Post-crop numbers of cyst eelworm were not decreased by treatment. Other candidate nematicides - chlorfenvinphos, diazinon, fensulfothion, methomyl, ‘Neosar’, oxamyl, pirimiphos-methyl, ‘Prophos’, thionazin, RD 18502, C14421 and R17210-had no beneficial effect and several, especially at higher doses, were phytotoxic.

Notes: A virus has been isolated from celery crops in Lincolnshire, Cambridgeshire, and Norfolk, from eight different cultivars on 15 of 18 farms sampled, but has not been found in any cultivars on 10 farms in Lancashire. It has also been isolated from hemlock on three farms in Cambridgeshire. The incidence of infection has varied considerably with an average level of about 15 per cent but 90 per cent crop infections have been observed.The virus causes most prominent symptoms in cvs. Lathom Blanching and Fenlander, causing a slight stunting of the former and a more serious reduction in growth of the latter. It is aphid-transmitted in a non-persistent manner. The virus has flexuous rod-shaped particles approximately 780 nm in length, and is apparently restricted in its host range to the Umbelliferae. Its relationship to Western celery mosaic virus */*: */*: E/E: S/Ap is discussed.

Notes: The geographical distribution of trees of cricket bat willow (Salix alba var. caerulea) showing watermark symptoms of infection by Erwinia salicis (Day) Chester during 1955 to 1972 is recorded. In an attempt to control the disease by eradication, 23,172 trees were destroyed in this 18-year period, as were 911 mother trees (stools) producing propagating material. During an intensive survey in 1972, 301 trees and seven stools were found to be infected out of an estimated total crop of 400,000 trees. In that year, agglutination tests and culturing sap were used in addition to the examination of trees with symptoms other than watermarking in the wood. The field observations, together with some experimental inoculations, indicate that the main sources of the disease in the field each year probably are (1), the nearby stumps of felled diseased trees and (2) infected propagating material.

Notes: Runner production from strawberry plants was markedly affected by severity of verticillium wilt. Runners from 10 cultivars examined became infected by transmission of the pathogen through the stolon as well as from the soil. The ready isolation of the pathogen from symptomless parent plants and runners indicates one method by which this disease is spread to new plantations.

Notes: Since 1965, 146 early occurrences of blight on field crops were recorded in the East of Scotland before the end of July. Of these, 119 were investigated to determine the source of infection, and 78 were found to be associated with heaps of discarded potatoes on which Phytophthora infestans was actively sporulating.From samples of bright-affected foliage taken from such dumps a wide range of races was detected.In 1971 and 1972, attempts were made to control growth on discard heaps throughout East Lothian, a county in South-east Scotland relatively isolated with regard to spread of blight, to determine whether this would delay the onset of blight in this area. In 1971, blight was recorded first on 17 August whereas further north in the counties of Perth, Angus and Fife it was noted on 5 July. The same pattern obtained in the latter counties in 1972 but no field cases of blight were recorded in East Lothian during the whole season. However, neither season was a ‘blight year’.The lack of sources on potato dumps may have contributed to this delay, or even absence, of blight but other factors may well have had more influence. In the counties where blight occurred early i.e., in July, there was a highly significantly greater total acreage of potatoes, and also the proportion of this acreage devoted to the tuber-susceptible cultivar King Edward was very highly correlated with the incidence of early reports. The influence of such a cultivar was illustrated by the fact that 45 per cent of the outbreaks of blight recorded up to the end of July related to King Edward.

Notes: In 1972 a trial on susceptibility to carrot fly infestation was conducted on peat soil in East Anglia using 17 carrot cultivars sown on two dates one month apart. The only insecticide applied to the carrots was an aphicidal spray. The early-sown carrots were damaged by the first generation of larvae, but, by the second sampling date in October, there were no infestation differences between the two sowings. At harvest in December, significant differences in infestation levels occurred; these ranged from 82 per cent damaged roots for Amster-dammer Bak, 87 and 88 for two stocks of Royal Chantenay, to 97 per cent for Danvers 126. It is not yet clear whether the differences can be profitably exploited as an adjunct to other methods for controlling this pest.

Notes: In pot experiments, the fungicides captafol, chloraniformethan, dimethirimol, dinocap, dithianon, drazoxolon, folpet, miancozeb, mancozeb and zineb, terrazole, FUN 52.133, R 22395 and R 45173 decreased the per cent by number of strawberry roots infected by zoospores of Phytophthora fragariae. Only terrazole and R 22395 were more effective than Bayer 22555 which was used as a standard.

Notes: Tubers of Cyperus rotundus L. were planted in pots, and growth and development followed by washing out every 3 days. New tubers were first recorded 16 days after shoot emergence began, and tuber production proceeded at the rate of one every 4 days. By 51 days a single tuber had produced approximately nine new tubers, nine shoots and nearly 90 cm of rhizome. Treatment with 2,4-D or paraquat at 34 days severely checked shoot growth, but tuber production appeared to he only temporarily checked. Parent tuber dry weight fluctuated between 017 and 0–55 g and the parent tuber appears to act as a source of food in times of stress.Expériences sur le Cyperus rotundus L. I. Croissance et dé-veloppement: effets du 2,4-D et du paraquatDes tuberules de Cyperus rotunds L. ont été plantés dans des pots retires d'où ols lis ont été retirés tous les 3 jours pour en suivre la croissanec et le développement. On a enregistré l'apparition de nouveaux tubercules 16 jours après le début de la levée. La production de tubercules s'est poursuivie á raison d'un tous les 4 jours. Au bout de 51 jours, un tubercule avait produit approximativement 9 nouveaux tubercules, 9 pousses et prés de 90 cm de rhizome. Le traitement avec le 2,4-D et le paraquat au bout de 34 jours a provoqué un freinage important de la croissance de la partie aérienne mais la production des tubercules n'a été ralentie que temporairement. Les poids sees des tubercules initiaux ont varié entre 0.l7 g et 0.55 get ces tubercules paraissent jouer le röle d'une source de maliéres nutritives pendant les périodes difficiles.Versuche mit Cyperus rotundus L. I. Wachstum und Entwick-lung und Wirkung von 2,4-D und ParaquatKnollen von Cyperus rotundus L. wurden in Gefässe gepflanzt und das Wachstum und Entwicklung durch Auswaschen im Abstand von jeweils 3 Tagen verfolgt. Neue Knollen wurden zuerst 16 Tage nach dem Beginn der Sprossbildung beobachtet. Alle 4 Tage wurde eine weitere Knolle gebildet. Nach 51 Tagen hatte eine einzelne Knolle etwa 9 neue Knollen und fast 90 cm Khizom produziert. Eine Behandlung mit 2.4-D Oder Paraquat nach 34 Tagen hemmte das Sprosswachstum stark, aber die Knollenbildung schien nur vorübergehend gehemmt zu sein. Das Trockengewicht der Mutterknollen schwankte zwischen 0,17 und 0,55 g. Die Mutterknolle scheint in Zeiten in denen die Pflanze Belastungen ausgesetzt ist als Nährstoffquelle zu wirken.

Notes: Thirty-eight different agronomic and horticultural crop plants were tested for aryl acylamidase enzymes which could hydrolyse the amide bond of the herbicide, 3′,4′-dichloropropion-anilide (propanil). More than half of these plants, from ten different plant families, covering thirty genera, possessed enzymes capable of degrading propanil in this manner. Enzyme preparations from leaf lettuce (Lactuca sativa L.) appeared to be the richest source of aryl acylamidase activity. The total enzyme units present, as well as specific activities of enzymes from these plant tissue preparations, varied widely in the different plants.Hydrotyse du 3′,4′-dichtoropropionanitide par des aryt acylamytases vegetates.Trente-huit cultures différentes parmi lesquelles des plantes horticoles ont été essayées quant à la production d'aryl acylamylases, enzymes qui pourraient hydrolyser la liaison amidede l'herbicide 3′,4′-dichloropropionanilide (propanil). Plus de la moitié de ces plantes appartenant 4 10 families différentes et représentant 30 genres possèdent des enzymes capables de dégrader le propanil de cette maniére. Des préparations enzymatiques effectuées à partir de la feuille de laitue (Lactuca sativa L.) se sont révélées être les sources les plus abondantes d'activité aryl acylamylase. Le total des unités enzymatiques présentes, aussi bien que les activités spécifiques des enzymes extraites de ces préparations de tissus végétaux ont varié de façon importante selon les especes vegétales.Hydrolyse von 3′,4′-Dichlorpropionanilid durch pflanzliche ArytacytamidasenEs wurden 38 verschiedene landwirtschaftliche und gärtnerische Kulturpflanzen auf Arylacylamidase Enzyme untersucht, die die Amidbindung des Herbizids 3′,4′-Dichlor-propionanilid (Propanil) hydrolysieren konnten. Mehr als die Hälfte dieser Pflanzen, aus zehn verschiedenen Pflanzenfamilien, 30 Gattungen einschliessend, enthielten Enzyme, die Propanil auf diese Weise abzubauen vermochten. Enzymprapärationen von Kopfsalat (Lactuca sativa L.) schienen die ergiebigste Quelle für die Arylacylamidase-Aktivität zu sein. Die insgesamt vorhandenen Enzymeinheiten, als auch die spezifischen Aktivitäten der Enzyme der Gewebepräparationen, schwankten bei den verschiedenen Pflanzen ziemlich stark.

Notes: Experimental systems were produced from fragments of bracken rhizome and picloram-14C was applied to frond laminae, rhizome apices, frond buds and roots and translocation assessed 7 days after treatment. The isotope was readily taken up by all organs and freely translocated to associated fractions of the rhizome except in the case of laminae from which distribution was very poor. Accumulation of activity in the roots was considerable following treatment of the frond buds but was limited in the frond buds. Poor translocation of herbicide from treated frond laminae is considered a possible explanation of poor control in the field when bracken is sprayed in July.Lapplication du picioram e14C à la fougèreDes systèmes expérimentaux ont étéétablis en utilisant des fragments de rhizome de fougére et du piciorame 14C a été appliqué sur les limbes des frondes, les apex des rhizomes, les bourgeons des frondes et les racines. La migration fut évaluée sept jours aprés le traitement. L'isotope a été facilement absorbé par tous les organes et librement transporté aux fractions correspondantes du rhizome, sauf dans le cas des limbes è partir desquels la distribution a été très faible. L'accumulation de ractivité dans les racines a été considérable è la suite du traitement des bourgeons de frondes mais a été Iimitée dans les bourgeons de frondes. Une faible migration de I'herbicide depuis les limbes des frondes est considérée comme une explication possible du désherbage mediocre auchamp, lorsque la fougère est traitée en juillet.Die Anwendung von PicIoram-14C zu AdlerfarnAus Rhizomstücken von Adlerfarn wurden Versuchsp-flanzen gezogen und auf die Wedelspreiten, Rhizomapices, Wedelknospen und Wurzein- Picloram-14C appliziert. Die Transiokation des Herbizids wurde eine Woche nach der Behandlung gemessen. Das lsotop wurde von alien Pflan-zenorganen schnell aufgenommen und in die dem Rhizom benachbarten Pflanzenteile transloziert; bei Behandlung der Wedelspreiten war jedoch nur eine geringe Verteilung fest-zustellen. Nach Behandlung der Wedelknospen war in den Wurzein eine beträchtliche, aber in den Wedelknospen nur eine geringe Aktivitätsanreicherung feststellbar. Für den schwachen Bekämpfungserfolg des Adierfarns im Freiland bei Spritzungen im Juli, wird die geringe Transiokation des Herbizids aus den Wedelspreiten als mögliche Erklärung angesehen.

Notes: The effects of repeated defoliation of Oxalis latifolia H.B.K. and O. pes-caprae L. were studied under glasshouse conditions and the influence of different frequencies of defoliation by paraquat on O. latifolia was studied in the field. It is suggested that a useful degree of control can be achieved by regular and relentless defoliation of O. latifolia and O. pes-caprae before the 20- and 30-leaf stage, respectively. La lutte contre Oxalis latifolia H.B.K. et O. pes-caprae L. par défoliation.Les effets de défoliations répétées sur Oxalis latifolia H.B.K. et O. pes-caprae L. ont étéétudiés en serre et l'influence de différentes fréquences de defoliation par le paraquat sur O. latifolia a étéétudiée au champ. Il est suggéré qu'une limitation effcacc de O. latifolia et de O. pes-caprae peut être obtenue par une défoliation régulèdre et sans rémission avant les stades 20 et 30 feuilles respectivement. Bekämpfung von Oxalis latifolia H.B.K. und O. pes-caprae L. durch EntlaubungDie Wirkung wiederholter Entlaubung von Oxalis latifolia H.B.K. und O. pes-caprae L. wurden im Gewächshaus und die Wirkung verschieden häufiger Entlaubung mit Paraquat auf O. latifolia im Freiland untersucht. Die Ergebnisse deuten darauf hin, daβ eine brauchbare Bekämpfung von O. latifolia und O. pes-caprae durch eine regelmässige und unbarmherzige Entlaubung erreicht werden kann, bevor sie das 20- bzw. das 30-Blattstadium erreicht haben.

Notes: A spraying rig is described for the accurate application of herbicides to the floating leaves of water plants in experimental plots which may be inaccessible to land-based machinery. The rig, constructed of aluminium angle and supported by polystyrene floats, carries one operator who controls the sprayer. Apparatus for priming and washing out the sprayer is incorporated into the rig to prevent contamination of the water.The rig is towed along a guide rope from one bank to the other and sprays a swath up to 4 m wide at a speed of 0–5 m/sec and has been used to spray plots up lo 100 m in length. A total number of four persons is required to operate the rig.Un équipement de pulvérisation pour I'application expérimentale d'herbicides aux feuilles flottantes des plantes aquatiquesUn équipement de pulvarisation est décrit pour I'application precise d'herbicides aux feuilles flottantes des plantes aquatiques, dans des parcelles experimentales qui peuvent etre inaccessible A des appareils opérant depuis la terre. Cet équipement construct en corniére d'aluminium et supporté par des flotteurs en polystiréne transporte un opérateur qui fait fonctionner le pulvérisateur. Un appareil permettant le remplissage et le nettoyage du pulvérisateur est incorporé a l'équipement dans le but de prévenir toute contamination de I'eau.L'équipement est propulso par touage sur un cable de guidage tendu d'une rive a l'autre; il traite une bande jusqu'a 4 métres de large a une vitesse de 0,5 m/sec; il a été utilisé pour traiter des parcelles allant jusquà 100 m de long. Un nombre total de 4 personnes est nécessaire pour manoeuvrer Iéquipement.Ein Sprilzgeriit zur Durckfiihrung von Herbizidversucben hei WasserpfianzenEs wird ein Spritzgeriit fiir die genaue Ausbringung von Herbiziden auf die Schwimmblatter von Wasserpflanzen in Versuchsparzellen beschrieben die mit vom Land aus betriebenen Geräten nicht erreichbar sind. Das Gerät. eine Altiminiumkonstruktion mit Polyslyrol-Schwimmkörpern. Trägt eine Person, die die Spritze bedient. Um eine Verun-reinigungdes Wassers zu vermeiden. sind GerSte zum Fiillen und zum Reinigen der Sprilze in das Spritzgerfll eingebaut.Das Gerät ist an ein Führungsseil von Ufer zu Ufer befestigt und hat cine Spritzbreite bis zu 4 m, bei einer Geschwindigkeit von 0,5 m/sec. Es wurde zur Behandlung von Parzellen bis zu 100 m Lännge eingesetzt. Um das Gerilt zu bedienen, werden insgesamt 4 Personen benötigt.

Notes: In 1971 the net area of Cirsium arvense in Victoria was 1300 ha in permanent pasture, 120 ha in cropping land and 40 ha in non-agricultural land. In ten farms in the most heavily infested parish (approximately 100 km2). C. arvense was present in 35 % of the fields and occurred in some highly productive legume-based pastures. The most common control practice on these farms was pasture slashing. It was considered that the weed had been on the farms for 40–80 years.At a constant temperature of 20°C, but not at alternating temperatures, the germination percentage of seed was enhanced by pre-chilling. At constant temperatures the germination percentage was higher at 30°C than at lower temperatures. Alternating temperatures that included 30°C also increased the germination percentage, but it was depressed at 15°/40°C.The germination percentage of seed from forty sites was 52%-97% and some seed was formed where male and female plants were separated by distances of up to 390 m. However, no seed was found in about a third of the parishes examined.Distribution et production de semences de Cirsium arvense (L.) Scop, dans I'etat de Victoria en Australie.En 1971, la surface nette occupée par Cirsium arvense dans pétat de Victoria était de 1300 ha dans les prairies permanentes, de 120 ha dans les terres cultivées et de 40 ha dans les terres non agricoles. Dans 10 fermes situées dans la partie la plus infestée (approximativement 100 km2) C. arvense était present dans 35% des champs et apparaissait dans quelques pâtures hautement productives â base de 1égumineuses. La méthode de lutte la plus fréquente dans ces fermes était la pâture intensive. 11 était admis que la mauvaise herbe était présente dans les exploitations depuis 40 à 80 ans.A la temperature constante de 20°C, maisnon à des tempértures alternées, le pourcentage de germination des semen-ces fut augmenté par une réfrigération préalable. A température constante, le pourcentage de germination fut plus élevé k 30°C quà des temperatures plus basses. Les températures alternées, qui comprenaient celle de 30°C augmentérent aussi le pourcentage de germination, mats celui-ci diminua à 15°/40°C.Les pourcentages de germination de semences de 40 provenances différences se situa entre 52% et 97%; quelques semences furent formées dans des cas où les plantes mäles et les plantes femelles étaient séparées par des distances atteign-ant 390 m. Toutefois aucune semence ne fut trouvée dans un tiers environ des localities examinées.Verbreitung und Samenproduktion von Cirsium arvense (L.) Scop, in Victoria, AustralienDie mit Cirsium arvense verseuchte Flfiche in Victoria im Jahre 1971, gliedert sich auf in: 1 300 ha Daucrweide. 120 ha Ackerland und 40 ha nicht-landwirtschafllich genutzte Fläche. In 10 Betrieben des am stftrksten verseuchten Bezirks (ca. 100 km2), war C. arvense in 35% der Felder vorhanden und kam in einigen hochproduktiven Leguminosenweiden vor. Die gebräuchlichste Bekämpfungsmassnahme in diesen Betrieben war das Abmiihen mit Schlegelhilckslem. Es wird angenommen, dass dieses Unkraut seit 40 bis 80 Jahren in den Betrieben vorhanden ist.Bei einer konstanten Temperatur von 20°C, nicht aber bei Wecheseltemperaturen, wurde durch vorheriges Einfrieren die Keimungsrate erhöht. Bei konstanten Temperaturen war sie bei 30°C hSoUher als bei niedrigeren Temperaturen. Wechseltemperaturen die 30°C einschlossen, erhöhten auch die Keimungsrate; bei 15°C/40°C war sie aher geringer.Die Keimung der Samen von 40 Siandorten betrug 52% bis 97%. Wenn weibliche und mflnnliche Pfianzen his zu 390 m von einander entfernt waren. wurden noch einige Samen gebildet. In etwa einem Drittel der untersuchten Bezirke wurden jedoch keine Samen gefunden.

Notes: The rhizome tips of Poa pratensis L. are inherently negatively geotropic but grow horizontally under the dominance of the apices of their parent tillers. This dominance is rapidly lost when the rhizome tips are exposed to light. The dominance, which is also associated with the lack of cataphyll development, was increased by defoliation and when light was excluded from the parent tiller, was reduced by addition of nitrogen, but was unaffected by orientation of the rhizome apex. The axillary buds on the rhizome may abort, remain dormant, grow into rhizomes or produce aerial shoots. They are primarily under the apical dominance of the rhizome apex, but their dormancy was broken by light. In the intact plant, buds distal to the rhizome apex lost dormancy earliest but removal of the rhizome apex caused buds proximal to the cut stump to grow most rapidly. These results are discussed and comparisons are made with other rhizomatous species.Quelques aspects de la physiologie des rhizomes de Poa pratensis L.Les extrémités des rhizomes de Poa pratensis L. sont, par nature, négativement géotropiques mais poussent horizontalement sous la dominance des apex de leurs talles apparentées. Cette dominance disparait rapidement lorsque les extré-mités des rhizomes sont exposés à la lumiére. La dominance, qui est aussi associée avec le manque de developpement de la cataphylle a été augmentée par la defoliation et lorsque les talles apparentées ont été soustraites à Faction de la lumiére; elle a été réduite par apport d'azote mais n'a pas été influence par l'orientation de l'apex du rhizome. Les bourgeons axillaires sur le rhizome peuvent avorter, rester dormants, se développer en rhizomes ou produire des tiges aériennes. Ils sont tout d'abord sous la dominance apicale de l'apex du rhizome, mais leur dormance a été rompue par la lumiére. Dans la plante intacte, les bourgeons en position distale par rapport k l'apex du rhizome rompent leur dormance plus tot mais l'enlévement de l'apex du rhizome provoque, chez les bourgeons en position proximale par rapport à l'extrémité coupée, une croissance beaucoup plus rapide. Ces résultats sont discutés et des comparaisons sont faites avec d'autres espéces rhizomateuses.Einige Gesichtspunkte zur Physiologie der Rhizome von Poa pratensis L.Bei Poa pratensis L. verhalten sich die Rhizomspitzen von Natur aus negativ geotrop, aber durch Dominanz, die von den Sproβspitzen der Mutterpflanzen ausgeht, wachsen sie horizontal. Diese Dominanz wird rasch aufgehoben, wenn die Rhizomspitzen dem Licht ausgesetzt werden. Die Dominanz, die ferner mit einer fehlenden Entwicklung von Niederblättern an den Rhizomen einhergeht, wurde durch Entfernen der Blätter verstärkt, ebenso, wenn den Mutters-prossen das Licht entzogen wurde. Die Dominanz wurde durch Zugabe von Stickstoff gemindert; die Ausrichtung der Rhizomspitzen spielte jedoch keine Rolle. Die Axillarknospen an den Rhizomen konnen verkümmern, dormant bleiben, als Rhizome austreiben oder oberirdische Sprosse bilden. Sie stehen in erster Linie unter apikaler Dominanz der Rhizomspitzen, aber ihre Dormanz wird durch Licht gebrochen. Bei intakten Pflanzen verloren die im Hinblick auf die Rhizomspitze distalen Knospen ihre Dormanz am fruhesten, aber ein Entfernen der Rhizomspitze veranlasste die zum Schnittende hin proximal gelegenen Knospen am schnellsten zum Austreiben. Diese Ergebnisse werden diskutiert und Vergleiche mit anderen rhizombildenden Arten angestellt.

Notes: The establishment of crops direct-drilled after various times into swards treated with paraquat (1,1′-dimethyl-4,4′-bipyridylium- 2/A) was examined. Best results with Brassica napus and B. oleracea were obtained with 1–1 kg/ha applied 7 days before drilling and 2–3 kg/ha applied 14 days before. Although delaying drilling from 7 to 14 days after application reduced the phytotoxicity, the higher dose was needed when drilling was delayed, to reduce competition from the sward regrowth. In the glasshouse, mulches of paraquat-treated herbage affected seedling growth and development of Brassica napus, Hordeum vulgare and Lolium perenne; B. napus was the most susceptible.Quelques effets du paraquat sur des cultures implantées aprés destruction d'herbagesL'implantation de cultures en semis direct, apres divers intervalles de temps, dans des herbages trait6s au paraquat (l,r-diméthyl-4-4′-bipyridylium-2/4) a été examinée. Avec Brassica napus et B. oleracea, les meilleurs résultats ont été obtenus par des applications de 1,1 kg/ha et de 2,3 kg/ha, respectivement 7 jours avant et 14 jours avant le semis. Bien que le fait de porter de 7 à 14 jours le délai entre le traitement été le semis ait réduit la phytotoxicité, la dose la plus forte a été nécessaire lorsque le semis a été retardé, pour réduire la competition due à la repousse de la prairie. En serre, des paillis d'herbages traités au paraquat ont affecté la croissance et le développement de Brassica napus, Hordeum vulgare et Lolium perenne; B. napus s'est montré le plus sensible.Einige Effekte von Paraquat auf die Entwicklung von Kulturpflanzen in abgetöteten PflanzendeckenEs wurde die Entwicklung von Kulturen untersucht, die in unterschiedlichen Zeitabständen direkt in mit Paraquat (l,l'-Dimethyl-4,4′-bipyridylium-2/4) behandelte Pflanzendecken gesät wurden. Die besten Ergebnisse mit Brassica napus und B. oleracea wurden erzielt, wenn 1.1 kg/ha 7 Tage und 2 3 kg/ha 14 Tage vor der Saat gespritzt wurden.

Notes: The reproduction of blackberry (Rubus fruticosu L. agg.) is described with particular reference to R. procerus P.J. Muell. Reproduction is by seed, rooting at cane apices, suckering of lateral roots, and from pieces of roots and canes.In Victoria, Australia, R. procerus occurs mainly in non-agricultural land and neglected pastures and is rare in well-managed pastures and crops. This is attributed to the poor establishment of seedlings and the ease with which rooting at cane apices may be prevented by grazing, cultivation or spraying with 2,4,5-T.To eradicate established thickets it is necessary to kill the roots by frequent cultivation or to apply herbicides lo prevent the formation of root suckers. Ecologie des ronces (Rubus fruticosus L. agg.) et méthodes dc lutte II ReproductionLa reproduction des ronces (Rubus fruticosus L. agg.) est décrite avec une reference particulière au R. procerus P. J. Muell. La reproduction s'opère par les semences, l'enracine-ment d'apex de tiges, la formation de drageons À partir de racines laterales et de fragments de racines et de tiges.Dans l'Etat de Victoria, en Australie, R. procerus apparaît surtout dans les terres non cultivées et les pâtures mal entretenues; cette espèce est rare dans les pâtures bien entretenues et dans les cultures. Ce fait est attribuéà la difficile implantation des plantules et h la facility avec laquelle la formation de drageons à partir des apex des tiges peut être prévenue par le pâturage, les façons culturales, ou le traitement au 2,4,5-T.Pour éliminer les fourrés élablis, il est nécessaire de tuer les racines par des façons culturales fréquentes et d'appliquer des herbicides pour prévenir la formation de drageons à partir des racines. Ökologie und Bekämpfung der Brombeere (Rubus fruticosus L. agg.) II. VermehrungEs wird die Vermehrung der Brombeere (Rubusfrur ic osus L. agg.) unter besonderer Berucksichtigung von Rubus procerus P.J. Muell. beschrieben. Die Vermehrung erfolgt durch Samen, Bewurzelungvon Sprossspitzen (Ruten), Bildung von Wurzelsprossen aus Seitenwurzein und durch Wurzel-und Sprossteile.In Victoria, Australien. kommt R. procerus hauptsächtich auf nicht landwirtschaftlich genutzten Flächen und auf vernachliissigten Weiden vor, selten dagegen auf gut gep-flegten Weiden und auf Ackerland. Dies ist auf das geringe Ausbreitungsvermogen der Samlinge und auf die einfache Verhinderung der Bewurzelung der Sprosspitzen durch Beweiden, Bewirtschaftung oder Spritzung mit 2,4,5-T zurückzuführen.Um ein altes Dickicht auszurotten ist cs notwendig, die Wurzeln durch mehrmalige Bodenbearbeitung abzutöten oder durch Herbizidspritzung die Ausbildung von Wurzelsprossen zu verhindem.

Notes: A machine is described for experimental application of herbicides in volumes of spray liquid in the range 5–20 I/ha and at a uniform drop size. Uniformity of distribution is comparable to that from a conventional small-plot sprayer working under optimal conditions. The machine was used to apply 2,4-D ester, barban and tri-allate. Subsequent biological assessments revealed no major loss of effectiveness in weed control when compared with applications in 165 or 200 I/ha sprayed through hydraulic fan nozzles as in contemporary field practice.Essais préliminaires au champ avec l'ester du 2,4-D, le barbane et le triallate appliqués en pulvérisation avec un volume de 5 à 20 l/haUn appareil est décrit pour l'application expérimental d'herbicides en pulvérisation avec un volume de liquide alla de 5 à 20 I/ha et une taille uniforme de gouttes. L'uniformité de la distribution est comparable à celle d'un pulvérisateur pour petites parcelles travaillant dans des conditions optimales. L'appareil a été utilisé pour appliquer du 2.4-D ester, du barbane et du triallate. Des essais biologiques effectués & la suite des traitements ont montré qu'il n'y avait pas de perte importante d'efficacité herbicide par comparaison avec des traitements appliqués avec 165 ou 200 1/ha en utilisant les buses S fente en usage dans la pratique actuelle des traitements au champ.Vorläufige Feldversuche mit 2,4-D Ester, Barban und Triallat mit Brühemengen von 5–20 l/haEs wird ein GerSt beschrieben mit dem versuchsmässig Herbizide mit Brühemengen zwischen 5 und 20 1/ha bei gleichbleibender Tropfengrösse ausgebracht werden können. Die Gleichmässigkeit der Verteilung lässt sich mit der eines unter optimalen Bedingungen arbeitenden Parzellenspritz-geräts vergleichen. Mit diesem Gerät wurden 2,4-D Ester, Barban und Triallat ausgebracht. Die darauffotgende bio-logische Früfung zeigte keinen wesentlichen Verlust in der Wirksamkeit der Unkrautbekämpfung, verglichen mit den gegenwärtig üblichen Verfahren mit 163 oder 200 l/ha und Flachstrahldüsen.

Notes: The uptake and translocation of 14C-labelled 4-chloro-5-(dimethytamino)-2-(α,α,α,-trifluoro-m-lolyl)-3(2H)-pyridazinone (SAN-6706) and 4-chloro-5-(melhylamino)-2-(α,α,α,-trifluoro-m-tolyt)-3(2H)-pyridazinone (SAN-9789) were studied in cranberry plants (Vaccinium macrocarpon Ait. cv. EarlyBlack). The plants were treated in water solution and sampled at 1,3,8 and 15 days. Other plants were treated for these times, washed free from extraneous herbicide, grown for 3 weeks longer in nutrient with no herbicide and then sampled to determine the fate of the herbicide. Both compounds were readily translocated and the amount of label present in the shoot increased with time. In plants grown for 3 more weeks after treatment there was translocation of the label from the root to the shoot. No radioactive label was detected in the cranberry fruit.Absorption et migration du 14C-SAN-6706 et du 14C-SAN-9789 chezVaccinium macrocarpon cv. Early BlackL'absorption et la migration de la 4-chloro-5-(dimeAthyiamino)-2-(α,α,α-trifluoro-m-tolyl)-3(2H)-pyridazinone (SAN-6706) et de la 4-chloro-5-(méthylamino)-2-(α,α,α-trifluoro-m-tolyl)-3(2H) pyridazinone (SAN 9789), marquées au 14C, ont été eAtudiées chez la canneberge (Vaccinium macrocarponAit, cv. Early Black). Les plantes ont été traitées en solution aqueuse et échantillonnfées aprés 1, 3, 8 et 15 jours. D'autres plantes ont éteA traitées pour ces mêmes durées, Iavées pour éliminer les traces externes d'herbicide, et cultivées pendant 3 semaines de plus en milieu nutritif sans herbicide, et enfin échantillonnées pour determiner le devenir de L'herbicide. Les deux composes migrerent rapldement et la quantité de produit marqué présente dans la partie adrienne augmenta avec le temps. Dans les plantes cultivées 3 semaines supplémentaires aprés le traitement, il y eut migration du produit marque des racines vers les tiges. Aucun élément radioactif n'a été décelé dans les fruits de canneberge. Die Aufnahme und Translokatlon von 14C-SAN-6706 und14CSAN-9789 bei Vaccinium macrocarpon Sorte Early BlackEs wurde die Aufnahme und Translokation von 14C-markiertem 4-Chlor-5-(dlmcthylamino)-2-(α,α,α;-trifluor-m-tolyl)-3(2H)-pyridazinon (SAN-6706) und 4-Chlor-5-(methylamino)-2-(α,α,α-trifluor-m-tolyl)-3(2H)-pyridazinon (SAN-9789) bei Preiselbeerpflanzen (Vaccinium macrocarpon Ait. Sorte Early Black) untersucht. Die Pflanzen wurden in Wasserkultur behandelt und nach 1, 3, 8 und 15 Tagen Proben genommen. Bei anderen Pflanzen, die auch über diese Perioden behandelt worden waren, wurde anschliessend das äuβerlich anhaftende Herbizid abgewaschen, für 3 weitere Wochen in NaUhrlösung ohnc Herbizid gehalten und dann Proben gezogen, um die Verteilung des Herbizids zu bestimmen. Beide Verbindungen wurden rasch transloziert und der Gehait an markierter Substanz im Spross nahm mit der Zeit zu, in den Pflanzen die für 3 weitere Wochen nach der Behandlung gewachsen waren, wurde Translokation voti der Wurzel in den Spross festgestellt. In der Preiselbeerfrucht konnte keine Radioaktivität festgestellt werden.

Notes: Le méthabenzthiazuron (MBT) migre rapidement des racines vcrs Ies feuilles, où il est plus ou moins activement métabolisé selon l'espéce végétale considérée. Les transformations métaboliques du MBT permettent d'isoler en particulier un catabolite (hydroxymethyle du MBT) relativement stable. Ce dernier est à l'origine d'une voie métabolique qui démé-thyle peu à la chaine urée. D'autre part nous avons identié des produits de condensation avec le glucose. Quelques réactions métaboliques réversibles libêrent à nouveau du MBT à partir de certains de ses méatabolites.Verteilung und Metabolismns von Metiiabenzihiazuron in empfindlichen odcr resistenten PffanzenartenMethahenzthiazuTon (MST wird scbnell von den zu den Blättem geleitet, wo es, abhängig von der jeweiligen Art, mehr oder weniger stark melabolisiert wird. Die Umwand-lung von MBT ermöglicht insbesondere die Isolierung eines reiativ stabilen Abbauprodukts (Hydroxylmethyl-MBT). Letzeres steht am Anfang eines Abbauwegs bei dem stufen-weise die Hamstoifkette demethyliert wird. Ausserdem wurden einige Kondensationsprodukte mit Glucose identifi-ziert. Verscliiedene reversible Stoffwechselreaktionen können auch MBT aus bestimmtcn Metaboliten freisetzen.Distribution and metabolism of methabenzthiazuron in susceptible or resistant plant speciesMethabenzthiazuron (MBT) passes rapidly from the roots towards the leaves where it is more or less actively metabolized depending upon the species considered. In particular, the metabolic transformations of MBT allow the isolation of a relatively stable catabolite (hydroxymethyl-MBT). The latter is the origin of a metabolic pathway which gradually deme-thylates the urea chain. Additionally, some products of condensation with glucose have been identified. Several reversible metabolic reactions can also release MBT from certain of its metabolites.

Notes: Metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4/f)-one] has shown promise for weed control in Glycine max (L.) Merr. (soybean), but at rates effective for preemergence weed control soybean tolerance has been narrow and field observations indicated that varieties of soybeans differed in their tolerance.Treatments of 0.0,0.56,1,12 and 1,68 kg/ha an location in the Coastal Plain, Piedmont, and Limestone Valley-area of Georgia indicated that the soybean variety ‘Coker 102’ was Meterially more susceptible to metribuzin injury than were ‘Hardee’, ‘Bragg’, ‘Bienville’, ‘Hampton 266 A’, or ‘Coker 318’. The injury caused smaller soybean stands, heights, and yields. These results confirmed previous observations from field trials using this herbicide. Différences de sensibilités variétales chez le soja vis-à-vis de la métribuzine La métribuzine [4-amino-6-tert-butyl-3-(méthylthio)-as-triazine-5(4H)-one] a donné des résultats prometteurs pour le Désherbage du soja Glycine max (L.) Merr. Aux doses efficacies pour le désherbage en prélevée, la résistance du soja a étéétroite et les observations faites au champ ont mis en évidence des difféarences de sensibilité entre les variétés de soja.Des traitements à raison de 0,0, 0,56, 1,12 et 1,68 kg/ha à des emplacements situfés dans les régions suivantes: Coastal Plain, Piedmont et Limestone Valley, dans l'éatat de Georgie, ont montré que la variété de soja ‘Coker 102’était notablement plus sensible à la métribuzine que les varietés ‘Hardee’, ‘Bragg’, ‘Bienville’, ‘Hampton 266 A’ ou ‘Cocker 318′. Les dégâts se traduisirent par une réduction de Ia vigueur, de lataille et du rendement. Ces résultats confirment les observations antérieures dans des essais au cham pavec cet herbicide.Unterschiede in der Toleranz von Metribuzin gegenüber Sojabohnensorten[4-Amino-6-tert.-butyl-3-(methylthio)-as-triazin-5(4H)-one] ist ein aussichtsreiches Herbizid für die Unkrautbekämpfung in Glycine max. (L.) Merr. (Sojabohne). Bei wirksamen Aufwandraengen im Vorauflaufverfahren war die Sojabohnentoleranz wenig ausgeprägt und Feldbeobachtungen zeigten, dass Sojabohnensorten unterschiedlich tolerant sind.Behandlungen mit 0,0, 0,56, 1,12 und 1,68 kg/ha an Standorten in der Coastal Plain, Piedmont und der Limestone Valley-Gegend in Georgia zeigten, dass die Sojabohnensorte ‘Coker 102’ erheblich empfindlicher gegenuber Metribuzinschaden war als ‘Hardee’, ‘Bragg’, ‘Bleinville’, ‘Hampton 266 A’ oder ‘Coker 318′. Der Schaden äusserte sich in geringeren Bestandesdichten, Pflanzenhöhen und niedrigeren Erträgen. Diese Ergebnisse bestätigen die schon früher mit diesem Herbizid gemachten Beobachtungen in Freilandversuchen.

Notes: Seven field experiments in spring wheat and barley with natural infestations ot A. fatua were set up to investigate the effects on grain yield of removing the weeds by hand at intervals during early growth stages. Only three sites showed any significant yield reductions and these all had populations of wild oats of 150 stems or more per m2 at harvest. No significant yield reductions occurred at lesser densities (20–100/m2). At the three higher-density sites, competitive effects did not start until the crop had four leaves, about 4–5 weeks after it had emerged. A further experiment in a glasshouse designed to test if competition occurred prior to the emergence of crop and weed indicated no effect at all during this period. Lépoque du déclenchement de la compétition entre la folle avoine (Avena fatua L.) et les céréales de printempsSept essais ensemencés en blé de printemps et en orge on t été implantés dans des champs présentant des infestations naturelles d'Avena fatua, en vue dévaluer les effets, sur le rendement en grain, de l'extirpation des mauvaises herbes à la main, à des intervalles réguliers durant les premiers stades de la croissance.Trois essais seulement on t accusé des réductions significa-tives des rendements et ceux-ci avaient tous des populations de folle avoine de 150 pieds ou plus au m2 à la récolte. II n'y a pas eu de réductions significatives de rendement pour des densités inférieures (de 20 à 100/m2). Dans les trois essais à densitéélevée, les effets compétitifs ne commencérent pas avant que la plante cultivée ait atteint le stade 4 feuilles, 4 à 5 semaines environ aprés sa Ievée. Une expérience ulté-rieure en serre réalisée pour rechercher si la compétition se produit avant la levée de la plante cultivée et de la mauvaise herbe n'a montré aucun effet durant cette pédode. Der Zeitpunkt des Beginns einer Konkurrenz zwischen Flughafer (Avena fatua L.) und SommergetreideEs wurden sieben Feldversuche mit Sommerweizen und-gerste mit einer natürlichen Verseuchung von A. fatua angelegt, um den Einfluss einer Beseitigung der Unkräuter von Hand zu verschiedenen Entwicklungsstadien auf den Kornertrag zu messen. Nur bei drei Versuchen waren ge-sicherte Ertragsrückgänge festzustellen; die Flughaferdichte betrug in diesen Fällen zum Erntezeitpunkt 150 oder mehr Halme je m2. Bei geringeren Dichten (20–100/m2) waren keine gesichterten Ertragsminderungen feststellbar. In den drei Versuchen mit den höheren Dichten setzte die Konkurrenz nicht ein bevor das Getreide im 4-Blattstadium war; das waren etwa 4–5 Wochen nach dem Aufiaufen. Es wurde ein weiterer Versuch im Gewächshaus angelegt, um festzustellen, ob die Konkurrenz vor dem Auflaufen des Ge-treides und des Unkrauts eintrat. Während dieser Periode war kein Einfluss festzustellen.

Notes: Ten herbicides, bromacil, chlorthal-dimethyl, diphenamid, diuron, fluometuron, neburon, prometryne, pyrazon, simazine and trifluralin at two doses were repeatedly sprayed, in autumn and in spring, for 4 consecutive years on non-cultivated, sprinkler-irrigated field plots. Herbicidal effect was assessed at 1–2 month intervals on the natural weed population and after each observation a paraquat + diquat spray destroyed emerged weeds. The response of various weed species to herbicides varied markedly but a herbicide-induced shift in the composition of weed population did not occur, presumably because of the paraquat treatment.The overall phytotoxicity to weeds present was, in decreasing order: diuron, bromacil, simazine, trifluralin, prometryne, neburon, fluometuron, pyrazon, diphenamid, chlorthal-dimethyl. Persistence of herbicides was in decreasing order: diuron = bromacil, simazine, neburon (at higher rate), fluometuron, trifluralin, prometryne. Control produced by pyrazon improved with the number of applications, but that of diphenamid and chlorthal-dimethyl remained weak and short. After repeated applications, the activity of these herbicides increased or remained at similar level, but in no case decreased.Soil samples were taken 5 months after each application and bioassayed. Phytotoxic residues were detected beneath the disturbed top-soil from bromacil, diuron, fluometuron and simazine after the first application, and from neburon after the second application; residues from trifluralin were found in the top soil only after the fifth application. After the seventh spraying, residues of bromacil were found in the 45–60-cm soil layer.Ammonia content in soil samples taken from treated plots after the fourth, sixth and seventh application was generally similar to the untreated control. In these samples, nitrate content appeared to be correlated negatively with remaining weed number; the control thus contained less nitrate than efficient herbicidal treatments. Soil samples taken after the seventh application of bromacil, diuron, fluometuron, neburon and simazine, which contained appreciable residual concentrations, did not show significant differences from control, in an in vitro nitrification test.

Notes: The survey was carried out over an area representing about 47% of the cereal acreage of the United Kingdom.Estimates of the acreage of fields containing wild oat (Avena fatua L. and A. ludoviciana Dur) ranged from 15% (Northern Ireland) to 74% (England, South West Region). The degree of infestation over the total acreage was 58%‘light’, 34%‘medium’, and 8%‘heavy’.Blackgrass (Alopecurus myosurodies Huds.) was found only in the central and southern regions, estimates of the infested cereal field acreage ranging from 2% (Wales) to 23% (South East England).Nine per cent of the fields were rogued for wild oat. On average, only 10% of the infested acreage received herbicide treatment for wild oat and blackgrass though, in some regions, up to 23 % was treated. The timing of treatment and the herbicide used were recorded. Information on the extent and type of herbicide used for broad-leaved weeds was also recorded. Data on sowing dates of the crops, the previous cropping, previous infestations, the soil type and the state of field drainage were obtained and were correlated with the incidence of wild oat and blackgrass where relevant.

Notes: Seed dormancy and germination in sand burr (Cenchrus longispinus (Hack,) Fern,) were investigated in laboratory and field studies. The burrs contain two types of seeds which differed in their innate dormancy. Primary seeds formed in the upper spikelet usually germinated within a year. Secondary seeds from lower spikelets germinated slowly and remained dormant for longer periods. Dormancy was enforced at low and high temperatures, and secondary seeds apparently developed an induced dormancy when continuously exposed to high temperatures. More than 94 % of the seedlings established during spring. Light suppressed germination, and secondary seeds also developed an induced dormancy when stored in the light. Burrs sown on the soil surface had an extended period of germination lasting for more than 3 years. However, over 96 % of the seeds sown below the surface of bare soil germinated within 2 years. Deep burial did not enforce dormancy, but germination was suppressed by the presence of live vegetation. It is concluded that treatments which disturb the soil and bury the burrs will stimulate the germination of dormant seeds.

Notes: Experiments were conducted to establish if the formation of 2.4-dichlorophenol (DCP) from 2.4-dichlorophenoxyacetic acid (2,4-D) in plants proceeds via 3-(2,4-dichtorophenoxy) propionic acid (2,4-DP) as an intermediate.Soybean (Glycine max (L.) Merr.), kidney bean (Phaseolus vtitgaris L.), pea (Pisum. sativum L.), smooth bromegrass (Bromus inermis Leyss.), wild oat (Avena fatua L.), yellow foxtail (Setaria glauca(L.) Beauv.), barley (Hordeum vulgare L.), timothy (Phleum pratense L.). and orchardgrass (Dactylis glomerata L.) were treated with equal weights of 2,4-D and 2,4-DP. After 3 days, all plants contained DCP; however, amounts were larger in plants treated with 2.4-DP than in those treated with 2,4-D. The 2.4-DP was absorbed from the leaf surface more efficiently than 2,4-D.No evidence was found for formation of 2,4-DP from 2,4-D in any of the plant species studied.L'absence de l'acide3-(2,4 dichlorophénoxy) propionique dans les plantes traitées avec I'acide 2,4-dichlorophénoxyacétiqueDes experiences ont été effectuées pour rechercher si la formation de 2,4-dichlorophénoI (DCP) dans les plantes, à partir de l'acide 2.4-dichlorophénoxy acétique (2,4-D) se produit par l'intermêdiaire de l'acide 3-(2,4-dichlorophenoxy) propionique.Le soja (Glycine max(L.) Merr.). le haricot (Phaseolus vuigaris L.), Ic pois (Pisum sativum L.), le brome (Bromus inermis Leyss.), la folle avoine (Avena fatua L.), la sétaire (Setaria glauca(L.) Beauv.). I'orge (Hordeum vulgare L.), la fléole (Phleum pratense L.) et le dactyle (Dactylis ghmerata L.) ont été traités par des poids égaux de 2.4-D et de 2,4-DP. Trois jours aprés, les plantes contenaient du DCP; toutefois, les quantités trouviés furent plus importantes dans les plantes traitées avec le 2,4-DP que dans celles traitées avec le 2,4-D. Le 2,4-DP a été absorbéà partir de la surface foliaire plus efficacement que le 2,4-D.La formation du 2,4-DP à partir du 2,4-D n'a pu être prouvée dans aucune des plantes étudiécs.Die Abwesenheit von 3-(2,4′Dichlorphenaxy)-propionsäure irt mil 2,4-Dichlorphenoxytesäure behandelten PflanzenEs wurden Versuche durchgeführt um herauszufinden. ob die Bildung von 2,4-Dichlorphenol (DCP) aus 2.4-Dichlor-phenoxyessigsäure (2,4-D) in Pflanzen über 3-(2,4-Dichlor-phenoxy)-propionsaure (2,4-DP) als Zwischcnprodukt ver-läufl.Sojabohnen (Glycine max(L.) Merr.), Gartenbohnen (Phaseolus vutgaris L.), Erbsen (Pisum sativum L.), Wehrlose Trcspe (Bromus inermis Leyss.), Flughafer (Avena fama L.), Gelbe Borsienhirse (Setaria glauca(L.) Beauv.), Gerste (Hordetim vidgarc L.), Wiesenlieschgras (Phleum pratense L.) und Knaulgras (Dactylis ghmerata L.) wurden mit gleichen Mengen an 2,4-D und 2,4-DP behandelt. Nach drei Tagen enthielten alle PHanzen DCP; aber die Menge an DCP war in den mit 2,4-DP behandelten Pflanzen grosser als in den mit 2,4-D behandelten. 2,4-DP wurde von der Blatt-oberflache besser absorbiert als 2.4-D.In keiner der untersuchten Pflanzenarten konnte ein Hinweis für die Bildung von 2,4-DP aus 2,4-D gefunden werden.

Notes: The effect of diquat and morfamquat on the fine structure of leaf ceils has been investigated in corn marigold (Chrysanthemum Segetum L.), flax (Linum usitatissitmum L. cv. Redwing), and barley (Hordeum vulgare L. cv unknown). Barley seedlings were exceedingly resistant lo morfamquat and appeared virtually unaffected by the treatments used. Chrysanthemum segetum and flax seedlings were sensitive and in both species treatment with herbicide at concentrations of 10−4M, or greater, caused swelling of the chloroplasts within 3–4 h. The change of shape of the chloroplasts continued until they were more or less spherical. Eventually the cell tonoplast and plasmalemma broke down and this was immediately followed by rupture of the chloroplast envelope. Other cell organelles disintegrated and. finally, all that remained in the cells were the membranous components of the chloroplasts and granular material from the nucleus. With flax the early effects also look place when the material was treated with these herbicides in the dark.Quelques effets du diquat et du morphamquat sur la structure fine des cellules foliairesL'effet du diquat et du morphamquat sur la structure fine des cellules foilaires a étéétudié chez le chrysanthéme des moissons (Chrysanthemum segetum L.), le lin (Linum usitatissimum L. ev Redwing) et l'orge (Hordeum vulgare L. cv inconnu). Les ptantules d'orge se sont montrées extrémement résistantes au morphamquat et n'ont pratiquement pas été affectés par les traitements effectués. Le Chrysanthemum segetum et les semis de lin se sont révé1és sensibles et, pour ces deux espéces, le traitement avec I'herbicide a des concentrations de 10−4 M OU plus, a provoqué le gonflement des chloro-plastes dans un intervalle de 3 ä 4 heures. Le changement de forme des chloroplastes se poursuivit jusquá ce qu'ils devins-sent plus ou moins sphériques. Par la suite, les membranes vacuolaires et les plasmalemmes se rompirent et ceci fut immédiatement suivi par la rupture de I'enveloppe du chloro-plaste. Les autres organelles cellulaires se desinttgrerent et finalement ne subsisterent dans les cellules que Ies constituants de la membrane des chloroplastes et le matériel granuleux provenant du noyau. Chez le lin, les premiers effets apparurent également lorsque le matériel fut traitéà I'obscurité avec ces herbicides.Einige Effekte con Deiquat und Morfamquat auf die Struktur von BlattzellenEs wurde die Wirkung von Deiquat und Morfamquat auf die Struktur der Blattzellen der Saat-Wucherblume (Chrysanthemum segetum L.), Flachs (Lintim tisitatissinium L.) und der Gerste (Hordeum itilgare L.,) untersucht. Die Gersten-sitmlinge waren gegenüber Morpham quat ausserordentlich resistent und wurden durch die Behandlungen unscheinend nicht beeinträchtigl. Die Sämlinge der Saat-Wucherblume und Flachs waren empfmdlich. Bei beiden Arten trat bei 10−4 molaren und höheren Herbizidkonzcntrationen innerhalb von 3–4 Stunden eine Schwellung der Chloroplasten auf. Die Formveränderung der Chloroplasten schritt fort, bis sie mehr oder weniger kugelformig waren. Schliesslich erfolgte der Zusammenbruch vonTonoplast und Plasmalemma, unmittelbar gefolgt vom Bruch der Chloroplastenmembran. Die anderen Zellorgaitellen lösten sich in ihre Bestandteile auf und was letztlich in den Zellen übrig blieb, waren Bestandteile der Chloroplastenmembran und granulöses Material vom Zellkern. Bei Flachs wurden die AnfangsePffekte auch dann beobachtet, wenn er mit diesen Herbiziden im Dunkeln behandelt wurde.

Notes: The relative susceptibility of Digitaria sanguinalis (L.) Scop, (large crabgrass), Echinochloa crus-galli (L.) Beauv. (barn-yardgrass), Eriochloa villosa (Thumb.) Kunth. (hairy cup-grass), Setaria faberi Herrm. (giant foxtail), Setaria lutescens (Weigel) Hubb. (yellow foxtail), Setaria viridis (L.) Beauv. (green foxtail) and Setaria viridis var. robusta-purpurea Schreiber (robust-purple foxtail) to alachlor, atrazine, butylate and cyanazine was studied under glasshouse conditions. Hairy cupgrass was the least susceptible to the herbicides tested, of which alachlor appeared to be the most effective. Large crabgrass was controlled by alachlor, butylate and cyanazine at all of the rates tested, but by atrazine only at rates above 0–56 kg/ha. All four herbicides provided acceptable control for barnyardgrass, giant foxtail, green foxtail, robust-purple foxtail, and yellow foxtail. The susceptibility of the grasses to cyanazine and alachlor was correlated with seed size. Alachlor was more effective in controlling green foxtail and hairy cupgrass when applied to the soil surface before emergence than when incorporated into the soil prior to sowing.Sensibility de sept graminées annuelles à divers herbicidesLa sensibilité relative des espéces suivantes: Eriochloa villosa (Thumb,) Kunth. Echinochloa crus-galli (L.) Beauv. (panic). Digitaria sanguinalis (L.) Scop, (digitaire), Setaria faberi Herrm, (sétaire). Setaria viridis (L.) Beauv., Seiaria viridis var. robusla-purpurea Schreiber ct Seiaria lutescens (Weigel) Hubb., (sétaires) a étéétudiéé en serre. vis-d-vis de I'atrazine. de la cyanazine, du butylate et de I'alachlore. Eriochloa villosa a été I'espéce la moins sensible aux herbicides essayds parmi lesquels I'alachlore s'est montré le plus efficace. La digitaire a été maitrisé par I'alachlore, le butylate et la cyanazine k toutes les doses essayees, mais pour I'atra-zine. seulement à des doses supérieures à 0.56 kg/ha. Ces quater herbicides ont donne des resultats acceptables contre le panic, et les sétaires (S. faberi, S. viridis, S. viridis var. robusta-purpurea, S. lutescens). La sensibilité des graminées à la cyanazine et à I'alachlore fut en corrélation avec la taille des semences. L'alachtore s'est montré plus efficace contre la sétaire S. viridis var. robusta-purpurea ct contre l'Eriochloa villosa quand il a été appliqué sur la surface du sol avant la levée que lorsqu'il a éié incorporé au sol avant le semis.Die Empfindlichkeit von sieben einjährigen Gräsern gegenüber Herbiziden.Es wurde die relative Empfindlichkeit von Digitaria sanguinalis (L.) Scop., Echinochloa erus-galli (L.) Beauv., Eriochloa villosa (Thumb.) Kunth-, Setaria faberi Herrm., Setaria lutescens (Weigel) Hubb., Setaria viridis (L.) Beauv. und Setaria viridis var. robusta-purpurea Schreiber gegenuber Atrazin, Cyanazin, Butylat und Alachlor unter Gewächs-hausbedingungen untersucht. Eriochloa him war gegenúber den gepruften Herbiziden am wenigsten empfindlich, Alachlor scliien die beste Wirkung zu haben. Digiiaria sanguinalis wurde durch Alachkir. Butylat und Cyanazin bei alien gepruften Aiifwandmengen bekampft, durch Atrazin aber nur bei Aufwandmengen ilber 0.56 kg/ha. Alte vier Herbizide ergaben eine brauchbare Bekampfung von Echinochloa crus-galli, Seiaria Jabcri, Seiaria viridis. Setaria viridis var. robusta-purpurea und Setaria luiescens. Die Emptindlichkeit der Gräser gegenüber Cyanazin und Alachlor stand in Beziehung zur Samengrösse. Alachlor bekämpfte Seiaria viridis und Erioehloa villosa im Vor-auflaufverfahren besser als im Vorsaatverfahren mit Ein-arbeitung.

Notes: The effectiveness of 122 herbicides in inhibiting growth of buds from single-node sections of couch (Agropyron repens (L.) Beauv.) rhizomes was evaluated under glasshouse conditions. Treatments were made by planting twenty-five couch rhizome segments in washed silica sand and watering them with nutrient solution containing from 10−2 to 10−8 M concentrations of the herbicides. Final evaluations were made 21 days after planting. At 10−5 M or lower concentrations, nineteen herbicides inhibited couch bud growth to less than 5 % of that in the untreated cultures. This concentration is approximately 0–28 kg/ha calculated on a 15-cm plough-slice basis. Herbicide groups showing the greatest inhibition of quackgrass rhizomes were the anilides and amides, carba-mates, and toluidines. Overall, pronamide (3,5-dichloro-N-(1,1-dimethylpropynyl)-benzamide) demonstrated the greatest activity. Many of the herbicides shown to be effective in this study do not generally control quackgrass under field conditions. Their lower activity in the field may be due to excessive decomposition, soil-herbicide interactions, or lack of rhizome exposure to the herbicides. Some herbicides which provide couch control under field conditions were not effective in this study. The reduced effectiveness of these chemicals under the conditions tested probably occurred because the herbicides were active only when applied post-emergence, because the primary action mechanisms were on processes other than bud development, or because the observation period was too short to detect complete results.Influence des herbicides sur le developpement des bourgeons du chiendentL'activité inhibitrice de la croissance des bourgeons de fragments de rhizomes de chiendent (Agropyron repens (L.) Beauv.) comportant un seul noeud, a étéévaluée en serre pour 122 herbicides. Les traitements ont été effectués en plantant 25 fragments de rhizome de chiendent dans un sable de silice Iavé et en leur apportant une solution nutritive contenant les herbicides k des concentrations allant de 10−2à 10−8 M. Les évaluations finales ont été faites 21 jours aprés la plantation. A la concentration a 10−5 M ou a des concentrations plus faibles, dix-neuf herbicides inhibérent la croissance des bourgeons de chiendent jusqu'a moins de 5 % de celle des cultures non traitées. Cette concentration correspond approximativement k un traitement à 0,28 kg/ha calculé sur la base d'un labour à 15 cm. Les groupes d'her-bicides manifestant la plus forte inhibition des rhizomes de chiendent furent les anilides, les amides, les carbamates et les toluidines. Le plus actif fut la pronamide (3,5-dichloro-N-(1,1-dimothylpropynil)-benzamide). Beaucoup des herbicides qui se montrerent efficaces dans cette étude ne l'etaient pas contre le chiendent au champ. Leur activité plus faible au champ peut été due k une decomposition excessive, k des interactions sol-herbicide, ou au défaut de contact entre les rhizomes et les herbicides. Quelques herbicides qui s'avfirent efficaces au champ contre le chiendent ne l'ont pas été dans cet essai. La réduction d'efficacité des produits dans les conditions de essaisest probablement manifest Se en raison du fait que les herbicides furent actifs seulement en traitements de post-levée, parce que les mocanismes d'action primaire s'exerecérent sur des processus autres que le développement des bourgeons, ou parce que la période d'observation fut trop courte pour detecter des résultats complets.Einfluss von Herbiziden auf die Knospenenlwicklung bei der QueckeEs wurde die Wirkung von 122 Herbiziden auf die Hemmung des Knospenwachstums von Rhizomabschnitten der Quecke (Agropyron repens (L.) Beauv.) mit jeweils einem Nodium, unter Gewachshausbedingungen untersucht. Die Behand-lungen wurden folgendermassendurchgefuhrt: 25 Abschnitte von Queckenrhizomen wurden in gewaschenen Quarzsand gepfianzt und mit Nahrlosung gegossen, die Herbizid in 10−2 bis 10−8 M Konzentration enthielt. Die endgultige Aus-wertungerfolgte 21 Tage nach dem Pflanzen. Bei 10−5 M oder niedrigeren Konzentrationen hemmten 19 Herbizide das Wachstum der Queckenknospen um weniger als 5% im Vergleich zu Unbehandelt. Diese Konzentration entspricht etwa einer Aufwandmenge von 028 kg/ha bezogen auf 15 cm Pfiugtiefe. Die grossteHemmwirkung gegenuber den Queckenrhizomen zeigten die Herbizide aus der Gruppe der Anilide, Amide, Carbamate und Toluidine. Insgesamt wies Pronamid (3,5-Dichlor-N-(1,1-dimethylpropinyl)-benzamid) die grosste Aktivitat auf. Viele der Herbizide, die unter den Versuchs-bedingungen wirksam waren, bekSaAmpfen die Quecke im Freiland gewöhnlich nicht. Die geringere Wirksamkeit dieser Herbizide im Freiland kann auf ubermessigen Abbau, auf Boden-Herbizide-Wechselbeziehungen oder auf fehlenden Kontakt des Rhizoms mit dem Herbizid zuruckzufuhren sein. Andererseits waren einige Herbizide, die eine Be-kampfung der Quecke unter Freilandbedingungen gewähr-leisten, in diesem Versuch nicht wirksam. Die verringerte Wirksamkeit diser Verbindungen unter den hier herrschenden Bedingungen, kann darauf zuruckgefuhrt werden, dass die Herbizide nur wirksam sind, wenn sie im Nachauflauf eingesetzt werden weil die primaren Wirkungsmechanismen an andere Prozesse als die Knospenentwicklung gebunden sind, Oder weil der Beobachtungszeitraum zu kurz war, um zu einer endgultigen Aussage zu gelangen.

Notes: Sprays (0·1 per cent) of bromophos or dioxathion afforded complete protection against both feeding ptmctures and mines of Phytomyza syngenesiae and could be used with parasites and predators. Other effective chemicals were azinphosr-methyl, bendiocarb, carbophenothion, cartap, dimethoate and pirimicarb.

Notes: Italian ryegrass, cultivars Aberystwyth S22 and perennial ryegrass, CV.S321, grown for the production of seed in the A.D.A.S. S.E. Region and Wiltshire were surveyed for ryegrass mosaic virus (RMV). Visual leaf symptoms were used to assess infection; the diagnosis was checked using the electron microscope.RMV infection was widespread in both grasses and about 30 per cent of the fields carried an infection level greater than 10 per cent (based on number of plants infected/examined). Higher levels of infection were encountered in crops of Italian ryegrass than in perennial ryegrass. Out of 69 fields of Italian ryegrass, only 12 showed no infection whilst nine fields showed a level of infection greater than 30 per cent. Twenty-eight of the 61 fields of perennial ryegrass showed no infection and the highest level of infection found was 26 per cent.All of the Italian and most of the perennial ryegrass crops were in their first harvest year. Since Italian ryegrass crops were occasionally encountered with more than 70 per cent of the plants infected, it is obvious that RMV can spread very quickly.In perennial ryegrass fields an increase in the amount of N fertilizer applied in the spring led to an increase in RMV; an increase from 100 to 200 kg N/ha led to an increase in the level of RMV from 9 to 37 per cent.By the first harvest year, fields sown in the spring of the previous year (usually under a cereal crop) were generally much more heavily infected than those sown in the autumn of the same year.