ALBERT

Notes: The effects of intensity, duration and spectral quality of light were investigated on the germination of Galium spurium L. Light inhibited germination and the degree of this inhibition was related to the intensity and duration of exposure to light beyond the initial 36-h imbibition period. Subsequent dry storage for up to 7 weeks and reincubation in the dark did not remove this inhibitory effect, indicating that a secondary dormancy was induced by continuous exposure to light. Germination was completely inhibited with intermittent 1-h exposures of light every 3, 7 or 11 h for 8 days. Red, far-red and blue light inhibited germination and the degree of inhibition was related to the duration of exposure. Far-red light was more inhibitory than red or blue light. Green light promoted germination slightly. Nitrate salts in the medium during light exposure did not prevent the onset of light-induced dormancy. In subsequent dark incubation, light-induced dormancy was overcome by the addition of nitrates and, to a lesser extent, by kinetin and GA3.

Notes: Barban was combined with benzoylprop ethyl, flamprop methyl, or flamprop isopropyl, and the eflects of the combinations on wild oat control and crop yield were assessed, tn greenhouse experiments, the interaction in all three combinations was synergistic, following application at the 2- or 4-leaf stage of wild oats. Under field conditions, combinations of barban + benzoylprop ethyl applied at the 2- or 4-leaf stage of wild oats were as eflective for wild oat control and wheat yield response as barban at 028 kg/ha applied at the 2-leaf or benzoylprop ethyl at 14 kg/ha applied at the 4-leaf stage of wild oats. Mixtures of barban + flamprop methyl applied at the 2- or 4-leaf stage of wild oats provided excellent wild oat control and wheat yield increases. Mixtures of barban + flamprop isopropyl applied at the 2- or 4-leaf stage of wild oats provided comparable wild oat control and barley yield increases to barban (028 kg/ha) applied at the 2-leaf or flamprop isopropyl (14 kg/ha) applied at the 4-leaf stage of wild oats.

Notes: Summary: Résumé: ZusammenfassungThe spray retention, foliar penetration and translocation of asulam [methyl (4 aminobenzenculphonyl) carbamate] by wild oats (Avena fatua L.) (Susceptible) and flax (Linum usitatissimum L.)(Tolerant) were examined in an attempt to elucidate the nature of differential sensitivity. Wild oat plants retained about four times as much spray solution of a commercial formulation of asulam as did flux. Penetration into flax was much more rapid than into wild oats. Added surfactant and high relative humidity greatly enhanced the penetration of the herbicide into wild oats. An increase in temperature from 10 to 30° C resulted in a large increase in penetration into both species. After foliar application of 14C-asulam the radioactivity was distributed throughout the wild oat plants. But the translocation in flax was very limited. Here most of it remained in the treated leaf, probably as a result of contact injury caused by the chemical No detectable qualitative or quantitative differences in the metabolism of asulam in the two species were found. Our studies suggest that spray retention, foliar penetration and translocation all play an important role in the selectivity of asulam between wild oats and flax. Rétention'de la pulvérisation, pénélration foliaire, migration el selectivity de I'asulamt chez la folle-avoine et Ie lin La rëtention de la pulvérisation, la pénétration foliaire et la migration de I'asusulame (4 aminobenzënesulfonyl carbamate de méthyle) not étéétudJiees chez la folle avoine (Avfna fatua L.) (sensible)ct chez le lin (Linum usitalissimum L) (resistant) pour tenter d'ëlucider la nature de la difference de scnsibilité. LES plantes de folle-avoine ont retenu quatre fois plus que le lin de la pulvérisation d'une formulation commercial d'asulame. La pénétration dans Ie lin a été beaucoup plus rapide que dans la folle-avoine. L'addition d'un agent de surface et one humidité relative êlevêe ont grandement favorisê la pênetration de I'herbicide dans la folle-avoine one élévation de la temperature de 10 à 30° C a provoqué one import ante augmenta tion de la pênêtration dans les deux espèces. Après one application foliaire d'asulame marqué au 14C. la radioactivité a été rêpartie dans l'ensemble de la plante chez la folle-avoine. mais la migration chez le lin a êtê três limitêe. La plus grande panie de cette radioactivitê est restêe dans la feuille traitèe. probablement en raison des damages provoquês par le contact duproduit. ll n'a pasêtêdecelê de differences, ni qualitatives. niquantitatives. Dans)le mêtabolisme de l'asulame chez les deux espêces. Nos recherches suggèrent que la retention de la pulvêrisation, la pénétration fotiaire et la migration jouent un röle important dans la sélectivité de l'asulame entre la folle-avoine et le lin. Spritzmitelrterenrntion, Blmprnetlration, Tronslokation and Selekrivitär von Asulam hei Flughafer and Flachs Spritzmittelretention. Blat penetration and Translokation von Asuiam [Methyl-l-aminobenzolsulfonyl)-carbamat] bei Flughafer (Avina fatua L.)empfindlich) and Flachs (Limum usiiaiis imum L.)(tolerant) wurden untersucht mit dem ziel. Aufklärung über die Ursache der unter Mhiedlichen Emptindlichkeit zu erhalten Flughaferpflanzen hielten etwa vicnnai so vicl Spritzmittellösung ciner handclsüblichen Asulamformulierung zurück wie Flachs. Die Penetration bei Flachs erfolgte vicl schnelier als bei Flughafer. Der Zusatz von oberflächenaktiven Stoffen and hohe Luftfeuchtigkeit erhöhten die Penetration des Herbizids bei Flughafer beträchtlish. Tcmperaturerhöhung von 10 auf 30°C führte bei beiden Pflanzenarten zu einer starken Zunahme der Penetration. Nach Blattapplikation von 14C-Asu lam war bei Flughafer die Radioaktivität über die gesamte Pflanze verleilt; bei Flachs dagegen fand nur eine sehr beschränkteTranslokation statt. Hier verblieb die meiste Radio aktivität im behandelten Blatt. was wahrscheinlich auf eine Schädigung durch Kontaktwirkung des Mittels zURÜCKZU führenist. Qualitative oder quantitative Unlerschiede im Metabolismus von Asulam in den beiden Pflanzen konnten nicht gefunden werden. Unscre Untersuchungen lassen vermuten. dass Spritzmittelretention. Biattpenetration and Translokation gemeinsam für die Selektivität von Asulam zwisehen Flughafer und Flachs eine wichiige Rolle spielen.

Notes: Excised soybean (Glycine max (L.) Merr.) hypocotyls, barley (Hordeum vulgare L.) coleoptiles, barley leaf sections, and Canada thistle (Cirsium arvense (L.) Scop.) leaf discs continuously absorbed 14C-picloram from a buffered solution over a 24 h period. After an 8 h uptake period excised sections released up to 30 % of the absorbed picloram into ‘clean’ buffer solution in a 4 h period. Leaf sections released less than did the other tissues. Uptake of 14C-picloram by soybean hypocotyl and barley coleoptile sections increased with an increase in temperature from 5 to 35°C. Uptake was promoted by added ATP and sucrose but inhibited by actinomycin D, cycloheximide, and DNP.After differential centrifugation of aqueous extracts of 14C-picloram-treated excised tissues more than 95 % of the radioactivity was in the soluble fraction.In excised barley and Canada thistle leaf tissues, 3 days after treatment, part of the 14C-picloram was conjugated with plant constituents, largely with sugar(s). After acid hydrolysis of ethanol extracts of such tissues only unaltered picloram was detected. In barley coleoptile and soybean hypocotyl sections no conjugation products of 14C-picloram were detected.