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1.
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. 相似文献
2.
O. R. SOUTHWOOD 《Weed Research》1971,11(4):231-239
In a field trial, different doses of five herbicides applied in autumn and late winder were compared for the control of barley grass (Hordeum leporium Link) in dryland Lucerne. Diuron at 1·1, 2·2, and 4·5 kg/ha and atrazine at 1·1 kg/ha were more effective in increasing Lucerne production than linuron at 4·5 kg/ha and various rates of dalapon and paraquat. Autumn application generally resulted in greater Lucerne production than late winter application. Most treatments reduced the amount of barley grass in the Lucerne. Diuron and atrazine also eliminated reduced the amount of barley grass in the Lucerne. Atrazine, diuron and linuron had a strong residual effect and reduced the density of subterranean clover and barley grass in the autumn following treatment. 相似文献
3.
Paul Gaillardon 《Pest management science》1996,47(4):347-354
Long-term sorption of diuron and isoproturon by a clay loam soil was investigated for nine weeks at two herbicide doses (0·6 or 3 mg kg−1) and two soil moisture contents (35 or 62% w/w, i.e. 3·16 or 1 kPa) by measuring changes in herbicide concentrations in the soil solution sampled by means of glass microfibre filters in presence of sodium azide (200 mg litre−1) which inhibited biodegradation for more than four weeks. After the first day equilibration period, where adsorption mainly occurred (>70% adsorbed), herbicide concentrations in the soil solution decreased (about 50% for diuron; up to 38% for isoproturon) for two weeks but equilibration required about one month. Small amounts of herbicides were sorbed during this process (<10% of the initial (24-h) adsorption). These were similar for both herbicides, although diuron was initially more adsorbed. Values of the partition coefficients of herbicides between soil and soil solution were increased (75–125% for diuron; 29–67% for isoproturon). High soil moisture enhanced sorption speed for both herbicides and increased final sorption only for diuron. Sodium azide inhibited long-term sorption of the more stable diuron and this effect was reversed by low temperature only at the low soil moisture. Sodium azide action might be complex (competition, effect on soil micro-organisms) and was not elucidated. 相似文献
4.
M. HOROWITZ 《Weed Research》1969,9(4):314-321
Summary. The persistence of ten herbicides in soil was tested in the glasshouse over a 5–month period, using an oat bioassay. Simazine and diuron were highly persistent, atrazine persistent, fluometuron, trifluralin, bromacil and noruron moderately persistent, and pyrazon, prometryne and ametryne of short persistence. Six of these herbicides were also included in a field experiment consisting of logarithmically sprayed strips on which oats were sown at ten intervals of 1 month; changes of herbicidal activity with time were evaluated by measuring the length of the strip showing herbicidal injury. Results corroborate those of the glasshouse experiments except for trifluralin which was more persistent in the field. Disappearance curves were generally sigmoidal. The more persistent compounds showed a long period of slow disappearance followed by rapid disappearance. 相似文献
5.
Summary. The metabolism of [14C]fluometuron in Citrus was studied by feeding the herbicide to either young seedlings or to excised organs. Most of the uptake of fluometuron occurred via the roots during the first 24 h and radioactivity was found after 16 days to be in the rootlets (36·5%), mainroot (34·5%), stem (13·7)% and leaves (15·2%). By feeding [14C]fluometuron to excised organs it was established that although most of the fluometuron breakdown occurred in the rootlets, other plant parts were also capable of metabolizing the herbicide. Therefore, the presence of metabolites in the upper plant organs was not entirely due to translocation from the rootlets. These results suggest that the resistance of Citrus to fluometuron is due to its breakdown in the tissues, probably induced by an N-demethylase enzyme system, similar to that reported for cotton (Frear, Swanson & Tanaka, 1969), in which harmless metabolites arc formed. Détoxification du fluométuron par les tissus de Citrus 相似文献
6.
Glasshouse studies showed that low doses of paraquat inhibited the germination of Lolium perenne L. broadcast directly onto the paraquat-sprayed surfaces of a sphagnum and a peat soil, but that higher doses were necessary to produce phytotoxic symptoms on mineral soils, a compost and a loam. On all soils residual activity increased rapidly with increasing dose once the minimum phytotoxic dose was reached. On a sandy soil, residual activity increased almost linearly from the lowest to the highest dose applied. At 9·0, 4·5 and 2·24 kg/ha phytotoxicity on a compost was not affected by changes in the volume of application, but at 1·68 kg/ha and lower, reducing the volume from 562 1/ha to 281 and 112 1/ha resulted in increased phytotoxicity. Phytotoxic residues were eluted from paraquat-treated compost surfaces by percolating de-ionized water up soil columns but residual activity was not removed from the eluted surfaces. Surface irrigation of paraquat-treated surfaces with water previously percolated through columns of untreated soil reduced residual activity by 45%. 相似文献
7.
A.A.S. IBRAHIM 《Weed Research》1984,24(4):227-231
Losses of about 40% in cane yields due to natural stands of weeds were found in experiments conducted in sugarcane var. Co 527 in the year of planting at Guneid Sugarcane Research Station, Sudan. Weed competition lowered millable stalks per metre row by 32%, stalk height by 24%, stalk thickness by 15% and number of nodes per stalk by 14%. Tillering was the growth phase most affected by weed competition. Cane yields were increased as number of hand weedings increased, but four weedings were not markedly better than three. The average yield (67·04 t ha?1) obtained from four weedings was not significantly (P= 0·05) better than that of three weedings carried out at 3, 6 and 9 weeks after cane planting. Juice analysis components were also affected by weeds and a 15% reduction in sucrose recovery was recorded. Reductions in the other components were only 4–7%. Atrazine and diuron (3·3 kg ha?1), metribuzin (2·4 kg ha?1) and metribuzin (1·3 kg ha?1) in tank mixture with diuron (1·5 kg ha?1) gave excellent residual weed control of the dominant weed species, Ipomoea cordofana Choisy., Brachiaria eruciformis (Sm.) Griseb., Corchorus fascicularis Lam., Ocimum basilicum L. and Dinebra retroflexa (Vahl) Panz., for most of the first growing season. Excellent control of weeds achieved by the herbicide treatments resulted in comparable yields to frequently-weeded cane. These herbicides were not phytotoxic to sugarcane var. Co 527. 相似文献
8.
Diuron and fluometuron at 0–6 kg/ha and propham at 4 kg/ha were sprayed on the soil surface and left exposed for 2 weeks to hot and sunny weather. All three herbicides were completely deactivated when sprayed on wet soil; on air-dry soil a smaller but appreciable loss of diuron and propham was recorded. Shallow incorporation after spraying on dry soil reduced greatly the dissipation. A light irrigation after spraying or after 1 week of exposure increased the loss of the herbicide. Conditions du sol affectant la disparition du diuron, du fluomituron et du prophame de la surfaee du sol Le diuron et le fluométuron à 0,6 kg/ha et le propham à 4 kg/ha ont été appliqués en pulvérisation à la surface du sol et laissés exposés pendant deux semaines à la chaleur et à un temps ensoleillé. Les trois herbicides ont été complétement inactiveés lorsqu'ils ont été appliqués sur un sol humide; sur un sol séchéà l'air, il a été enregistrée une perte faible mais appréciable, de diuron et de prophame. Une incorporation superficielle aprés la pulvérisation sur un sol sec réduisit beaucoup la dégradation. Une irrigation légére aprés la pulvérisation ou aprés une semaine d'exposition augmenta la perte d'herbicide. Bodenverfidltnisse, die den Verlust von Diuron, Fluometuron und Propham eon der Bodenoberflache bedingen Diuron und Fluometuron wurden mit 0–6 kg/ha und Propham mit 4 kg/ha auf die Bodenoberfläche gespritzt, wo sie zwei Wochen lang, heissem und sonnigem Wetter ausgesetzt waren. Wurde auf nassen Boden gespritzt, dann wurden alle drei Herbizide vollständig desaktiviert; bei lufttrockenem Boden wurde ein geringer, aber deutlicher Verlust vonDiuron und Propham beobachtet. Flache Einarbeitung nachder Spritzung erniedrigte bei trockenem Boden den Verlust sehr. Leichte Beregnung nach dem Spritzen, oder eine Woche nach dem die Herbizide an der Bodenoberflache dem Wetter ausgesetzt waren, erhöhte den Herbizidverlust. 相似文献
9.
Localized placement of prometryne, linuron and diuron in the soil at the first or second shoot internodes of dwarf broad bean (Vicia faba L.) equally reduced aerial plant growth, whereas simazine and atrazine had no effect. Growth reduction also occurred when the first shoot internode of scarlet runner bean (Phaseolus multiflorus L.) in the soil was treated with all five herbicides, especially with diuron. Localized placement of these herbicides at the first or second shoot internodes of vetch (Vicia sativa L.) in the soil equally reduced aerial plant growth. Foliar injury to vetch due to placement of these herbicides in the shoot zone of the soil was markedly reduced by simultaneous treatment with trifluraiin or nitralin which prevented adventitious root development on the shoot without otherwise affecting plant growth. This lack of root development on the shoots treated with trifluraiin was associated with a marked decrease in 14C-labelled atrazine uptake, which probably accounted for the reduction in atrazine phytotoxicity. A similar explanation may account for the reduced phytotoxicity of the other herbicides in the presence of trifluraiin or nitralin. 相似文献
10.
Fruit harvested from gooseberry plots treated with up to 33·6 kg/ha of chlorthiamid and dichlobenil (applied at two dates) was examined for the presence of residues of 2,6-dichlorobenzonitrile together with the possible metabolites, 2,6-dichlorobenzamide and 2,6-dichlorobenzoic acid. In addition the canned fruit was examined for taint. Residues of 2,6-dichlorobenzonitrile resulting from the application of both herbicides at all rates were below 0·05 ppm. Residues of 2,6-dichlorobenzamide ranged from 0·13 to 0·45 ppm with the greatest residues occurring in fruit from plots treated with the highest amounts of chlorthiamid in March. Fruit from some of the March applications of both herbicides contained residues of up to 0·16 ppm 2,6-dichlorobenzoic acid. No taints were found in the canned fruit. 相似文献
11.
P. B. MARRIAGE 《Weed Research》1975,15(5):291-298
Atrazine, simazine, diuron, and linuron applied to soil increased the percentage moisture of oat (Avena sativa L.) shoots in bioassays at the lowest dose tested of 0·25 ppm. Further increases occurred up to 2 ppm but at higher concentrations the percentage moisture decreased. At all doses of each herbicide, shoot dry weight was decreased. In oats grown on soil collected from a peach orchard which had received repeated annual applications of these herbicides, the percentage moisture of the oat shoots was higher than the control value whenever the oat dry weight was decreased and provided a method of residue detection as sensitive as dry weight measurements. Treatment of oats by soil application of the above herbicides in bioassays also caused increases in the electrical conductivity of an aqueous extract of the oat shoots per mg of dry weight and this characteristic was slightly more sensitive than dry weight in detecting herbicides in orchard soil. The conductivity of the extract per mg of water in the shoots, however, only increased as percentage moisture decreased. The weight of neutral water-soluble material in oat shoots decreased much more rapidly than dry weight in bioassays with standard herbicide concentrations. Determination of the weight of neutral water-soluble material in oat plants grown on orchard soil samples indicated the presence of herbicide residues in 50% of the cases in which residues were not detectable by dry weight. The weight of neutral material as a percentage of dry weight was almost as sensitive. Chemical analysis of soil in which oat plants had a decreased level of neutral water-soluble compounds indicated that this characteristic had a lower limit of detection for herbicide residues of approximately 0.10 ppm. 相似文献
12.
Y. KLEIFELD B. RUBIN T. BLUMENFELD G. HERZLINGER H. BUXBAUM S. GOLAN 《Weed Research》1994,34(6):461-469
Mechanical incorporation of a tank mixture of trifluralin in combination with fluometuron, diuron or prometryne in the soil to a depth of 10 cm protected emerging cotton from the damage caused by these herbicides in the absence of trifluralin. The incorporated tank mixtures, which were activated by sprinkler irrigation, controlled weeds which were tolerant to trifluralin alone. The different reaction of weeds and cotton to the soil-incorporated herbicide mixtures corresponded to the reaction of their root systems to trifluralin. Weeds whose root system was shortened significantly by trifluralin were sensitive to the tank-mixed, soil-incorporated herbicides. La trifluraline incorporée au sol protége le coton (Gossypium hirsutum) des herbicides à absorption racinaire L'incorporation mécanique de mélanges de trifluraline avec du fluométuron, du diuron ou de la prométryne, à des profondeurs de sol 10 cm, protégeait le coton au moment de la levée contre les dommages occasionnés par ces herbicides en l'absence de trifluraline. Les mélanges incorporés, quiétaient activés par irrigation par aspersion, détruisaient les mauvaises herbes qui étaient tolérantes à la trifluraline seule. La réaction différente des mauvaises herbes et du coton aux mélanges d'herbicides incorporés correspondait à la réaction de leur système racinaire à la trifluraline. Les mauvaises herbes dont le systéme racinaire était raccourci par la trifluraline étaient sensibles aux mélanges d'herbicides incorporés. Schutz der Baumwolle (Gossypium hirsutum) vor wurzelabsorbierten Herbiziden durch eingearbeitetes Trifluralin Nach Einarbeitung von Tankmischungen von Trifluralin mit Fluometuron, Diuron oder Prometryn bis in 10 cm Bodentiefe blieben Baumwoll-Keimpflanzen von den sonst von diesen 3 letzgenannten Herbiziden verursachten Schaden frei, Mittels der Tankmischungen ließen sich gegenuber Trifluralin allein unempfindliche Unkrauter bekampfen. Die unterschiedliche Reaktion der Unkrauter und der Baumwolle auf die eingearbeiteten Herbizidmischungen entsprachen der Reaktion ihrer Wurzeln auf Trifluralin. Soweit die Entwicklung von Unkrautwurzeln durch Trifluralin signifikant gehemmt wurde, waren diese Arten gegenuber den eingearbeitenen Tankmischungen empfindlich. 相似文献
13.
D. HAWTON 《Weed Research》1980,20(1):25-31
The effects of several selective herbicides, combinations of diuron with activated carbon, slashing and stale seed bed treatments were tested in five field experiments conducted at Walkamin, Queensland, Australia to determine the best methods of controlling weeds, particularly the legume Crotalaria goreensis Guill. & Perr., in crops of Macroptilium atropurpureum (DC.) Urb. cv. Siratro, grown for seed. Alachlor alone and combinations of trifluralin with either alachlor or propachlor were effective in preventing weeds causing a yield reduction in one experiment but not in a second. Trifluralin plus propachlor was more effective in controlling broad-leaved weeds while trifluralin plus alachlor was more effective in controlling grasses. Activated carbon effectively protected M. atropurpureum from diuron damage but the control of weeds, particularly grasses, was not effective. Stale seed bed treatments involving three sequential applications of diquat prior to planting the crop was the most effective method of controlling C. goreensis. 相似文献
14.
The phytotoxicity of five soil-acting herbicides was investigated in two sandy loam soils and that of a further five herbicides in one of these soils. The effect of liming on phytotoxicity was also examined. Metoxuron, fenuron, metribuzin and fluometuron were more active in Boddington Barn soil than in Bledington soil. Prometryne was similar in effect in both soils. Liming significantly increased the effect of metoxuron in Boddington Barn soil and metoxuron, atraton, difenoxuron and metribuzin in Bledington soil. Monolinuron was less toxic in limed Bledington soil. Reasons for these differences have not been determined. 相似文献
15.
Summary. Herbicide combinations containing paraquat were synergistic and provided control of established Agropyron repens (L.) Beauv. (quackgrass) sods for the entire growing season. Paraquat applied at 0–5 lb/ac with simazine or diuron at 4–0 lb/ac was more phytotoxic than either herbicide applied singly and the enhanced activity was more than additive. This synergism was not due to increased absorption or translocation of either herbicide in aerial portions of the plant. Paraquat applied to the shoot increased the susceptibility of quackgrass to simazine action through the soil. Pre-treatment of quackgrass with aminotriazole or amitrole-T at 10 lb/ac 7 days before paraquat application at 0–5 lb/ac provided increased toxicity over that obtained when the two herbicides were applied together or singly. Subsequent studies indicated that aminotriazole applications prior to shoot destruction by either paraquat or clipping resulted in more chronic aminotriazole toxicity. Using methyl-14C-paraquat it was found that aminotriazole pre-loading also increased the movement of paraquat in and out of the treated leaf. This increase was even more pronounced with amitrole-T. When the two herbicides were applied together, antagonism in absorption and translocation occurred. Action synergique de combinaisons d'herbicides comprenant du paraquat sur Agropyron repens (L.) Beauv. 相似文献
16.
Reduced rates of residual and post-emergence herbicides for weed control in vineyards 总被引：1，自引：0，他引：1
In 1997 and 1998, five field studies were conducted at four Portuguese wine‐growing regions in order to evaluate the effectiveness of the chemical control of vineyard weeds under Mediterranean conditions using either reduced doses of residual herbicides or only foliar herbicides. Amitrole (3440 g a.i. ha?1), amitrole + glyphosate mono‐ammonium salt (1720 + 900 g a.i. ha?1), amitrole (3400 g a.i. ha?1), amitrole + diuron (2580 + 1500 g a.i. ha?1), amitrole + simazine (2580 + 1500 g a.i. ha?1), amitrole + terbuthylazine (2580 + 1500 g a.i. ha?1) and amitrole + diuron + simazine (2580 + 1300 + 1400 g a.i. ha?1) were assayed and compared with the following reference herbicides: glyphosate isopropylamine salt (1800 g a.i. ha?1), amitrole + diuron (2520 + 1680 g a.i. ha?1), diuron + glyphosate + terbuthylazine (1275 + 900 + 1425 g a.i. ha?1), amitrole + simazine (1900 + 3900 g a.i. ha?1) and glyphosate + simazine (800 + 2200 g a.i. ha?1). The herbicides were applied during late winter. The results indicated that good control was achieved by the application of foliar herbicides alone or of reduced rates of a mixture of residual herbicides with foliar herbicides for at least 2 months. Three months after application, the efficacy of post‐emergence herbicides and lower rates of residual herbicides decreased significantly in clay soils and under heavy rainfall conditions. Convolvulus arvensis– a weed that is becoming increasingly significant in Portuguese vineyards – was poorly controlled, even when glyphosate was used. Despite this, it can be assumed that in those regions in which the trials were conducted, it is possible to employ weed control strategies that entail the elimination or a reduction in the rate of residual herbicides. 相似文献
17.
Summary. Six sugarcane varieties, N: Co 310, F146, F148, F152, F153 and F156, were Found in a field trial to differ in their tolerance to pre-emergence diuron with units of susceptibility of 100, 1·57, 1·20, 1·60, 11·30 and 8·07, and to pre-emergence atrazine of 0·75, 0·97, 0·59, 1·44, 2·42 and 0·78 respectively. Relative tolerance was assessed by subjecting each variety to seven rates of the herbicides in geometric series and calculating the F values for monthly measurements of the cane plants through the growing seasons of both the autumn-planting and ratoon crops. Units of susceptibility of each variety were obtained by transforming each mean F value into a proportion of the value for the standard variety N: Co 310. Any residual effect of the pre-emergence herbicides even at 20 kg/ha a.i. on cane plants was found to be small and insignificant after ploughing field ridges 5 months from cane-planting. With diuron, increasing the rate up to 10 kg/ha began to cause a significant reduction of sugar yield per hectare of cane, while atrazine gave such a reduction only with 20 kg/ha. Détermination de la résistance variétale de la canne à sucre à l'éigard du diuron et de l'atrazine appliqués en pré-levée Résumé. Six variétés de canne à sucre, N:Co 310, F146, F148, F152, F153 et F156, ont manifesté dans un essai au champ des differences de résistance au diuron en pré-levée, avec des mesures de sensibilité de 1,00, 1,57, 1,20, 1,60, 11,30 et 8,07; pour l'atrazine en pré-levée, 0,75, 0,97, 0,59, 1,44, 2,42 et 0,78 respectivement. Une résistance relative fut établie en soumettant chaque variétéà sept doses des herbicides en progression géométrique et en calculant les valeurs de F pour des mensurations mensuelles des plantes de canne, durant la saison de croissance, à la fois pour les plantations d'automne et les repousses de cannes après recépage. Des unités dc sensibilité pour chaque variété furent obtenues en transformant chaque valeur moyenne de F en une proportion de la valeur pour la variety standard N:Co 310. L'effet résiduel des herbicides appliqués en pré-levée, même à 20 kg/ha (m.a.) sur les piantes de cannes fut faible et non significatif apres labour des billons à 5 mois de la plantation des cannes. Avec le diuron l'aecroissement de la dose jusqu’à 10 kg/ha provoqua un commencement de réduction significative de rendement en sucre par hectare, alors que l'atrazine provoqua une telle reduction seulement avec 20 kg/ha. Bestimmung der unterschiedlichen Toleranz von Zuckerrohrsorten gegenüber Diuron und Atrazin bei Vorauflaufbehandlung Zusammenfassung. Im Feldversuch wurde gefunden, dass die sechs Zuckerrohrsorten N: Co 310, F 146, F 148. F 152, F 153 und F 156 sich bei Vorauflaufbehandlung in ihrer Toleranz gegenüber Diuron und Atrazin unterscheiden. Die Suszeptibilitätseinheiten waren für Diuron 1,00, 1,57, 1,20, 1,60, 11,30 und 8,07, für Atrazin 0,75, 0,97, 0,59, 1,44, 2,42 und 0,78. Die Ermittlung der relativen Toleranz erfolgte, indem jede Sorte mit sieben Aufwandmengen der Herbizide in geometrischer Reihe behandelt wurde und die F-Werte für die monatlichen Messungen der Zuckerrohrpfianzen während der Vegetationsperiode berechnet wurden. Die Messungen erfolgten sowohl an im Herbst gepflanztem Zuckerrohr als auch an Wurzelschossen. Die Einheiten der Suszeptibilität für jede Sorte wurden durch Umformung eines jeden mittleren F-Wertes in einen auf die Standardsorte N: Co 310 bezogenen Relativwert erhalten. Die Wirkung von Rücks-tänden der Vorauflaufherbizide auf die Zuckerrohrpflanzen war selbst bei 20 kg/ha Wirkstoff nach Furchenpflügen 5 Monate nach der Auspflanzung gering und nicht signifikant. Diuron begann eine signifikante Minderung des Zuckerertrages pro Hektar hervorzurufen, wenn die Aufwandmenge bis auf 10 kg/ha gesteigert wurde, wahrend Atrazin erst bei 20 kg/ha eine solche Ertragsminderung verursachte. 相似文献
18.
P. WALLNÖFER 《Weed Research》1969,9(4):333-339
Summary. The decomposition of seven urea herbicides by Bacillus sphaericus was studied. Experiments with 14 C-labelled monolinuron demonstrated that monolinuron was degraded by removal of CO2 from the ureido portion of the molecule and leaving the /Kchloroaniline moiety. Tests with monuron, diuron, monolinuron, linuron, metobromuron, fluometuron and methabenzthiazuron indicated that B. sphaericus was only able to decompose the methoxy compounds monolinuron, linuron and metobromuron in this way. All compounds were identified by infrared spectroscopy. A pathway for degradation of the herbicides by B. sphaericus is proposed. 相似文献
19.
A procedure is described for the colorimetric determination of promecarb as 3-methyl-5-isopropylphenol in tissues using 2,6-dichlorpbenzoquinone-4-chlorimine as the chromogen. Cattle were exposed to either 1, 3, 5 or 8 spray applications of a 0·2% promecarb emulsion at 3-day intervals or were fed promecarb at 2 ppm or 20 ppm daily in the diet for 20 days. All animals were slaughtered 30 h after final exposure. Of the animals in the spraying trial, residues in omental fat ranged from 0·9 ppm to 1·5 ppm promecarb and 0·4 ppm to 1·9 ppm 3-methyl-5-isopropylphenol. Residues in perirenal fat ranged from 0·8 ppm to 1·9 ppm promecarb and 0·9 ppm to 1·6 ppm 3-methyl-5-isopropylphenol. Residues in diaphragm muscle did not exceed 0·06 ppm. In the feeding trial, the maximum residues induced were 2·2 ppm promecarb and 1·4 ppm 3-methyl-5-isopropylphenol in omental fat of an animal fed for 20 days on a diet containing 20 ppm promecarb. 相似文献
20.
J. M. GARCIA-BAUDIN A. R. LANSAC L. AYERBE† J. L. TENORIO† E. CADAHIA 《Weed Research》1985,25(5):319-322
Some substituted urea herbicides (chlortoluron, diuron and methabenzthiazuron) were tested for possible use in the cultivation of Euphorbia lathyris L. Diuron showed high phytotoxicity for this species, which was tolerant to chlortoluron and methabenzthiazuron. In preliminary experiments two triazine herbicide (atrazine and simazine) were also used, but both were so toxic to E. lathyris that their use was not continued beyond this stage. In glasshouse experiments, chlortoluron showed slight phytotoxicity to E. lathyris but this did not appear in field experiments. Both chlortoluron and methabenzthiazuron were very efficient against weeds which were present and significantly increased yield of E. lathyris in comparison with unweeded plots. The poor competitive ability of E. lathyris against weeds was confirmed. 相似文献