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1.
MCPA is antagonistic to a range of herbicides but there is limited research on its compatibility with other broad-leaved weed herbicides. In this study we assessed the joint action of MCPA ester and metsulfuron-methyl on Brassica napus L. using the additive dose model (ADM). The fresh weight responses for selected ratios of the mixture were plotted on the ADM and compared to the predicted mixture response at three assessment levels - 50, 75 and 90% control. The mixture demonstrated increasing synergism as the response level increased from 50 to 90%. This result for MCPA ester is in marked contrast to that of the MCPA amine formulation, which was shown in previous studies to be antagonistic towards sulfonylurea herbicides. Formulation is the major deciding factor in determining the compatability of phenoxy herbicides with other herbicides. 相似文献
2.
In growth chamber experiments, tralkoxydim activity against Avena fatua was significantly reduced by addition of metsulfuron methyl to the spray solution. This was apparent particularly at low rates of tralkoxydim (e.g., 125 g a.i.ha?1) and at high rates of metsulfuron methyl (8 or 12 g a.i. ha?1). Metsulfuron methyl alone reduced A. fatua growth significantly, Chlorsul-furon, which did not reduce A. fatua growth at rates of up to 33 g a.i. ha?1, caused only a slight loss in tralkoxydim activity. When applied in combination, metsulfuron methyl reduced the uptake of foliar-applied 14C-tralkoxydim 6 h after application, but did not affect uptake or translocation of 14C-tralkoxydim at subsequent sampling times. In in vitro assays, metsulfuron methyl at 10 or 100 nM in the assay medium had no effect on acetyl-coenzyme A carboxylase (ACCase) activity in A.fatua, nor did it interfere with the inhibition of ACCase by tralkoxydim. In addition, treatment of A. fatua plants with metsulfuron methyl at 4, 8 or 12 g ha?1 did not reduce the level of extractable ACCase activity when the plants were harvested 24–96 h after spraying. Thus, no apparent physiological or biochemical basis for the antagonism of tralkoxydim was identified. The temporary growth inhibition induced by metsulfuron methyl may be of sufficient duration for most of the tralkoxydim to be metabolized to inactive products, thereby reducing tralkoxydim-induced injury. Antagonisme entre le metsulfuron-methyl et l'activité de la tralkoxydime sur Avena fatua Dans des essais en chambres climatiques, l'activité de la tralkoxydime contre Avena fatua a été significativement réduite par l'adjonction de metsulfuron-methyl dans la bouillie de pulvérisation. Ceci est particulièrement apparent à de faibles doses de tralkoxydime (ex. 125 g. m.a. ha?1) et à de faibles doses de metsulfuron-methyl (8 à 12 g m.a. ha?1). Le metsulfuron-methyl seul réduit la croissance d'Avena fatua. Le chlorsulfuron qui ne réduit pas la croissance d'Avena fatuaà des doses jusqu'à 33 g m.a. ha?1 cause seulement une faible perte d'efficacité chez la tralkoxydime. Quand il est appliqué en mélange, le metsulfuron-méthyl a réduit l'absorption de la C14 tralkoxydime appliquée sur les feuilles 6 h après l'application, mais n'a pas affecté l'absorption et le transport de la C14 tralkoxydime aux autres temps d'échantillonage ultérieurs. Dans les essais in vitro, le metsulfuron-methyl à 10 ou 100 nm dans le milieu d'essai n'a pas eu d'effet sur l'activité de l'acetyl coenzyme A carboxylase (ACCase), ni n'a interféré avec l'inhibition de l'ACCase par la tralkoxydime. En outre, le traitement d'Avena fatua avec du metsulfuron-methyl a 4, 8 ou 12 g ha?1 n'a pas réduit le niveau d'activité d'ACCase quand les plantes étaient récoltées de 24 à 96 h après l'application. Ainsi aucune base apparente physiologique ou biochimique pour l'antagonisme de la tralkoxydime n'a été identifiée. L'inhibition temporaire de la croissance induite par le metsulfuron-methyl peut être d'une durée suffisante pour que la plus grande partie de la tralkoxydime soit métabolisée en produits inactifs, et de ce fait réduit les effets induits par la tralkoxydime. Antagonismus von Metsulfuron-methyl auf die Wirkung von Tralkoxydim auf Avenua fatua In Phytotron-Versuchen wurde die Wirkung von Tralkoxydim auf Avena fatua durch Zugabe von Metsulfuron-methyl in die Spritzbrühe signifikant herabgesetzt, besonders bei niedrigen Tralkoxydim-Dosen (z. B. 125 g AS ha?1) und bei hohen Metsulfuron-methyl-Dosen (8 oder 12 g AS ha?1). Metsulfuron-methyl allein setzte das Wachstum von Avena fatua signifikant herab. Mit Chlorsulfuron, das das Wachstum von Avena fatua bis 33 g AS ha?1 nicht verminderte, ließ sich die Wirkung von Tralkoxydim nur wenig beeinträchtigen. In Kombination reduzierte Metsulfuron-methyl die Blattaufnahme von 14C-Tralkoxydim 6 h nach der Applikation, aber bei späteren Probennahmen waren Aufnahme und Translokation von 14C- Tralkoxydim nicht beeinträchtigt. In In-vitro-Versuchen blieben 10 oder 100 mm Metsulfuron in der Versuchslösung ohne Wirkung auf die Aktivität der Acetyl-Coenzym-A-Carboxylase (ACCase) in Avena fatua, es wirkte auch nicht auf die Hemmung der ACCase durch Tralkoxydim. Auch eine Behandlung von Avena-fatua-Pflanzen mit 4, 8 oder 12 g AS ha?1 Metsulfuron-methyl setzte nach 24 bis 96 h die ACCase-Aktivität nicht herab. So konnte keine offensichtliche physiologische oder biochemische Basis für den Antagonismus von Tralkoxydim gefunden werden. Die durch Metsulfuron-methyl induzierte zeitweilige Wuchshemmung kann lang genug sein, daß das meiste Tralkoxydim zu inaktiven Produkten abgebaut wird, so daß seine Wirksamkeit reduziert wird. 相似文献
3.
Control of Avena fatua (L.) (wild oat) with diclofop methyl applied at 0·7 kg ha?1 at the two-leaf stage and difenzoquat at 0·84 kg ha?1 at the four-leaf stage in wheat (Triticum aestivum L.) under field conditions was good and not affected when either of these herbicides was mixed with 3,6-dichloropicolinic acid as the monoethanolamine salt at 0·14, 0·20 or 0·30 kg ha?1. In the glasshouse, mixtures containing 3,6-dichloropicolinic acid at rates as high as 0·6 kg ha?1 also did not affect control of A. fatua. When barban at 0·35 kg ha?1, or flamprop methyl at 0·56 kg ha?1 was mixed with similar rates of 3,6-dichloropicolinic acid and applied at the two-leaf and four-leaf stage of A. fatua respectively, a reduction in control of A. fatua (antagonism) occurred under both field and glasshouse conditions. The herbicides for control of A. fatua did not influence the fresh weight suppression of C. arvense shoots obtained in the glasshouse with 3,6-dichloropico-colinic acid at 0·3 kg ha?1. Early tolerance of wheat (cv. Neepawa) was acceptable with all mixtures. Wheat yields with diclofop methyl or difenzoquat alone or in mixture with 3,6-dichloropicolinic acid were increased over the yields from the A. fatua-infested control. 相似文献
4.
M. ANDREWS 《Weed Research》1990,30(5):331-340
Avena saliva cv. Amuri and A. fatua were sprayed with diclofop methyl (1.0 kg a.i. ha?1) alone and in combination with 2,4-D (1.1 kg a.i. ha?1), bentazone (1.0 kg a.i. ha?1), chlorsulfuron (15 g a.i. ha?1) or dicamba (0.3 kg a.i. ha?1). Effects of the herbicides on leaf extension rate during the first 8 to 10 days after spraying and subsequent growth (dry weight) after 57–75 days were determined by comparison with unsprayed plants. Diclofop-methyl applied alone did not cause a decrease in leaf extension rate of A. saliva or A. fatua until at least 4 days after spraying. All broadleaf weed herbicides in combination with diclofop-methyl caused a decrease in leaf extension rate of both species within 2 days of spraying. Ten days after spraying, leaf extension rates for plants sprayed with a broadleaf weed herbicide plus diclofopmethyl (all combinations) were lower than for unsprayed plants but greater than for plants sprayed with diclofop-methyl alone. With the exception of A. fatua sprayed with bentazone, long-term growth of plants sprayed with a broadleaf weed herbicide plus diclofop-methyl (all combinations) was lower than for unsprayed plants but greater than for plants sprayed with diclofop-methyl alone. Bentazone applied with diclofop-methyl caused a substantial decrease in leaf extension rate of A. fatua within 24 h of spraying but at harvest, dry weight of plants from this treatment was similar to or less than that for plants sprayed with diclofop-methyl alone. Application of diclofop-methyl with bentazone at a rate of 0.3 kg a.i. ha?1 also caused a reduction in leaf extension rate of A. fatua within one day of spraying. At this rate of bentazone, dry weight of plants at harvest was intermediate to that of unsprayed plants and those sprayed with diclofop-methyl alone. It is proposed that decreased leaf expansion rate during the first few days afte spraying is the cause of broadleaf weed herbicide antagonism of diclofop-methyl. 相似文献
5.
P. A. O'SULLIVAN 《Weed Research》1981,21(5):211-217
Linuron (0.21 and 0.28 kg/ha) and linuron + MCPA (0.21+0.56 kg/ha) in a tank mixture with field rates of barban, difenzoquat and flamprop-methyl reduced the phytotoxicity of these herbicides to Avena fatua. When linuron was applied immediately following or 6 days after the A. fatua herbicides no reduction in phytotoxicity to A. fatua occurred, suggesting that the antagonism may be occurring as a result of physical or chemical incompatability when the herbicides are mixed together. The possibility of obtaining broad-spectrum weed control with one trip over the field by applying linuron and one of these wild oat herbicides separately but at the same time using a double-boom, double-tank system deserves evaluation. When linuron was applied in a tank mixture (0.21 and 0.28 kg/ha), immediately after, or 6 days after diclofop-methyl (0.70 kg/ha), there was no reduction of A. fatua control, and wheat tolerance to the tank mixture was good. This tank mixture offers potential for control under field conditions of A. fatua and some broad-leaved weeds in one spray operation. Linuron + MCPA (0.21+0.56 kg/ha) in a tank mixture severely reduced A. fatua control with diclofop-methyl. No loss of phytotoxicity to Fagopyrum tataricum occurred when the A. fatua herbicides tested were tank mixed with linuron or linuron + MCPA. Lutte contre Avena fatua et Fagopyrum tataricum avec des mélanges extemporanés de linuron ou de linuron + MCPA et des applications successives de linuron et d'herbicides de postlevée actifs contre A. fatua 相似文献
6.
A series of eleven field experiments over two seasons investigated the control of Galium aparine (cleavers) with mecoprop and a proprietary mixture of ioxynil plus bromoxynil. Applications of mecoprop (2?4 kg a.e. ha?1) between December and March gave variable results but a mixture of ioxynil + bromoxynil (0?6 kg a.i. ha?1) and mecoprop improved control up to at least 90%, at most sites. Applications of mecoprop alone in April were most effective and frequently achieved more than 90% control. In May, when the G. aparine plants were very large, it was less successful. The reasons for the environmental effects on performance are discussed. Preliminary examination of the effect of soil temperature on mecoprop activity indicates that the reliability of control increases with increasing temperature (0–12°C). An average of 94% control was achieved when soil temperatures were greater than 6°C. La destruction de Galium aparine (Gaillet) dans les cereales d'hiver avec du mecoprop seul ou avec ioxynil plus bromoxynil 相似文献
7.
Chlortoluron, propyzamide, terbutryne and nitrofen were applied to the soil in pots with a rotary atomizer at 301 ha?1, with a conventional hydraulic nozzle at 400 1 ha?1 at several doses, or as discrete 2-μl drops applied with a microsyringe at 2-cm spacings. The test plants were Alopecurus myosuroides, Stellaria media, Chenopodium album, Avena fatua, perennial ryegrass and radish. Chlortoluron, propyzamide and terbutryne had the same activities following the rotary atomizer or conventional spray application but the rotary atomizer application of nitrofen was less effective against A. fatua than the conventional spray treatment. Chlortoluron, propyzamide and terbutryne showed appreciable activity applied as drops 2 cm apart at rates equivalent to 2 kg ai ha?1, on plants growing equidistant from the drops, but nitrofen showed no activity under these circumstances. The activity of chlortoluron was investigated at different soil moisture contents; it was more active when applied to moist soil than to dry soil which was not wetted for at least 10 h. Application method did not affect this response 相似文献
8.
Charles R. Riches Julia S. Knights Lilliana Chaves John C. Caseley Bernal E. Valverde 《Pest management science》1997,51(3):341-346
Pre-emergence activity of pendimethalin on propanil-resistant jungle rice (Echinochloa colona) was demonstrated in glasshouse trials. Both susceptible and resistant populations, collected from Costa Rica, were controlled by 1·25 kg ha-1, the usual application rate used in the field where Rottboellia cochinchinensis is also a problem. When applied post-emergence, propanil performance was improved by the addition of low doses of pendimethalin to the herbicide mixture. A propanil-resistant selection was controlled by 0·23 kg ha-1 pendi-methalin+0·54 kg ha-1 propanil at the one-to-two leaf stage, and 0·23 kg ha-1 pendimethalin+1·08 kg propanil at the three-to-four leaf stage compared to 1·08 kg and 2·16 kg ha-1 respectively when propanil was applied alone. This suggests that pendimethalin improves post-emergence control in the field compared to the standard propanil treatment and can provide residual pre-emergence control of late-germinating individuals, so reducing the propanil selection pressure. For effective jungle rice control, growers apply propanil (3·84 kg ha-1) at 10 and 20 days after planting (DAP) followed by one application of fenoxaprop-P-ethyl (0·045 kg ha-1) at 35 DAP. Field experiments, conducted in dry-seeded upland rice in southern Costa Rica, demonstrated that under high jungle-rice population pressure, one application of pendimethalin at 1·5 kg ha-1 provided an effective replacement for propanil, resulting in reduced weed-control costs. ©1997 SCI 相似文献
9.
MCPA, mecoprop, dichlorprop, dicamba, 2,3,6-TBA, bentazone, ioxynil/bromoxynil (a mixture), barban, difenzoquat and chlorfenprop-methyl were applied by spinning disc in controlled drop sizes from 150-350μm and at very low volume rates (5–45 1/ha), to the foliage of some dicotyledonous weed species or wild oats (Avena fatua L.). The same herbicides were also applied by means of conventional hydraulic nozzles at volume rates of about 200 1/ha. Most of these herbicides performed as well at very low volume rates as with the conventional application, the major exceptions being bentazone, ioxynil/bromoxynil (both of which have distinct contact effects) and dichlorprop. Comparisons between oil and water as the diluent at a very low volume rates suggest that there may be situations when oil is preferable and others when water is. 相似文献
10.
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
11.
B.J. WILSON 《Weed Research》1980,20(1):65-70
Mixed infestations of Alopecurus m yosuroides Huds. and broad-leaved weeds in winter cereals were controlled with a commercial formulation of ioxynil + bromoxynil + mecoprop. used in mixtures or as sequences with isoproturon or clofop-isobutyl. As well as controlling A. myosuroides the mixtures, applied in the autumn, gave good control of Veronica persica Poir., Galium aparine L. Lilhospermum arvense L. and Viola arvensis Murr. weeds which were resistant to isoproturon used alone. A. myosuroides had the major influence on crop yield in three experiments. High infestations of A. myosuroides reduced the broad-leaved weeds so that crop yields were only slightly improved when all the weeds were controlled compared with the control of A. myosuroides alone. In the remaining experiment. V. persica was very competitive with wheat; additional control of A. myosuroides improved yields considerably. Ioxynil + bromoxynil + mecoprop gave better final control of broad-leaved weeds when applied in the spring rather than the autumn but the sequence of a spring application following isoproturon or clofop-isobutyl in the autumn did not improve yields compared with the mixtures applied in the autumn. In all experiments, the highest yields were obtained from controlling both A. myosuroides and broad-leaved weeds in the autumn, provided that good control of A. myosuroides was obtained. 相似文献
12.
The possibility of increasing the activity of glyphosate, imazapyr, sulfonylurea herbicides and triclopyr against Rhododendron ponticum L. was investigated using container-grown plants. Glyphosate, imazapyr and triclopyr alone and metsulfuron-methyl with added surfactant were all phytotoxic, imazapyr and triclopyr being the most effective at the doses used. Thifensulfuron-methyl and tribenuron-methyl with ‘Mixture B’ were ineffective. The surfactants ‘Mixture B’ and ‘Silwet L77’ consistently increased the activity of imazapyr and metsulfuron-methyl. Mixtures of the herbicides did not lead to synergistic activity, and mixing imazapyr and triclopyr depressed the activity of each component. There was some enhancement of activity on R. ponticum when imazapyr and metsulfuron-methyl were applied sequentially, 48 h apart. Effets de mélanges d'herbicides et d'adjuvants au Rhododendron ponticum La possibilité d'accroître l'activité du glyphosate, de l'imazapyr, des sulfonylurées et du triclopyr contre Rhododendron ponticum a étéétudiée en utilisant des plantes cultivées en containers. Le glyphosate, l'imazapyr et le triclopyr seuls et le metsulfuron-methyl additionné d'un surfactant ont tous été phytotoxiques: l'imazapyr et le triclopyr étant les plus efficaces aux doses utilisées. Le thifensulfuron-méthyl et le tribenuron-methyl avec ‘Mixture B’ ont été inefficaces. Les surfactants ‘Mixture B’ et‘Silwet L 77’ ont considérablement augmenté l'activité de l'imazapyr et metsulfuron-methyl. Les mélanges des herbicides n'a pas abouti à une activité synergistique et les mélanges avec l'imazapyr et le triclopyr ont diminué l'activité de chaque composé. Il y a eu un certain renforcement de l'activité sur R. ponticum quand l'imazapyr et le métsulfuron-méthyl étaient appliqués de façon séquentielle, à 48 heures d'intervalle. Wirkung von Herbizidmischungen und Additiven auf Rhododendron ponticum An Container-Pflanzen von Rhododendron ponticum L. wurden versucht, die Wirksamkeit von Glyphosat, Imazapyr und Sulfonylharn-stoff-Herbiziden zu verstärken. Glyphosat, Imazapyr und Triclopyr allein und Metsulfuron-methyl nach Zugabe von Netzmitteln waren phytotoxisch, besonders Imazapyr und Triclopyr. Thifensulfuronmethyl und Tribenuron-methyl waren mit dem Netzmittel ‘Mixture B’ wirkungslos. Die Netzmittel ‘Mixture B’ und ‘Silwet L77’ erhöhten die Wirksamkeit von Imazapyr und Metsulfuron-methyl durchweg. Mischungen der Herbizide ließen keinen Synergismus erkennen, und die Mischung von Imazapyr mit Triclopyr verringerte die Wirksamkeit der Einzelkomponenten. Die Wirkung auf R. ponticum ließ sich erhöhen, wenn Imazapyr und Metsulfuron-methyl 48 h nacheinander angewandt wurden. 相似文献
13.
Studies have been carried out on the herbicidal action of asulam [methyl (4-aminophenylsulphonyl)carbamate] and sulphanilamide, alone or in association either with 4-aminobenzoic acid (4ABA) or 4, 6-diamino-1-(3, 4-dichlorophenyl)-1, 2-dihydro-2, 2-dimethyl-1,3,5-triazine (DCDT). The soaking of wheat seeds (Triticum estivum L.) for 12 h at 30°C in asulam and DCDT in a 10:1 ratio doubled the inhibition of root growth produced by soaking in asulam alone; the addition of 4ABA partially reversed the activity of asulam. Foliar applications of a mixture of asulam + DCDT (1.1 + 0.55 kg ha?1) markedly increased the activity of asulam in susceptible wheat, wild oat (Avena fatua L.), tolerant flax (Linum usitatissimum L.), and in Stellaria media L. The activity of asulam at 1.1 kg ha?1 was reversed by 4ABA at 2.2 kg ha?1 by about 50% in wheat and wild oat, 82% in flax and 100% in S. media. The results indicate that asulam and sulphanilamide act by similar mechanisms in apparently inhibiting the biosynthesis of folic acid. 相似文献
14.
A marked antagonism of A. fatua control was found when 2,4-D, dicamba, 2,4-D-dicamba-mecoprop or bromoxynil were added to benzoylprop ethyl, flamprop methyl or flamprop isopropyl. Because of the much poorer control of A. fatua by these mixtures obtaining broad spectrum weed control with them in one spray operation would not be possible. The A. fatua herbicides did not affect the activity of the added herbicides on Fagopyrum lataricum. In eight out of nine mixtures tested there was no significant antagonism in the field conditions when MCPA or bromoxynil-MCPA was added to the A. fatua herbicides. There were significant antagonistic effects, however, in six out of nine such mixtures in glasshouse experiments. This suggests that under farm use conditions benzoylprop ethyl, flamprop methyl or fiamprop isopropyl can be mixed with MCPA amine or ester or with bromoxynil-MCPA to obtain broad spectrum weed control from one spray operation, though slightly poorer A. fatua control may be expected with these mixtures. 相似文献
15.
The influence of broadleaf herbicides on imazamethabenz-methyl performance on wild oat (Avena fatua L.) plants grown outdoors in pots was examined. The foliar activity of imazamethabenz-methyl was reduced when applied in mixture with salt formulations of MCPA and mecoprop, salt and ester formulations of bromoxynil and bentazone. In contrast, chlorsulfuron had no influence and ester formulations of MCPA and mecoprop either had no effect or promoted imazamethabenz-methyl performance. A comparison of the activity of imazamethabenz-methyl in mixture with the ester formulation of MCPA and the corresponding formulation blank revealed that the antagonistic effect of MCPA active ingredient in the salt and ester formulations were similar. However, because of an enhancing effect of the formulation constituents in the ester formulation antagonism was masked in mixture with the latter. Similarly, addition of a mineral oil adjuvant only masked but did not eliminate the antagonistic interaction between the two herbicides. Volume rate did not affect imazamethabenz-methyl activity nor the antagonistic effect of the salt formulation of MCPA. The ester formulation of MCPA, however, promoted imazamethabenz-methyl performance significantly more at the low than at the high volume rate. Sequential application reduced antagonism of the salt formulation of MCPA on imazamethabenz-methyl. Selective placement of droplets revealed that antagonism occurred only if imazamethabenz-methyl and the salt formulation of MCPA were applied in the same droplet but not as separate droplets. Neither foliarnor root-applied MCPA reduced the performance of root-applied imazamethabenz-methyl. The results indicate that antagonism of MCPA was caused by a reduced uptake. The implications of the results of the present study in relation to the performance of tank mixtures of imazametha-benz-methyl and broadleaf herbicides under field conditions are discussed. Effet d'herbicides antidicotylédones sur l'efficacité de l'imazaméthabenz-méthyle contre la folle avoine (Avena fatua L.) L'effet d'herbicides antidicotylédones sur l'efficacité de l'imazaméthabenz-méthyle contre la folle avoine (A vena fatua L.) a étéétudié sur des plantes cultivées en pot à l'extérieur. L'activité foliaire de l'imazaméthabenz-méthyle était réduite quand il était appliqué en mélange avec des formulations sel de MCPA, et de mécoprop, et des formulations sel ou ester de bromoxynil et de bentazone. Par contre, le chlorsulfuron n'avait aucun effet, et les formulations ester ou sel de mécoprop et de MCPA, soit n'avaient aucun effet, soit augmentaient l'efficacité de l'imazaméthabenz-méthyle. Une comparaison de l'efficacité de l'imazaméthabenz-méthyle en mélange avec une formulation ester de MCPA et avec le blanc de formulation correspondant, a montré que l'effet antagoniste de la matiére active MCPA était similaire dans les formulations sel et ester. Cependant à cause de l'effet stimulateur de constituants de la formulation ester, l'antagonisme était masqué dans le mélange. De mßme, l'addition d'une huile minérale masquait mais ne supprimait pas l'antagonisme entre les deux herbicides. Le volume d'application n'affectait pas l'efficacité de l'imazaméthabenzméthyle non plus que l'effet antagoniste de la formulation sel du MCPA. L'augmentation d'efficacité de l'imazaméthabenz-méthyle par la formulation ester du MCPA était significativement plus élevée à bas qu'à haut volume. Une application séquentielle réduisait l'antagonisme de la formulation sel du MCPA sur l'imazaméthabenz-méthyle. Des applications sélectives de gouttelettes ont montré que l'antagonisme ne se produisait que si l'imazaméthabenz-méthyle et la formulation sel de MCPA étaient appliquées dans la même gouttelette mais non dans des gouttelettes séparées. Le MCPA, qu'il soit appliqué sur le feuillage ou par les racines, n'affectait pas l'efficacité de l'imazaméthabenz-méthyle appliqué par les racines. Les résultats indiquent que l'antagonisme était provoqué par une réduction de la pénétration. Les implications pratiques des résultats de cette étude sur l'efficacité des mélanges d'imazaméthabenz-méthyle et d'herbicides antidicotylédones au champ sont discutées. Einfluß von Herbiziden gegen Dikotyle auf die Wirkung von Imazamethabenz-methyl auf Flug-Hafer (Avena fatua L.) Der Einfluß von Herbiziden gegen Dikotyle auf die Wirkung von Imazamethabenz-methyl auf Flug-Hafer (A vena fatua L.) wurde im Freiland in Topfversuchen untersucht. Die Wirkung von Imazamethabenz-methyl über das Blatt war herabgesetzt, wenn es in Mischung mit Salzformulierungen von MCPA und Mecoprop sowie Salzund Esterformulierungen von Bromoxynil und Bentazon ausgebracht wurde. Chlorsulfuron dagegen hatte keinen Einfluß, und Esterformulierungen von MCPA und Mecoprop beeinflußten die Wirkung von Imazamethabenz-methyl weder positiv noch negativ. Ein Vergleich der Wirksamkeit des Imazamethabenz-methyls in der Mischung mit der Esterformulierung von MCPA und der entsprechenden Leerformulierung zeigte, daß der antagonistische Effekt des Wirkstoffs MCPA in der Salz-und der Esterformulierung ähnlich war; die wirkungsfördernden Bestandteile der Esterformulierung maskierten jedoch den Antagonismus. In ähnlicher Weise wurde der Antagonismus zwischen zwie Herbiziden durch den Zusatz von Mineralöl nur überdeckt, aber nicht aufgehoben. Die Aufwandmenge blieb sowohl auf die Wirksamkeit des Imazamethabenz-methyls als auch auf den Antagonismus der MCPA-Salz formulierung ohne Einfluß. Aber bei der niedrigen Aufwandmenge förderte die Esterformulierung von MCPA die Wirkung von Imazamethabenz-methyl signifikant mehr als bei der hohen. Aufeinander folgende Anwendung mäßigte den Antagonismus der MCPA-Salz-formulierung auf Imazamethabenz-methyl. Der Antagonismus trat nur auf, wenn Imazamethabenz-methyl mit MCPA-Salzformulierung zusammen, nicht aber in getrennten Tröpfchen nebeneinander appliziert wurde. Weder übers Blatt noch über die Wurzeln appliziertes MCPA minderte die Wirkung von wurzel-appliziertem Imazamethabenz-methyl. Die Ergebnisse zeigen, daß der Antagonismus von MCPA durch eine reduzierte Aufnahme zustande kam. Die Untersuchungsergebnisse werden hinsichtlich der Wirksamkeit von Tank-mischungen von Imazamethabenz-methyl mit Herbiziden gegen Dikotyle unter Freiland-bedingungen diskutiert. 相似文献
16.
Control of Avena fatua with tralkoxydim was significantly reduced in glasshouse experiments when the herbicide was tank-mixed with either 2,4-D amine or bentazone. Antagonism increased with increasing rates of these broadleaf herbicides in the tank-mixture and it could, in turn, be decreased by increasing rates of tralkoxydim. When herbicide solutions were applied to single leaves with a micropipette applicator, bentazone was antagonistic only when mixed in the same droplet with tralkoxydim and not when the two herbicides were applied adjacently in separate droplets. In contrast, both separate and combined applications of 2,4-D amine and tralkoxydim were antagonistic. There was no antagonism when mixtures with either 2,4-D amine or bentazone were applied between the leaf sheath and culm. Antagonism could be circumvented by sequential applications of the herbicides. When tral-oxydim was applied first, there was no loss of A. fatua control if bentazone application was delayed 0.5 h or if 2,4-D amine was delayed 24 h. Results suggest that bentazone affects only cuticular penetration of tralkoxydim, whereas 2,4-D amine also influences subsequent translocation. 相似文献
17.
In glasshouse experiments, additions of 10–100 g 1?1 ammonium sulphate enhanced the phytotoxicity to broadleaved weeds and cereals of several water-soluble herbicides applied post-emergence in 75–300 1 ha?1 with hydraulic nozzles. Studies with dichlorprop potassium salt and chickweed Stellaria media (L.) Vill. examined interactions between ammonium sulphate and environmental, application and formulation factors. Simulated rainfall immediately after spraying greatly reduced dichlorprop activity, whether or not ammonium sulphate was present. However, when there was an interval of 2–24 h between spraying and rainfall, the additive increased phytotoxicity. Surfactants tended to reduce dichlorprop phytotoxicity to Stellaria media, both in the presence and absence of ammonium sulphate. Certain other inorganic salts including sodium sulphate also enhanced phytotoxicity. Applications by rotary atomizer in very low spray volume (15 1 ha?1, 250–280 μm drops) were less effective than conventional 150 1 ha?1 applications. When very low volume application was used, addition of ammonium sulphate or nitrate tended to reduce activity further. In the field, ammonium sulphate significantly increased the effects against weeds of a commercial dichlorprop potassium salt formulation applied conventionally in 200 1 ha?1 spray volume. Neutralized phosphoric acid had a similar effect but a mixture of this additive and ammonium sulphate reduced phytotoxicity. Both additives slightly increased dichlorprop injury to barley. 相似文献
18.
甲磺隆的应用技术及对后茬作物的安全性研究 总被引：3，自引：0，他引：3
在冬小麦 1～ 2叶期施用甲磺隆 1.8～ 2.5 g/hm2 ,可有效防除北京地区麦田常见阔叶杂草 ,优于当前常用除草剂苯磺隆 15g/hm2 春季施用的除草效果 ,安全性与春季施用苯磺隆 15g/hm2 相当。实验室降解结果表明 ,当甲磺隆初始浓度为 6.25μg/kg以下时 ,经过215d后 ,对后茬玉米安全。研究表明 ,向日葵是甲磺隆理想的生物测定试材 ,对甲磺隆的最低检出浓度达到 0.125μg/kg,其根长抑制率与除草剂浓度有高度的相关性 ,最佳的剂量 -反应模型为 y=a+b lnx 相似文献
19.
D. J. Turner 《Pest management science》1972,3(3):323-331
The possibilities are demonstrated of increasing the activity of foliar applied growth regulator herbicides by mixing them with chemicals which injure the cuticle or epidermis. S, S, S-Tributyl phosphorotrithioate (“DEF”) increases the effects of picloram, 2,4,5-T and mecoprop salts on four woody species, privet (Ligustrum ovalifolium Hassk.), poplar (× Populus gelrica Ait.), bluegum (Eucalyptus globulus Labill.) and guava (Psidium guajava L.). Mixtures with esters of the herbicides are not synergistic and often antagonistic. DEF, tributyl phosphorotrithioite, a number of alkyl and aryl phosphates and phosphites and potassium ethyl xanthate enhance the phytotoxicity of picloram solution on dwarf bean (Phaseolus vulgaris L.). Mixtures of picloram with tributyl phosphorotrithioite, tributyl phosphate, mixed acid butyl phosphates, trimethyl phosphate and mixed isomers of tritolyl phosphate are synergistic when applied to guava foliage. Tributyl phosphate and mixed acid butyl phosphates interact similarly with picloram on privet and tributyl phosphate increases the effects of foliar applied mecoprop salt on guava. The mode of action of the additives is not fully understood but there is evidence that DEF facilitates the entry of water soluble growth regulator herbicides into leaves and has little effect on the rate at which the herbicides move through the plant. Tributyl phosphate and mixed acid butyl phosphates are suggested for practical use in herbicide formulations to control woody plants, as they are relatively cheap and non-toxic. 相似文献
20.
E. S. MOHAMED A. H. NOURAI G. E. MOHAMED M. I. MOHAMED M. C. SAXENA 《Weed Research》1997,37(4):211-218
Weeds are a major constraint to increasing production of lentil (Lens culinaris Medik.) in Sudan, Field studies were conducted to determine the yield loss due to weeds, to identify the critical period of weed interference, to evaluate the activity of different herbicide mixtures in controlting weeds and their selectivity for lentil, and to evaluate different methods of weed control for developing an integrated weed management practice. At Rubatab. unrestricted weed growth accounted for up to 84% loss in yield. The critical period of weed control was between 2 and 4 weeks after sowing. However, a weeding regime experiment at Dongola, a cooler location with a longer growing season, indicated that the critical period was between 4 and 6 weeks after sowing. suggesting that the critical period might vary with the environmental conditions. The herbicides imazethapyr (0.05 kg a.i. ha-1), terbutryn (1.0 kg a.i. ha-1) and prometryn (1.0 kg a.i. ha-1), each in a tank mixture with pendimethalin (1.2 kg a.i. ha-1), were tolerated by lentil, controlled weeds effectively and significantly increased yields at Wad Hamid. Their efficacy in controlling weeds at Rubatab was low, however, because of the presence of Tephrosia apollinea (Del.) DC. and Melilotus indica (L.) All., which tolerated these herbicides. Efficacy was also reduced in heavier soils. One supplementary hand-weeding at 4 weeks after sowing enhanced the performance of these herbicides under such conditions. A tank mixture of oxyfluorfen (0.24 kg a.i. ha-1) with either terbutryn (1.0 kg a.i. ha-1) or prometryn (1.0 kg a.i. ha-1) also provided good weed control and increased yield of lentil at Wad Hamid. Application of a higher dose (1.5 kg a.i. ha-1) of terbutryn and prometryn caused phytotoxicity. Irrigation before seed-bed preparation reduced grass and broad-leaved weeds by 58% and 40% respectively, and gave a 30% increase in grain yield over no irrigation. Pre-emergence application of oxyfluorfen (0.24 kg a.i. ha-1) and a supplementary hand-weeding at 4 weeks after sowing gave excellent control of weeds and increased lentil yield by 57% over the weedy control. Thus, use of presowing irrigation, pre-emergence herbicide and one hand-weeding form an effective integrated package for controiling weeds in northern Sudan. 相似文献