Influence of pre-emergence herbicides on root development of Agrostis stolonifera sod*

Agrostis stolonifera Huds cv.‘Penncross’ and cv.‘Cohansey’(bentgrass) were maintained as a golf-course putting green. Five herbicides were evaluated at normal (1 x) and three times normal (3 x) rates for Digitaria sanguinalis (L.) Scop (Crabgrass) control and influence on root development of sod. The herbicides were applied once (April), twice (April and August) and three times (April, June and August) annually. After application of 3 × rates, benfluralin (N-butyl-N-ethyl-2,6, dinitro-4-triflouromethylaniline) and chlorthal-dimethyl (2,3,5,6-tetrachloroterephthalic acid dimethyl ester) caused injury on both A. stolonifera cultivars. Shoot injury remained with repeated benfluralin treatments; however, injury was no longer apparent after the first application of chlorthal-dimethyl. Terbucarb (2,6-di-t-butyl-p-tolyl N-methylcarbamate) completely killed both cultivars during the second year of the study. Bensulide (N-[2-(0,0-di-isopropyldithiophosphoryl)ethyl]benzene sulphonamide) and siduron (N-(2-methylcyclohexyl)-N-phenylurea) did not influence shoot growth of either A. stolonifera cultivars. Chlorthaldimethyl, bensulide and siduron allowed excelent sod rooting in both cultivars. The 3 × rate of the three herbicides did affect rooting of ‘Cohansey’ cultivar during the second year of the study, as did the 1 × rate of benfluralin. The benfluralin injury did not persist from one treatment time to the next, even at 3 × rates. Terbucarb restricted root growth for the entire year. Bensulide and siduron provided acceptable D. sanguinalis control and acceptable A. stolonifera tolerance under golf-course green management and re-establishment with turf.     

Influence of broad-leaved weed herbicides on the activity of fenoxaprop-P-ethyl

The activity of fenoxaprop-P-ethyl applied alone or in tank-mixture with different formulations of mecoprop or sulfonylurea herbicides was compared in a series of pot experiments using Avena fatua L. (wild oat) as a test plant. A logistic model was fitted to the results and dose–response curves of fenoxaprop-P-ethyl applied alone and in mixture with the broad-leaved weed herbicides were estimated using non-linear regressions. Tank-mixtures of fenoxaprop-P-ethyl and mecoprop or metsulfuron-methyl were antagonistic. In general, the activity of fenoxaprop-P-ethyl decreased with increasing doses of the broad-leaved herbicides. In mixture with 1200 g a.i. ha^?1 mecoprop, doses of fenoxaprop-P-ethyl had to be increased by 60% to 130% (dependent on formulation) to obtain the same effect as when fenoxaprop-P-ethyl was applied alone. Both the active and the inactive isomers of mecoprop were involved in the antagonism, and the ester formulation of mecoprop-P was less antagonistic than the amine formulation. In mixture with the recommended dose of 8 g a.i. ha^?1 of metsulfuron-methyl, doses of fenoxaprop-P-ethyl had to be increased by 20% to 110% to obtain the same effect as with fenoxaprop-P-ethyl applied alone. Fenoxaprop-P-ethyl did not lose activity when applied in mixture with recommended doses of chlorsulfuron, tribenuron and amidosulfuron. Antagonism of the sulfonylurea herbicides seemed to be related to the susceptibility of A.?fatua to these herbicides.     

微生物除草剂研究发展及开发展望

介绍了国内、外微生物除草剂的研究发展概况及成功商品化开发、利用实例;评述了该类除草剂资源丰富、以新作用位点防除杂草、对非靶标植物影响不大、对环境负效应小、安全性高,符合可持续农业发展要求等优点;展望了由于现代生物手段的不断成熟,发酵技术、分子遗传学和基因工程的最新发展,带给微生物除草剂的开发优势和发展前景。     

9种除草剂对花生白绢病菌的影响

在实验室条件下测定了氟乐灵、乙草胺、异丙甲草胺、异恶草酮、乳氟禾草灵、乙氧氟草醚、三氟羧草醚、恶草酮、二甲戊乐灵等9种除草剂对花生白绢病菌Sclerotium rolfsi Sacc.的影响.结果表明:9种除草剂对花生白绢病病菌的毒力有较大差异,三氟羧草醚和乙氧氟草醚的毒力较高,IC50分别为7.88mg·L-1和18.91mg·L-1;9种除草剂对菌丝干重均有抑制作用,且随剂量的升高而升高,乙氧氟草醚和三氟羧草醚抑制作用最明显,在100mg·L-1和50mg·L-1时抑制率均达90%以上;除乙草胺和异丙甲草胺部分剂量外,其他除草剂对菌核数量均有不同程度的抑制作用,三氟羧草醚作用最为明显,在供试剂量下抑制率均达96%以上;除乙草胺、氟乐灵在供试剂量下对菌核单重有抑制作用外,其他除草剂在多数剂量下对菌核单重均有刺激作用,三氟羧草醚在50mg·L-1时,是对照菌核单重的8.34倍;而各种除草剂在供试剂量下,对菌核萌发均没有影响.     

Influence of herbicides on photosynthetic activity and transpiration rate of intact plants

The effect of various herbicides on photosynthesis, respiration and transpiration of intact plants has been studied in a routine assembly. Simultaneous measurements were made under different experimental conditions in four small plant chambers, in which the shoots of various plant species can be accommodated. The herbicide is applied during measurement, so that the effect can be related to the photosynthetic activity of the same plants before treatment. The selectivity of various herbicides was studied by determining the capacity of a plant species to inactivate a herbicide absorbed by the roots. These and other differential effects of various herbicides on photosynthetic activity of different plant species coincide with the selective properties in the field. Such differences are also observed after leaf sprayings. The duration of the experiments is kept short. Bean plants were studied under various experimental conditions of air humidity, light intensity and temperature resulting in different transpiration rates. The decrease in photosynthetic activity owing to the presence of a herbicide in the nutrient solution at a standard concentration was more rapid at the higher transpiration rates. The total transpiration during treatment up to 50% inhibition of photosynthesis was constant under the various experimental conditions. Specific inhibitors of the photosynthetic process had a more pronounced effect on the photosynthetic activity than on transpiration rate. Some other herbicides affect transpiration as well as photosynthesis.     

Influence of some 1,3,5-triazine herbicides on peroxidase activity in corn seedlings

The effect of some 1,3,5-triazine herbicides, on the rate of oxidative decarboxylation of tryptophan by peroxidase from corn seedlings, varied with the concentration. Atrazine was stimulatory in vivo at 10-⁶M but not at 10⁸ M or lower, whereas terbutryne was inhibitory at 10-⁶M but not at 10-⁸M or below. Prometryne inhibited enzyme activity at 10-⁶M and stimulated it at 10-¹⁰M and at 10¹²M, while simazine caused stimulation at 10-⁶M and inhibition at 10^?10M and 10^?12M. Atraton reduced enzyme activity at 10^?6M and 10^?8M but had no effect at 10^?10M and 10^?12M. When peroxidase activity was assayed in acetone-dried powders from seeds, harvested from fields that had received typical atrazine applications, the quantities of tryptophan consumed were significantly less than the quantity determined in the control powder. From the results obtained, by incorporating dealkylated and 2-hydroxy metabolites of atrazine at 10^?6M into the culture solutions, it seems possible that the inhibition observed may have been due to the presence of 4-amino-6-ethylamino-1, 3, 5-triazin-2-ol and/or 4, 6-diamino-1, 3, 5-triazin-2-ol residues in seeds from treated plots, even if, in previously reported experiments, analyses had not detected their presence.     

Influence of the herbicides hexazinone and chlorsulfuron on the metabolism of isolated soybean leaf cells

The effects of the herbicides hexazinone [3-cyclohexyl-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4(1H,3H)-dione] and chlorsulfuron (2-chloro-N-[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)aminocarbonyl]benzenesulfonamide) on the metabolism of enzymatically isolated leaf cells from soybean [Glycine max (L.) Merr., cv. ‘Essex’] were examined. Photosynthesis, protein, ribonucleic acid (RNA), and lipid syntheses were assayed by the incorporation of specific radioactive substrates into the isolated soybean leaf cells. These specific substrates were NaH¹⁴CO₃, [¹⁴C]leucine, [¹⁴C]uracil, and [¹⁴C]acetate, respectively. Time-course and concentration studies included incubation periods of 30, 60, and 120 min and concentrations of 0.1, 1, 10, and 100 μM of both herbicides. Photosynthesis was the most sensitive and first metabolic process inhibited by hexazinone. RNA and lipid syntheses were also inhibited significantly by hexazinone whereas the effect of this herbicide on protein synthesis was less. The most sensitive and first metabolic process inhibited by chlorsulfuron was lipid synthesis. Photosynthesis, RNA, and protein syntheses were affected significantly only by the highest concentration of this herbicide and longest exposure. Although these two herbicides may exert their herbicidal action by affecting other plant metabolic processes not examined in this study, hexazinone appears to be a strong photosynthetic inhibitor, while the herbicidal action of chlorsulfuron appeared to be related to its effects on lipid synthesis.     

几种除草剂对恶性杂草野艾蒿的防除效果及对胡麻生长发育的影响

采用田间试验的方法,测定了几种除草剂单剂和混用配方对胡麻田恶性杂草野艾蒿的防除效果及对胡麻生长发育的影响。结果显示,75%二氯吡啶酸SG+56%2甲4氯钠盐SP、75%二氯吡啶酸SG+90%莠去津WG混配、75%二氯吡啶酸SG单剂对野艾蒿的株防效、地上部鲜重防效、地下部鲜重防效分别达到93.24%～97.46%、94.69%～96.77%和90.13%～96.40%,对靶标杂草野艾蒿防除效果明显且对胡麻无药害,胡麻产量较空白对照分别增加36.59%、4.14%和20.86%。48%灭草松AS虽对野艾蒿的综合防效较低,但其对胡麻无药害且胡麻蒴果数、千粒重较大,胡麻产量较空白对照增长61.27%。90%2甲·草甘膦SP、82%草甘膦异丙胺盐AS、20%氯氟吡氧乙酸EC、70.5%2甲·唑草酮WG、20%敌草快AS 5种除草剂对胡麻安全性低,不宜应用于胡麻田野艾蒿的防治。结合各除草剂处理后胡麻的药害、经济性状、生物产量、籽粒产量以及对野艾蒿的防除效果进行综合分析,胡麻田野艾蒿防除除草剂选择适宜度依次为:75%二氯吡啶酸SG+56%2甲4氯钠盐SP混配75%二氯吡啶酸SG48%灭草松AS75%二氯吡啶酸SG+90%莠去津WG混配。本文为胡麻田恶性杂草野艾蒿的化学防除提供了理论依据。     

手性除草剂研究进展

以几大类已经商品化或具有较好市场前景的手性除草剂为对象,综述了各除草剂的除草活性、对非靶标生物的毒性及其在环境迁移中的对映异构体选择性现象及机理的研究成果。由于对映异构体间的生物学性质迥异,因此,手性除草剂对映异构体的活性、作用机理、代谢转化及其在生物体内的转移等都具有手性选择性差异。同时,手性除草剂对植物的选择性作用还会因作用对象及环境因素的改变而改变,其在环境中的选择性降解情况也十分复杂,不仅与该除草剂自身的理化性质有关,还与其所处的环境因素有关,诸如土壤类型、植物种类、微生物群落结构、温度、pH值等均会改变手性除草剂对映异构体的环境归趋。     

Long-term effects of herbicides on the photosynthetic apparatus I. Influence of diuron, triazines and pyridazinones

Long-term effects of herbicides on the photosynthetic membrane system were investigated. For this purpose the unicellular alga Bumilleriopsis filiformis was grown in liquid culture in the presence of sublethal concentrations of diuron, atrazine, metribuzin, and some substituted pyridazinones. This allowed reproducible growth conditions, exact dosing of herbicides, and also the preparation of functionally active cell-free photosynthetic systems. The electron transport system of cells grown in the presence of ureas and triazine derivatives is not impaired at all, wherea scultivation with pyridazinones damages their photosynthetic redox system. In addition, a strong bleaching effect is observed, whereas the first group of herbicides enhance chlorophyll formation.     

Effect of some herbicides on freshwater algae

The activity of 12 herbicides was tested against various freshwater algae found in Britain. Three of the most troublesome species, Cladophora glomerata L., Rhizoclonium hieroglyphicum Katz., and Vaucheria dichotoma Ag. were all susceptible to methylthio-1,3,5-triazines. Terbutryne and cyanatryn were the most active and both killed C. glomerata and R. hieroglyphicum at 0.05 mg/litre. The concentration of terbutryne had to be increased to 0.1 mg/litre to control V. dichotoma. Asulam and WSCP (2.0 mg/litre), metflurazone and HZ5914 (1.0 mg/litre), copper sulphate (1.0 mg copper ion/litre) and cutrine (2.0 mg copper ion/litre) had no visible effect on the algae. Diquat (1.0 mg cation/litre) did, however, control C. glomerata and R. hieroglyphicum although, in natural conditions, the algae quickly recovered after treatment. Success with diquat (2.0 mg/litre) against V. dichotoma in laboratory experiments was not achieved in a field experiment.     

三种复配增效剂对除草剂的增效作用

为研究3种复配增效剂对灭草松、草铵膦、高效氟吡甲禾灵的增效作用及其增效机制,并筛选出表现较好的增效剂,分别测定了以顺丁烯二酸二异辛酯磺酸钠(渗透剂T)、异构醇醚和油酸甲酯为主要成分的3种复配增效剂以及分别添加了这3种复配增效剂的除草剂的静态表面张力(static surface tension,SST)、动态表面张力(...     

几种除草剂在燕麦田的应用效果

通过9种除草剂1,0个处理,对3个燕麦品种进行3次重复试验,初步筛选出异丙甲草胺＋苯达松茎叶喷雾对燕麦等禾本科杂草具有理想的防除效果。     

Chemistry of sulfonylurea herbicides

The discovery of the sulfonylurea class of herbicides is one of the most dramatic breakthroughs in herbicide research in several decades. Sulfonylureas possess unprecedented levels of herbicidal activity–as low as 1 g ha^?1–very low mammalian toxicity, and very desirable environmental properties. This review will discuss the structure-activity relationships of sulfonylureas, their physical and chemical properties, and their methods of synthesis.     

酰胺类除草剂的安全剂

本文主要介绍了酰胺类除草剂的应用概况、安全剂开发情况及其作用机理，并对安全剂前景等作了简要展望。     

磺酰脲类除草剂对加拿大一枝黄花的防除效果

3月中旬至4月中旬加拿大一枝黄花幼苗高15cm以下，用75％甲嘧磺隆印～80g／667m^2或40％葫芦净150～200g／667m^2，防除非耕地加拿大一枝黄花的效果达90％以上，并能杀死根茎，可以达到一次用药根除的目的。     

复合型助剂对不同除草剂的增效作用

本文利用田间试验及仪器分析的方法系统研究了不同类型助剂对除草剂的增效作用.结果表明,供试的几种助剂对草甘膦都具有明显的增效作用,其增效顺序为:复合型助剂＞甲酯化植物油＞有机硅助剂＞非离子表面活性剂＞葡萄糖助剂＞氮盐类助剂.复合型助剂能够明显降低草甘膦药液的表面张力及干燥时间,降低幅度可达30％以上,并且明显增加药液的扩...     

浅谈除草剂药害及其补救措施

作物受害是除草剂应用中存在的一个重要问题,因为任何作物都不能完全抵抗除草剂的药害,只能忍耐一定剂量的除草剂,也就是说除草剂对作物与杂草的选择性不是绝对的,超越其选择范围对作物就会产生药害。在农业生产过程中应了解除草剂的药害表现、药害原因,这对做到正确使用除草剂是非常重要的。     

Effect of trickle irrigation on soil-applied herbicides*

The effect of trickle irrigation on the activity, leaching and distribution in the soil of herbicides, was studied in a model specially constructed for simulating trickle irrigation in the field, and also under field conditions. The pattern of movement of a soil-applied herbicide in the soil under trickle irrigation paralleled, to some extent, that of the trickle water itself, but total herbicide movement was less than that of the water. Both water and herbicide distribution in the soil formed the shape of a hemisphere or cone under the trickle nozzle, the exact shape of which was determined by the soil characteristics (a narrow cone in a light soil and a wide cone in a heavy soil); cone size was determined by the amount of trickle water. Bioassays with susceptible test plants showed that effective weed control could be expected with either simazine or GS-14259 (2-t-butylamino-4-ethylamino-6-methoxy-s-triazine =‘Caragard') only in the areas wetted by the trickle nozzle. The results showed that the pattern of distribution in the soil of simazine and GS-14259 was similar, but there were quantitative differences in their final spread.