几种除草剂对马蹄金草坪阔叶杂草的防治试验

用除草剂防治马蹄金草坪中的阔叶杂草．对马蹄金草坪的生产、养护意义重大。通过田间试验．除草剂高特克在常规用量时．对马蹄金草坪安全．用药后阔叶杂草的死亡率达86．78％。     

Promising herbicides for weed control in chickpea

Abstract

Chickpea suffers severe competition due to Chenopodium album L. infestation. Two to three hoeings are generally given to check C. album but increasing labour costs and scarcity of farm labour make the manual weeding difficult. Usage of herbicides appears to be a logical solution. Pre‐emergence applications of pendimethalin or ametryn alone at 1.5 kg ai ha^?1 or one handweeding at 35–40 days after seeding following either 1 kg ai ha^?1 of pendimethalin, ametryn or fluchloralin or metribuzin at 0.3 kg ai ha^?1 applied pre‐emergence gave effective control of C. album and seed yields similar to clean‐weeded chickpeas. There was an 84% reduction in seed yield of chickpea without weeding.     

Herbicide-resistant crops and weed resistance to herbicides

The adoption of genetically modified (GM) crops has increased dramatically during the last 3 years, and currently over 52 million hectares of GM crops are planted world-wide. Approximately 41 million hectares of GM crops planted are herbicide-resistant crops, which includes an estimated 33.3 million hectares of herbicide-resistant soybean. Herbicide-resistant maize, canola, cotton and soybean accounted for 77% of the GM crop hectares in 2001. However, sugarbeet, wheat, and as many as 14 other crops have transgenic herbicide-resistant cultivars that may be commercially available in the near future. There are many risks associated with the production of GM and herbicide-resistant crops, including problems with grain contamination, segregation and introgression of herbicide-resistant traits, marketplace acceptance and an increased reliance on herbicides for weed control. The latter issue is represented in the occurrence of weed population shifts, the evolution of herbicide-resistant weed populations and herbicide-resistant crops becoming volunteer weeds. Another issue is the ecological impact that simple weed management programs based on herbicide-resistant crops have on weed communities. Asiatic dayflower (Commelina cumminus L) common lambsquarters (Chenopodium album L) and wild buckwheat (Polygonum convolvulus L) are reported to be increasing in prominence in some agroecosystems due to the simple and significant selection pressure brought to bear by herbicide-resistant crops and the concomitant use of the herbicide. Finally, evolution of herbicide-resistant weed populations attributable to the herbicide-resistant crop/herbicide program has been observed. Examples of herbicide-resistant weeds include populations of horseweed (Conyza canadensis (L) Cronq) resistant to N-(phosphonomethyl)glycine (glyphosate). An important question is whether or not these problems represent significant economic issues for future agriculture.     

Influence of application volume on the efficacy of clodinafop-propargyl and fenoxaprop-P-ethyl on oats

The influence of application volume on the efficacy of clodinafop‐propargyl and fenoxaprop‐P‐ethyl on cultivated oats (Avena sativa) was studied in the glasshouse. Both herbicides were more efficacious when applied in 75 L ha^?1 than in 300 L ha^?1, with 11002 and 11006 nozzles respectively. However, when the same two volume rates were created by varying the speed of a 11003 nozzle, clodinafop‐propargyl efficacy was not affected by application volume, whereas fenoxaprop‐P‐ethyl remained more efficacious at 75 L ha^?1. This suggests that in the first experiment, fenoxaprop‐P‐ethyl efficacy was affected by changes in both spray quality and concentration, whereas only the former influenced clodinafop‐propargyl efficacy. The hypothesis that the fenoxaprop‐P‐ethyl formulation was more influenced by concentration than clodinafop‐propargyl was supported by dynamic surface tension studies and measures of active ingredient retention by oat plants. Within the practically relevant concentration range considered, surface activity of clodinafop‐propargyl remained low, with little influence on herbicide retention. In contrast, depending on the concentration, surface activity of fenoxaprop‐P‐ethyl was below or above levels that were critical for its retention. Although these differences may not be as apparent in the field as in the glasshouse, our study certainly indicates that both clodinafop‐propargyl and fenoxaprop‐P‐ethyl are herbicides favoured by low application volumes.     

不同茎叶处理除草剂对麦田禾草的防除效果

近几年来 ,麦田中的硬草、早熟禾等恶性杂草呈逐年上升趋势 ,已成为江苏省姜堰市麦田杂草的优势种 ,而生产上推广应用的除草剂对硬草、早熟禾等杂草的防除效果不理想。为筛选出高效药剂 ,2 0 0 1年我们对 3%世玛、5 5 %普草克、6 9%骠马防除麦田恶性杂草进行了大田对比示范。1　示范处理共设 6个处理 :(1) 3%世玛油悬剂 30ml 6 6 7m2 ;(2 ) 3%世玛油悬剂 35ml 6 6 7m2 ;(3) 5 5 %普草克油悬剂12 5ml 6 6 7m2 ;(4 ) 5 5 %普草克油悬剂 15 0ml 6 6 7m2 ;(5 )6 9%骠马水乳剂 10 0ml 6 6 7m2 ;(6 )清水对照。以上药剂均由安万特公司提供 ,不设…     

亚麻田化学除草剂药效试验报告

用56％2甲4氯钠盐50g／667m^2 5％精喹禾灵乳油50ml/667m^2、17．5％油草双克乳油100ml/667m^2、50％敌草隆可湿性粉剂50g／667m^2 56％2甲4氯钠盐50g／667m^2、50％扑草净可湿性粉剂50g/667m^2 56％2甲4氯钠盐50g／667m^2，对亚麻生长安全，除草效果好。     

不同除草剂对空心莲子草的控制作用评价

采用盆栽试验,测定了氯氟吡氧乙酸、草甘膦和五氟磺草胺对不同生育期空心莲子草的控制作用,以株防效、鲜重防效和再生抑制率为指标,评价了不同除草剂对空心莲子草的控制效果。结果表明,药后7 d,氯氟吡氧乙酸、草甘膦和五氟磺草胺对不同生育期空心莲子草的株防效,均低于15%;药后15 d,氯氟吡氧乙酸和草甘膦对不同生育期的空心莲子草的株防效、鲜重防效均达100%,但五氟磺草胺对不同生育期的空心莲子草的株防效较差。药后30 d,氯氟吡氧乙酸和五氟磺草胺对不同生育期空心莲子草的再生抑制作用较强,抑制效果达74%以上;草甘膦对生长后期的再生抑制作用达81.3%。空心莲子草苗期对不同除草剂的反应最为敏感。氯氟吡氧乙酸可以作为水生环境和旱生环境下防除空心莲子草的重点药剂,草甘膦可用于旱地空心莲子草的防除,五氟磺草胺可作为水生环境条件下防除空心莲子草的主要药剂之一。     

杂草对激素类除草剂抗药性研究进展

农田杂草严重影响作物的产量和品质,对除草剂的过度依赖和长期使用,使杂草对除草剂的抗性问题日益突出。目前已有262种杂草(152种双子叶和110种单子叶)的512个生物型对23类中的167个除草剂产生抗性。激素类除草剂作为除草剂的重要成员,为禾谷类作物田的杂草防除提供了保障,然而在使用了几十年后,44种杂草对此类除草剂产生了抗药性。本文对激素类除草剂的分类应用、除草机理、抗性现状、抗性机理等进行了综述,以期为激素类除草剂的应用和抗激素类除草剂杂草的防除提供参考。     

不同茎叶处理剂防除油菜田单子叶杂草试验

近年来,由于油菜田草相的不断改变,油菜田使用茎叶处理剂后局部地区除草效果较差,为了摸清原因,探索新的防除途径,我们于2002年冬季分别在江苏省太仓市金浪、双凤、城厢等镇进行药剂试验,现将试验情况小结如下。     

Impact of post-emergence herbicides on weed community diversity within conservation-tillage systems

The influence of herbicides on weed community dynamics is an issue of agroecological concern. A field study was initiated in 1986 with zero-, minimum-, and conventional-tillage systems. In 1989 and 1990, the fourth and fifth years of study, weed community diversity and relative composition were assessed prior to and following the application of post-emergence non-residual herbicides. Weed communities were assessed at the level of tillage system to balance the effect of different crop sequences and crop-herbicide combinations within each comparison. In general, herbicides did not reduce community diversity when compared by Shannon's H’and dominance-diversity curves. An increase in species richness and evenness, as assessed by Shannon's E and Margalef's D_MG occurred in some cases. Differences in relative community composition among tillage systems were apparent before the application of herbicides, but disappeared following herbicide application. The use of herbicides in this study reduced weed densities, maintained weed diversity, and inhibited community changes that were due to changing tillage systems.     

不同除草剂控制机插水稻田阔叶杂草的效果

13%2甲4氯钠AS 4 500 g/hm2防除水稻田阔叶杂草效果很好,40%2甲.异丙隆WP 1 800 g/hm2防效次之,48%灭草松AS 1 500 mL/hm2处理防效最差。以上除草剂对水稻生长安全。     

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.     

不同除草剂对稻田杂草群落演替的影响

为了明确除草剂对稻田杂草群落演替的影响,2001～2004年,连续4年施用7种稻田除草剂控制移栽稻田杂草,每年调查稻田杂草的种类、密度和鲜重,分析稻田杂草种群的变化.结果表明：连续使用同一除草剂对稻田杂草群落演替影响显著,靶标杂草的优势度值与药剂使用年限存在显著的线性或非线性关系：Y=a＋bx或Y=ax^2＋bx＋c;非靶标杂草优势度值与药剂使用年限呈极显著正相关线性关系.不同药剂处理的杂草群落有一定的差异,连续使用二元复配除草剂,杂草群落的均匀度和多样性指数分别为0.40～0.43和1.57～1.84,明显低于单剂处理和对照区,田间主要杂草是陌上菜、水苋、千金子和水莎草,其杂草的鲜重显著低于其它处理.     

综观以化学除草剂为主体的稻田杂草防治技术体系

根据中国稻田杂草发生、分布特点和秧田、直播田、移栽田、抛栽稻田等不同水稻栽培环节或栽培措施，综述了以相应的化学除草剂种类、使用剂量、使用方法以及田间管理措施形成的化除技术体系，同时也介绍了一些稻田除草剂新品种。最后还就稻田杂草防治过程中面临的挑战进行了讨论。     

Evaluation of herbicides for selective weed control in grafted watermelons

Grafted watermelon is a combination of two plants, aCucurbita rootstock and a watermelon scion. Therefore, weed control for this crop faces a unique problem: the safety of the selected herbicide has to be tested for both plants that make up the grafted plant. In the current study, we evaluated the usage safety of selected herbicides forCucurbita rootstocks as well as for non-grafted and grafted watermelons, and the control ofAmaranthus retroflexus by the same herbicides. In addition, the residual effect of the herbicides was tested for seeded and transplanted melons representing the next crop following cultivation of the grafted watermelons. The herbicides ethalfluralin, pendimethalin, ethalfluralin, sulfentrazone, oxyfluorfen, chlorsulfuron and clomazone were chosen for their potential to controlA. retroflexus. Pendimethalin and trifluralin were less effective than the other herbicides in controllingA. retroflexus; sulfentrazone, chlorsulfuron and clomazone were not safe for use on the tested cucurbits and thus cannot be recommended for weed control in grafted watermelons. Therefore, by eliminating the herbicides that are toxic to cucurbits and those that are ineffective forA. retroflexus control, it was concluded that the herbicides ethalfluralin and oxyfluorfen can be considered effective and safe for weed control in grafted watermelons. It was shown that trifluralin and oxyfluorfen have the potential to be applied effectively through the drip irrigation system. http://www.phytoparasitica.org posting Jan. 10, 2008.     

胡萝卜田苗后杂草化学防除药剂筛选

为探究安全、高效的胡萝卜田苗后杂草化学防除技术,采用盆钵法研究了13种苗后茎叶处理除草剂对胡萝卜的室内安全性,并对筛选得到的苗后除草剂进行了初步的田间药效及安全性试验。结果表明：供试13种除草剂中扑草净对胡萝卜的安全性较好,在225 g（a.i.）/hm²剂量下,胡萝卜苗的鲜重为53.61 g,与对照无显著差异,未出现药害反应;在450、750 g（a.i.）/hm²剂量下分别出现了1级和2级的低级别药害反应;而噁草酮、氰草津、嘧啶肟草醚、双草醚、辛酰溴苯腈、乙氧氟草醚、乙羧氟草醚、咪唑乙烟酸、灭草松、噻吩磺隆、双氟磺草胺和氯吡嘧磺隆在推荐剂量下,对胡萝卜鲜重抑制率为19.30%~100.00%,出现了3~5级的药害反应。扑草净对胡萝卜田杂草有较好的防效,在剂量为450~600 g（a.i.）/hm²时对胡萝卜田杂草总体的株防效和鲜重防效均达到80.56%以上,且对胡萝卜安全,无药害反应。胡萝卜田苗后杂草化学防除建议使用450~600 g（a.i.）/hm²扑草净进行茎叶喷雾处理,可达到对禾本科和阔叶杂草的有效防除,且对胡萝卜安全。     

Susceptibility of a broad-leaved weed, Acanthospermum hispidum, to the grass herbicide fluazifop-butyl

Broad-leaved plants are generally resistant to aryloxyphenoxypropionate (AOPP) and cyclohexanedione (CHD) herbicides. In laboratory experiments, however, we confirmed that Acanthospermum hispidum , a Compositae weed, was susceptible to one of the AOPP herbicides, fluazifop-butyl, but tolerant to other AOPP herbicides (quizalofop-ethyl and fenoxaprop-ethyl) and a CHD herbicide (sethoxydim). The symptoms induced by fluazifop-butyl in A. hispidum (wilting and necrosis) were distinctly different from those induced in oat (chlorosis). The period required to cause seedling death of A. hispidum (48–72 h) was shorter than that of oat ( ca 15 days). The ( R )-enantiomer of fluazifop-butyl was more active on this weed. In oat, lipid biosynthesis and acetyl-CoA carboxylase (ACCase) activity were inhibited, and electrolyte leakage from the shoots was increased by fluazifop-butyl and sethoxydim. In the case of A. hispidum , the membrane permeability increased and the lipid biosynthesis was inhibited only by fluazifop-butyl. These results indicate that A. hispidum is particularly sensitive to fluazifop-butyl, and its mechanism of action in the plant may be different from its mechanism of action in oat.     

几种药剂对沿江地区麦田阔叶杂草的防效

江苏省仪征市地处长江下游沿江地区,麦田草害较重,尤其是近几年来,田间草相以猪殃殃、荠菜、繁缕这3种阔叶杂草为主,为了找出有效防除以上杂草的药剂,我们选择了几种药剂进行试验,确定了最佳使用药剂,现将试验结果报道如下。