皖南稻田除草剂药害发生现状及其预防对策

皖南稻区水稻除草剂药害呈现发生频率高、大型事故增多、影响层面广泛的新特点。造成药害的主要除草剂包括磺酰脲类的胺苯磺隆、甲磺隆、氯磺隆、甲嘧磺隆,灭生性除草剂草甘膦、百草枯,酰胺类的乙草胺、丙草胺、异丙甲草胺,以及2甲4氯、二氯喹啉酸等。药害原因可分为使用者原因、生产者原因、经营推广者原因、环境因素影响等多种。介绍了缓解药害的经验措施。提出从源头上加强除草剂登记与质量管理．在销售和使用环节加强对有关人员的专业知识培训．严格试验示范推广程序,谨慎使用除草剂等预防对策。     

甲草胺·乙草胺·莠去津悬浮剂中混有2甲4氯造成棉花药害的技术鉴定

除草剂使用不当所造成的危害已日益成为我国农业可持续发展的一大障碍，而药害的技术鉴定及治理又非常复杂。文章根据棉花受害症状、反应速度、周边杂草受害症状及农药企业的基本生产情况等，初步确定可能造成药害的除草剂种类。利用气质联用仪将供试药害的样品与一些标样在同一条件下的总离子流色谱图和质谱图进行比较，确认甲草胺·乙草胺·莠去津悬浮剂中含有造成棉花药害的2甲4氯，并测定2甲4氯的含量为6．0％。     

甲草胺·乙草胺·莠去津悬浮剂中混有2甲4氯造成棉花药害的技术鉴定

除草剂使用不当所造成的危害已日益成为我国农业可持续发展的一大障碍,而药害的技术鉴定及治理又非常复杂.文章根据棉花受害症状、反应速度、周边杂草受害症状及农药企业的基本生产情况等,初步确定可能造成药害的除草剂种类.利用气质联用仪将供试药害的样品与一些标样在同一条件下的总离子流色谱图和质谱图进行比较,确认甲草胺·乙草胺·莠去津悬浮剂中含有造成棉花药害的2甲4氯,并测定2甲4氯的含量为6.0%.     

苯磺隆、2甲4氯防除谷田杂草的药害与增产效果

苯磺隆、2甲4氯两种除草剂防除谷田杂草时,施药前期对谷子表现药害症状,后期消失,对产量的影响较小。     

中华人民共和国农业部公告第671号停止批准新增含甲磺隆等除草剂产品的登记

为进一步解决甲磺隆等磺酰脲类长残效除草剂对后茬作物产生药害事故的问题,保障农业生产安全．保护广大农民利益,根据《农药管理条例》的有关规定,结合我国实际,我部决定对含甲磺隆、氯磺隆和胺苯磺隆等除草剂产品实行以下管理措施。     

襄阳市一起小麦除草剂药害鉴定案例分析

由"真骠"牌"苯磺隆"假农药害案件,对襄阳市部分地区小麦田除草剂药害情况进行诊断鉴定及比较试验。结果表明,含助剂的"真骠"牌苯磺隆除草剂会导致小麦叶片发黄、植株瘦弱、分蘖较少甚至心叶卷曲发黄致死,且擅自加大施药浓度和低温施药对小麦造成的损失更大。通过对试验结果的分析,提出了加强除草剂市场监管、慎重选择和正确使用除草剂等预防除草剂药害的建议。     

各地管理情况

安徽查处甲磺隆、绿磺隆、胺苯磺隆及其复配制剂据安徽省农药检定所在全省范围内对甲磺隆、绿磺隆、胺苯磺隆及其复配制剂使用情况进行调查摸底表明 ,全省因前茬使用上述除草剂造成夏播作物药害的面积每年都在百万亩以上 ,严重影响了农民增收和农业可持续发展。安徽省决定 ,认真组织一次针对甲磺隆、绿磺隆、胺苯磺隆及其复配制剂的专项检查活动 ,发现一处 ,查处一处 ,决不姑息 ,以禁用农药论处 ;对已经造成夏播作物药害的 ,应协调有关部门做好善后处理和受损农户的安定工作 ;各地农业行政主管部门要联合工商、公安、技术监督部门加大查处力…     

4种除草剂防除保护性耕作麦田早熟禾效果及其对作物的安全性

通过田间试验,比较4种除草剂药后不同时期对保护性耕作麦田早熟禾的防效及其增产效果,进而比较7．5％啶磺草胺WG、3．6％甲基二磺隆·甲基碘磺隆钠盐WG、15％炔草酸WP、6．9％精唑禾草灵EW 4种除草剂防除早熟禾效果和对小麦的安全性。采用田间药效试验方法,对麦田早熟禾采用喷雾处理,进行4种除草剂防除麦田早熟禾效果及其对作物的安全性试验。7．5％啶磺草胺WG 187．50 g/hm2和3．6％甲基二磺隆·甲基碘磺隆钠盐WG 450．00 g/hm2对早熟禾鲜质量防效分别为83．58％、84．87％。3．6％甲基二磺隆·甲基碘磺隆钠盐WG对春小麦通麦1号品种有一定的药害,药害程度：甲基二磺隆·甲基碘磺隆钠盐＞啶磺草胺。6．9％精唑禾草灵EW、15％炔草酸WP对早熟禾达未到防治要求。187．50 g/hm27．5％啶磺草胺WG,安全性好、防效高、持续期长,可进一步示范推广使用。     

甲磺隆、氯磺隆等除草剂的登记应用现状及防止药害的几项管理措施

甲磺隆、氯磺隆等除草剂由于除草活性高,用药量小,常常被人们称之为“超高效除草剂”。同时,它们在土壤中残效期较长,分解慢,而在旱田中分解更慢,残效期可达6个月左右,因此使用不当,极易对农作物引起药害。1甲磺隆、氯磺隆等除草剂的登记应用情况目前取得甲磺隆原药登记的农药企业共有11家,登记氯磺隆原药和胺苯磺隆原药的企业各有6家。甲磺隆制剂共有36个产品,主要为甲磺隆单剂以及与苄嘧磺隆或与乙草胺等的混剂;氯磺隆制剂共有18个产品,主要为氯磺隆单剂以及与苯磺隆、甲磺隆或与异丙隆等除草剂的混剂;胺苯磺隆制剂有16个产品,主要为胺苯…     

胺苯磺隆“后效应”对移栽水稻影响的观察

胺苯磺隆是一种广谱、高效、低毒的油菜田除草剂。由于其杀草谱广、效果好、价格低廉,近年在油菜田中的应用面积逐年增加。但由于农民在使用过程中难以准确掌握用量,加上连年应用,引起土壤中胺苯磺隆残留物的累积,当累积达到一定浓度时,其"后效应"显著,即不仅对秧苗造成药害,还会使大苗移栽水稻因药害造成减产,甚至绝收。桐庐县岭源乡 1997年冬在油菜除草上开始应用,至今已有 3 a。 2000年 6月在本乡中村畈发现较大面积前茬油菜田大苗移栽单季稻发生药害,受害面积 6.7 hm2,其中枯死面积 0.4 hm2。为指导今后生产,我们对前茬油菜…     

种植模式对棉田土壤处理除草剂除草效果的影响

露地直播棉田苗期除草,可以选用50%乙草胺EC5、0%扑草净WP和33%二甲戊乐灵EC。地膜覆盖棉田9,6%精异丙甲草胺EC4、8%氟乐灵EC5、0%萘丙酰草胺WP5、0%扑草净WP和48%仲丁灵EC对棉田杂草的防效较理想,药后45 d的株防效仍能达到83%以上。金都尔等7种除草剂在露地直播棉田中使用对棉苗生长无影响,而在地膜覆盖棉田使用乙草胺和二甲戊乐灵应慎重,浓度过高易对棉花幼苗产生药害。     

湖南省棉田杂草调查

对湖南省棉花主产区棉田杂草的种类、发生规律及化学除草情况进行了调查。结果发现, 湖南省棉田常见杂草包括12科, 28种, 其中禾本科杂草占25.00%, 阔叶杂草占67.86%, 莎草科占7.14%; 一年生杂草占78.57%, 多年生杂草占21.43%。相对多度10%以上的杂草有7种, 其中马唐、牛筋草、千金子、铁苋菜、小飞蓬5种杂草为湖南省棉田杂草的优势种, 相对多度分别为37.79%、33.64%、29.15%、26.23%、23.83%。杂草发生呈现3个高峰期, 分别为5月下旬, 6月中下旬, 7月下旬至8月初, 杂草防除主要采用苗前土壤处理和苗后茎叶处理相结合的化学防除方法。     

棉叶螨危害对棉花生理和产量的影响

棉叶螨危害致使棉花生理和代谢发生紊乱是造成棉花减产的内在原因。1984—1985年,作者采用人工接螨和控制螨量的方法,任其自然繁殖28天,使各处理株间出现螨量和被害指数梯度,然后测定各处理株主要生理参数及其产量。结果表明,当全株每叶初接螨量在5头以上、螨群最高繁殖量高于35头时,处理株比对照株组织水势增高13.11—34.31％;叶绿素含量减少39.60—62.50％;光合强度减弱23.47—89.29％;过氧化氢酶活性降低22.79—48.04％;呼吸强度变化差异不显著。棉叶中可溶性糖、全氮、全磷损失显著,营养恶化。单株籽棉重降低35.18—45.10％,平均铃重降低24.34—35.53％。据此,确定棉叶螨防治标准为全株平均每叶螨量20头。     

Chemical cotton stalk destruction for maintenance of host-free periods for the control of overwintering boll weevil in tropical and subtropical climates

In the Lower Rio Grande Valley (LRGV) of Texas, cotton regrows and produces fruit from undestroyed stalks throughout the winter, and in spring weevils from such locations become a serious threat. The success of the boll weevil eradication program, which was reintroduced in the LRGV in 2005, will be dependent on thorough stalk destruction following harvest. However, adverse weather conditions and conservation tillage often impede immediate and complete stalk destruction using typical tool implements, and alternative stalk control methods are needed. This study provides an examination of the efficacy for cotton stalk destruction of different herbicides (thifensulfuron-methyl + tribenuron-methyl, dicamba-diolamine, 2,4-D-dimethylammonium, flumioxazin, 2,4-DB-dimethylammonium and carfentrazone-ethyl) and their rates, spray volumes and application timings on shredded or standing cotton stalks after stripper or picker harvest. None of the tested herbicides, except 2,4-D-dimethylammonium, stopped post-harvest cotton regrowth and fruiting. 2,4-D-dimethylammonium sprayed once (0 or 7 days) after cotton was harvested at 1 lb AE acre(-1) (1.12 kg ha(-1)), in a spray volume of 10 gal water acre(-1) (93.5 L ha(-1)) with 5 mL L(-1) surfactant, was highly effective in stalk destruction (72-90%). The best results were achieved when the herbicide was applied immediately after the cotton was shredded, followed by standing stripper-harvested and standing picker-harvested cotton. 2,4-D-dimethylammonium applied twice, 0 and 14 (or 21) days after cotton harvest, was 100% effective in killing stalks, regardless of whether they were shredded or standing, or whether harvest was by stripper or picker. These findings showed that 2,4-D-dimethylammonium cotton stalk destruction eliminated food and reproductive opportunities for managing overwintering boll weevils [Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae)].     

氟乐灵等5种除草剂对棉花枯萎病发生及棉花抗病性的影响

在温室盆栽条件下,研究了5种常用除草剂(氟乐灵、除草醚、丁草胺、扑草净和草甘膦)对棉花枯萎病发生及棉花抗病性的影响。结果表明:施用除草剂同时接种病原,氟乐灵播前土壤处理减轻了浙肖棉1号(感病)和中棉12号(抗病)棉花苗期枯萎病的发生;而其他4种除草剂则不同程度地促进了苗期枯萎病的发生。播前土壤药剂处理,出苗1周后接种病原,氟乐灵和除草醚提高了棉花对枯萎病的抗性,扑草净降低了棉花的扰病性,而草甘膦则不影响棉花的抗病性。     

氟乐灵等5种除草剂对棉花枯萎病发生及棉花抗病性的影响

在温室盆栽条件下,研究了5种常用除草剂(氟乐灵、除草醚、丁草胺、扑草净和草甘膦)对棉花枯萎病发生及棉花抗病性的影响。结果表明:施用除草剂同时接种病原,氟乐灵播前土壤处理减轻了浙肖棉1号(感病)和中棉12号(抗病)棉花苗期枯萎病的发生;而其他4种除草剂则不同程度地促进了苗期枯萎病的发生。播前土壤药剂处理,出苗1周后接种病原,氟乐灵和除草醚提高了棉花对枯萎病的抗性,扑草净降低了棉花的扰病性,而草甘膦则不影响棉花的抗病性。     

Chemical Control of Weeds in Cotton in the Sudan Gezira

Abstract

Early work on chemical weed control in the fallow towards the end of the Second World War is reviewed briefly. Attempts to use contact residual herbicides as pre-emergence applications in the early 1950s are also described.

Pre-sowing applications of residual herbicides were found more phytotoxic to cotton than pre-emergence applications. The closer the time of pre-sowing application to cotton sowing, the more effective was suppression of weeds competing with cotton.

Mechanical cultivations and particularly disc ploughing and rotovation to a depth of more than 15 cm were found more effective in the control of Cynodon dactylon than pre-sowing herbicide applications.

Fluometuron, noruron and prometryne were found very effective as pre-emergence herbicides. Optimum rates of application were found to be only 25-50% of rates recommended for the USA and other countries. Resistant weeds included Cyperus rotundus, Cynodon dactylon, and Rhyncosia memnonia.

A large-scale trial with fluometuron, covering 125 feddans at Wad el Nairn showed that yields obtained were equal to those with normal weeding. Costs of herbicide treatments were also comparable to costs of hand-weeding in a year of exceptionally low hand-weeding costs.     

Critical periods of weed competition in cotton in Greece

Four experiments were conducted in central Greece during 1997 and 1998 to determine the late-season presence of weeds in cotton (Gossypium hirsutum L.) and the critical times for removing weeds. Experiments were conducted in natural, heavily infested cropland. The presence of weeds for more than 3 weeks after crop emergence caused significant reductions in crop growth and lint yields. However, weeds that emerged 11 weeks or more after crop emergence did not adversely impact yields. Total weed biomass increased with increasing time prior to weed removal. A weed-free period of 11 weeks after crop emergence was needed to prevent significant reductions in cotton height, biomass, number of squares, and yield. These results indicated that postemergence herbicides or other control measures should be initiated within 2 weeks after crop emergence to avoid significant yield reduction. For greater efficiency, soil-applied herbicides in cotton should provide effective weed control for at least 11 weeks. Curvilinear regression equations were derived to describe the relationship between critical periods of weed presence and cotton growth and fruit development.     

不同生育期转基因抗草甘膦抗虫棉花对草甘膦的耐受性

为明确转基因抗草甘膦抗虫棉田草甘膦的使用适期,于棉花子叶期、3~4片真叶期和花铃期喷施不同浓度的草甘膦,比较药害发生情况、棉花产量和纤维品质。棉花子叶期、3~4片真叶期和花铃期喷施1 640~9 840 g/hm²(有效成分,下同)草甘膦后,施药初期棉花均表现出一定的药害症状,药后4~8 d药害株率和药害指数达最大值,药后12 d药害症状逐渐减轻或消失。棉花子叶期和3~4片真叶期喷施草甘膦,对棉花产量无显著影响,但棉花花铃期喷施2 460~9 840 g/hm²草甘膦后,棉花产量显著降低,降幅达35.0%~63.3%。3个时期喷施草甘膦均不影响棉花的纤维品质。研究表明,转基因抗草甘膦抗虫棉田草甘膦的使用适期为棉花苗期。