新型玉米除草剂的防效与评价研究

为了筛选既对玉米生长无明显影响又能有效防除玉米地杂草的新型除草剂,2005-2006年对宝玉、玉邦和金玉黄龙3种除草剂进行了药剂试验,结果表明,玉邦除草剂用于苗前和苗后玉米4~8叶期、杂草2~4叶期防除杂草均有很好的防效,3种除草剂对杂草防效的排序为:玉邦>宝玉>金玉黄龙。     

肇东苜蓿除草剂安全性试验研究

【研究目的】探讨研究除草剂对肇东苜蓿耐药性的影响,可筛选出对苜蓿无药害的除草剂品种和使用方法。【方法】通过小区试验,在苜蓿分枝期对各除草剂处理苗情和草情进行观察记载。【结果】对苜蓿无药害的药剂处理有75%阔叶散播后苗前喷雾、5%金普施特苗后2~4叶期喷雾、4%金豆苗后2~4叶期喷雾、10%利收苗后2~4叶期喷雾。【结论】苜蓿无药害的除草剂品种和使用方法推荐5%金普施特播后苗前和苗后2~4叶期喷雾。     

Environmental impacts from herbicide tolerant canola production in Western Canada

The commercial production of herbicide tolerant (HT) canola began in Western Canada in 1997. With more than a decade of use, the actual farm-level environmental impact of HT canola can be evaluated. This article reports on a spring 2007 survey of nearly 600 canola farmers in the three prairie provinces of Western Canada. Producers were asked about their crop production experiences for 2005 and 2006 and expected crop planting for 2007. A reduction in the total number of chemical applications over the 3-year period was reported, resulting in a decrease of herbicide active ingredient being applied to farmland in Western Canada of nearly 1.3 million kg annually. Fewer tillage passes over the survey period were reported, improving moisture conservation, decreasing soil erosion and contributing to carbon sequestration in annual cropland. An estimated 1 million tonnes of carbon is either sequestered or no longer released under land management facilitated by HT canola production, as compared to 1995. The value of this carbon off-set is estimated to be C$5 million. Comparisons with similar studies and against non-adoption of HT canola can guide future decisions about HT canola adoption.     

Management of cruciferous cover crops by mowing for soil and water conservation in southern Spain

In recent years, the use of cover crops in Mediterranean olive orchards has increased due to serious soil erosion problems and surface water contamination by herbicides. In these areas, the annual precipitation regime is strongly seasonal, with dry summers that require killing the cover crop before it competes with the trees for water. Cruciferous species are being introduced as cover crops in southern Spain, and their management by mowing could reduce the use of herbicides. However, the use of mowing as a management system requires an understanding of the phenology of these species to identify the most suitable mowing date to derive the greatest possible soil water content. The aims of this study were the following: (1) to assess the susceptibility of cruciferous species to mowing, their regrowth ability and the persistence of their residues on the soil surface after mowing, and (2) to identify the best mowing date for the cover crops in relation to the soil moisture content in the environmental conditions of southern Spain. For these purposes, the emergence, ground cover, biomass and regrowth after two mowing dates of common mustard (Sinapis alba L. subsp. mairei), rocket (Eruca vesicaria), radish (Raphanus sativus) and Ethiopian mustard (Brassica carinata) were evaluated in field trials during 2001/2002. In addition, during 2002/2003 and 2003/2004, the moisture content of soil sowed with common mustard and rocket cover crops was assessed at different mowing dates and compared with a bare soil control. Common mustard was the most favourable species for management by mowing due to its lack of regrowth after mowing. Early mowing (March 10th) reduced soil moisture due to the regrowth of the cover crop, fast decomposition of cover residues and weed proliferation. Late mowing (April 24th) led to little or no regrowth of the cover crops, large biomass and high persistence of cover residues, which provided effective soil ground cover, avoided the emergence of spring-summer weeds and helped retain soil moisture, reaching a similar water content to bare soil. These results suggest that cruciferous cover crops killed by mowing in late April can be used to replace no-tillage bare soil management systems to reduce the use of herbicides and preserve soil and water quality.     

奇善宝对世玛除草剂在小麦上的药害的恢复效应研究

在冬前麦田化学除草过程中,除草剂药害经常发生,以世玛等除草剂产生的药害较多,研究其缓解技术十分必要。针对世玛除草剂药害麦田,通过叶面喷施海洋寡糖生物制剂奇善宝,研究其对受害小麦恢复效应;受除草剂药害小麦叶面喷施奇善宝后7天,小麦植株开始有别于对照,25天后处理株高、绿叶数量、次生根显著高于对照,处理产量增加了549.30 kg/hm2,增产9.7%。同时喷施奇善宝在一定程度上改善籽粒品质,稳定时间增加15.7%,吸水率较对照降低1.4%,硬度、沉降值、出粉率和拉伸参数差异不显著;奇善宝可显著缓解除草剂对小麦的危害程度,有显著的增产效应,并在一定程度上改善籽粒品质。     

Agricultural practice changes with cultivating genetically modified herbicide-tolerant oilseed rape

To facilitate weed suppression, oilseed rape or canola (Brassica napus) has been genetically modified (GM) over the last two decades to incorporate herbicide tolerance (HT). The introduction of oilseed rape in commercial agriculture raises concerns about potential adverse agronomic and environmental effects linked to both the genetic modification and altered agricultural practice. How will this new crop modify the existing cropping practice? What are the potential agro-environmental implications of its introduction? This paper analyses and schematises recorded and conceivable agricultural practice changes with GMHT oilseed rape introduction and its likely agro-environmental effects. It develops a conceptual systematics of influencing factors, subsequent practice changes and likely agro-environmental effects. The results can be used to design the mandatory monitoring of adverse GM crop effects.     

Degradability of atrazine, cyanazine, and dicamba in methanogenic enrichment culture microcosms using sediment from the Pearl River of Southern China

Degradation of three herbicides, atrazine, cyanazine and dicamba, was assessed in laboratory microcosms incubated under simulated methanogenic conditions using sediment from Pearl River of Southern China as an inoculum. Atrazine was much more resistant to degradation than cyanazine and dicamba over 300 days of incubation. Biodegradation of cyanazine and dicamba was further substantiated by establishment of enrichment transfer cultures in which the degradation of the respective herbicide was accelerated by the active microorganisms. Degradation of cyanazine initially involved the removal of chlorine and the two side chains, while that of dicamba was O-demethylation reaction forming 3,6-dichlorosalicyclic acid. Results suggest that biodegradation of xenobiotics can be established through enrichment culture transfer technique, and further mechanism of degradation and microorganisms involved can be elucidated.     

11种除草剂对秋播豌豆生长发育的影响及防效研究

化学除草剂已成为农田控制杂草的重要技术措施,但目前还没有针对豌豆田杂草的高效、安全除草剂。为此,本文以陕西省关中地区主栽品种‘西豌2号’为试验材料,采用6种苗前除草剂（48%氟乐灵乳油、50%乙草胺乳油、33%二甲戊灵乳油、96%精异丙甲草胺乳油、50%敌草胺水分散粒剂、40%扑草净可湿性粉剂）和5种苗后除草剂（15%精吡氟禾草灵乳油、10%精喹禾灵乳油、12.5%烯禾啶乳油、10.8%高效氟吡甲禾灵乳油、12%烯草酮乳油）处理,设清水喷施（CK1）和人工除草（CK2）为对照,调查秋豌豆田杂草种类,研究不同除草剂的防除效果,探讨各除草剂对秋豌豆生育进程、形态特征、经济效益等相关指标的影响。结果表明：1）研究区秋豌豆田杂草共7科13种,以阔叶类杂草为主,其中阔叶杂草9种。除草剂对杂草株数和鲜重均有不同程度的防效作用,苗前除草剂以33%二甲戊灵综合防效最佳,苗后除草剂以12%烯草酮综合防效最佳。2）自越冬期至开花期,各除草剂均对秋豌豆株高、叶绿素相对含量产生显著影响,但从始荚期开始,影响不再显著。不同种类的除草剂对秋豌豆根、茎、叶器官各时期干物质的积累量均有不同程度的抑制作用,各处理的秋豌豆茎、叶器官干物质的移动率及转运率均高于人工除草,叶器官干物质的移动率及转运率均高于茎器官。3）除草剂对百粒重、荚长等产量构成因素影响不显著,除10.8%高效氟吡甲禾灵导致产量略微下降之外,其他除草剂均表现出一定的增产作用,其中33%二甲戊灵、12%烯草酮可使秋豌豆增产25%以上。所有除草剂处理的净收入均有所增加,以33%二甲戊灵、12%烯草酮处理的净收入为同时期除草剂中最高。由此可见,除草剂的使用有助于种植者经济效益的提高,结合各除草剂的防除效果、安全性、经济效益,苗前除草剂33%二甲戊灵和苗后除草剂12%烯草酮在秋豌豆田的综合效应分别为同时期除草剂中最佳。本试验条件下,针对秋豌豆田,苗前除草剂推荐使用33%二甲戊灵,苗后除草剂推荐使用12%烯草酮。     

两种农药悬乳剂的配制及应用

采用湿磨法，选用适量的两种表面活性剂、增稠剂、防冻剂等分别制成４８％乙草胺·莠去津悬乳剂和４８％丁草胺·莠去津悬乳剂，可解决用同类药剂配制可湿性粉剂含量低的问题，而且其物理和应用性能优于可湿性粉剂和悬浮剂。田间试验表明，两种悬乳剂对夏玉米地主要杂草──马唐的防除效果优于莠去津单用，残留量符合标准。     

Evaluation and management of acetyl-CoA carboxylase inhibitor resistant littleseed canarygrass (Phalaris minor) in Pakistan

A field survey was conducted for the sampling of Acetyl-CoA carboxylase (ACCase) inhibitor resistance littleseed canarygrass, a major weed of wheat, from Punjab, Pakistan in 2014 for confirmation of resistance. The surveyed regions encompassed four different cropping systems including rice–wheat, maize–wheat, cotton–wheat and mixed cropping. Dose–response assay was conducted for confirmation of resistance. Efficacy of herbicide mixtures including clodinafop–propargyl, metribuzin, pinoxaden and sulfosulfuron at a range of doses was investigated to manage littleseed canarygrass. Results revealed that all populations were resistant to fenoxaprop except PM-BWL-2. The higher level resistance (6.5) was found in populations collected from rice–wheat cropping system. The tested herbicide mixtures at 75% and 100% of the recommended dose of each mixture component provided the effective control of resistant littleseed canarygrass. Mixtures at 50% provided more than 80% control and reduced growth and seed production potential of surviving plants. The confirmation of ACCase inhibitor resistance as the first case of herbicide resistance in Pakistan, leads us to discourage use of ACCase inhibitor herbicides alone. However, herbicide mixtures at 75% and 100% of the recommended dose are suggested to manage this weed for sustainable wheat production in the surveyed cropping systems.