小麦田除草剂应用技术

通过对麦田杂草生长状况以及影响麦田除草剂使用因素的剖析,针对性地提出了解决对策和途径,包括除草剂类型的选择,最佳防治期的选择,根据常见麦田的杂草选择何种化学除草药剂,除草药剂量的使用,提高除草剂喷施质量的要求等,并结合近几年我国小麦田的优势杂草种类,主要应用的除草剂分析了目前国内麦田杂草的抗药性现状及防治对策。     

春玉米化学除草剂药害的发生原因及其预防和缓解技术措施

在河北省隆化县,玉米田化学除草剂药害发生程度逐渐加重、面积逐年加大,严重影响了玉米生产。分析了造成玉米田化学除草剂药害的主要原因,并提出了合理适期选用化学除草剂、注意天气情况、提高喷药技术,运用农业技术并辅助喷洒植物生长调节剂等措施,可以预防和缓解药害的发生。     

春谷除草剂筛选及防效研究

选用12种除草剂对春谷田间杂草防效进行了田间试验研究。结果表明,播后苗前进行土壤处理,12种除草剂中有4种致谷苗死亡;其余8种对谷子幼苗均有一定的抑制作用,但拔节前可恢复正常;施药后15,30,45 d调查,莠去津和2,4-D丁酯2种除草剂的防效较好,对双子叶杂草的株防效、鲜质量抑制率、综合株防效、综合鲜质量抑制率均超过80%,莠去津优于2,4-D丁酯。     

黑龙江省长残留除草剂应用及残留药害情况调查

目前生产上使用的长残留除草剂主要有氯嘧磺隆、咪草烟、氟磺胺草醚、异噁草松和莠去津。涉及药害的作物有大豆、水稻、玉米、亚麻、马铃薯、白瓜、甜菜及一些经济作物。为改善农业生态环境和促进农业生产,对黑龙江省长残留除草剂的使用及产生残留药害的情况进行了调查。结果表明:2012年黑龙江省长残留除草剂使用商品量7 659.2t,有效量2 473.8t,可用面积305.72万hm2次。2012年全省使用有效量比2011年增加18.16%。2012年全省长残留除草剂造成的残留药害面积达65.81万hm2次,药害发生面积最多的是黑河地区,达21.09万hm2次,其次是佳木斯地区18.88万hm2次,哈尔滨地区11.17万hm2次。建议限制和减少长残留除草剂的生产和使用,推广应用降低除草剂残留的新技术。     

池杉苗圃地化学除草试验

池杉苗圃地的化学除草试验结果表明：克芜踪以剂量３０００ｍｌ／ｈｍ＾２的除草率最高，可达８０％，但除草不彻底。剂量为４５００－７５００ｍｌ／ｈｍ＾２的草甘膦，除草率可高达８５．５％。二甲四氯与克芜踪混施，最佳配方是３０００ｍｌ／ｈｍ＾２克芜踪＋１５００ｍｌ／ｈｍ＾２二甲四氯，除草率高的可达９０．８８％除草效果与成本考虎，３种除草剂中以草甘膦除草率高，杂草死亡彻底，成本较低。     

Soil and weed management for enhancing arbuscular mycorrhiza colonization of wheat

Tillage and weed control are critical components of cropping systems that need to be combined such that crops benefit from reduced competition. However, weeds may also contribute to the biological diversity within the agro‐environment. This greenhouse study investigated whether common weeds of arable cropping systems were suitable host plants for arbuscular mycorrhizal fungi (AMF), allowing the development of extraradical mycelium (ERM) that can contribute to the early colonization of a following wheat crop, especially in the absence of soil disturbance. Weeds were allowed to grow for up to 2 months before being controlled by soil disturbance or herbicide application (glyphosate or paraquat). Pregerminated wheat seeds were then planted. Chemical control of the weeds prior to sowing enhanced the early arbuscular mycorrhiza (AM) colonization rate of wheat roots, whereas mechanical disturbance was less acceptable as a method of weed control for rapid AM colonization. The type of herbicide (contact or systemic) had no impact on colonization of the wheat crop. Enhanced AM colonization promoted early P acquisition and growth of the crop. Appropriate management of weeds emerging between two consecutive cropping seasons coupled with no‐till soil management could ensure a quick and efficient AM colonization of the following wheat plants.     

Predictive models of weed population dynamics

Many of the challenges faced by weed ecologists can be met only by the capability to predict the responses of weed populations to changes in their environment or management. In spite of this, a review of papers published in Weed Research suggests that weed ecologists are remarkably reluctant to produce detailed, quantitative predictions. This may result from uncertainty in the accuracy of predictions and indeed, a variety of reasons have been put forward to suggest that the potential utility of weed models may be limited in this regard. In this study, we review the applications to which weed models have been put. Focusing on predictive population modelling, we highlight several limitations that can lead to failures of this approach and we discuss the likely prospects for weed population modelling. We make three points regarding the future of weed modelling. First, owing to prohibitive data requirements, the development of highly mechanistic models that attempt to make detailed predictions of weed population numbers is unlikely to be very successful. Second, data collection for developing weed models needs to be rethought. Weed models are most commonly compromised by a lack of spatial and temporal replication, preventing modellers from measuring parameter variability and error effectively and limiting assessments of model uncertainty. Finally, the utility of models needs to be better appreciated; models are key tools in making long range predictions of how management will affect weed populations, but, we estimate, they are used in only a small fraction of studies. Without the further development of models for weed population dynamics, our ability to predict long-term dynamics will be restricted.     

丘陵红壤橘园不同地面管理措施的经济生态效益研究

在丘陵红壤橘园上．经过3年6种地面管理措施的经济生态效益研究。结果表明：（1）水土流失，以清耕法作对照，生草法、克无踪、草甘膦、草草克、克克草的地表径流量可显著减少分别为38．8％．42．5％．18，7％，28．7％和37．5％；土壤侵蚀量可显著减少分别为55．5‰，51．7％．39．9％．46．8％和50．0％；流失的氮磷钾养分总量可分别减少60．3％．50．2％，37．0％．41．8％和45．4％。（2）杂草再生率，以生草法做对照，则处理中的清耕法、克无踪、草甘膦、草草克和克克草分别是生草法的55．1%．67．2％．30．3％．36．8％和51．2％。（3）土壤肥力，以土壤OM，N,P2O3,K2O总量增减率看，清耕法为-4．4%,生草法7．1％，克无踪6．9％，草甘膦5．3％．克克草6．2％．草草克6．6％。（4）柑橘的产量和品质，以清耕法作对照，除生草法外，克无踪、草甘膦、草草克、克克草均增产7％～10％；可溶性固形物、总糖量、总酸度、糖酸比以及单果重均达到显著差异水平。克无踪调控杂草效果显著．可作为丘陵红壤丘陵园地水保与培肥兼得的有效地面管理措施。     

联吡啶类除草剂的作用机制及环境行为

介绍了以敌草快、百草枯为代表的联吡啶类除草剂的主要作用机制和选择机理,对该类农药在环境中的行为进行了归纳和探讨,指出该类除草剂对气候条件的影响并不特别敏感,挥发性亦不强,而与土壤的结合能力较强。展望了对其作用机制和环境行为的研究将进一步深入的前景。     

4种除草剂对紫花苜蓿-根瘤菌共生固氮的影响

在室内条件下,研究了乙羧氟草醚、三氟羧草醚、乙草胺和异丙甲草胺等4种除草剂对紫花苜蓿-根瘤菌共生固氮的影响。结果表明:4种除草剂均能对紫花苜蓿-根瘤菌共生固氮产生一定的抑制作用,其中以乙羧氟草醚的抑制作用最强,在高剂量下鲜重抑制率和干重抑制率分别为68.5%,70.6%,与对照植株的结瘤率和总含氮量92%和2.620%相比,其结瘤率和总含氮量为31%和0.072%;异丙甲草胺的抑制作用最弱,高剂量下鲜重抑制率和干重抑制率分别为18.5%和26.8%,与对照植株的结瘤率和总含氮量94%和2.136%相比,其结瘤率和总含氮量为60%及0.482%;紫花苜蓿经四种除草剂不同剂量处理后,总含氮量远远低于对照植株的总含氮量。