蒜地除草最佳期的确定

蒜地除草最佳期的确定薛光（江苏省农科院植保所南京２１００１４）大蒜生育期长达２２０ｄ，蒜地杂草具有发生早，发生期长，发生量大的特点。为控制蒜地杂草的危害，蒜农往往需要３～４遍人工除草。在应用除草剂的地区，也需２～３次用药。选择最佳期进行蒜地化学除草，...     

蒜田杂草种群及防除

大蒜是我县传统经济作物之一,以味鲜、个大、洁白无瑕畅销国内外。因经济价值较高。每年种植面积达15～20万亩。但由于长期忽视对杂草的防除,加之近年来推广地膜覆盖后除草困难,致使蒜田草荒严重。据调查,地膜覆盖蒜田每年因杂草危害造成的损失达15～30％。因此,及时有效地防除蒜田杂草,是提高大蒜品质和产量的重要环节。1990～1992年我们对金乡县蒜田杂草的种类、群落结构、发生消长规律进行了调查,同时进行了化学除草技术试验研究。     

果尔蒜地除草技术研究

１９９２～１９９６年田间试验表明，１ｈｍ~２用果尔１７２．８ｇ（有效量）在大蒜播后芽前至立针期或２叶１心期至４叶１心期喷施，对蒜地杂草防效８６．４％以上，对大蒜安全。果尔１４４ｇ＋除草通２９７ｇ在大蒜播后盖膜前应用，对杂草株防效８７．４％以上，鲜重防效９５．３％以上。４ａ中示范果尔除草６万ｈｍ~２以上。     

大蒜田化学除草试验示范

对大蒜田间杂草进行除草试验示范表明,在大蒜播后苗前,每667m2施用果尔乳油30mL和40mL进行土壤喷雾,对大蒜出苗生长安全,除草效果好,蒜薹、独蒜和分蒜的产量、产值高,与人工除草相比,节约生产费用。     

蒜田杂草发生规律及化学防除

近年来,随着农业结构调整的深化和大蒜种植面积的逐年扩大,蒜田草害,特别是地膜蒜田草害严重影响大蒜的产量及品质。从2008年起,我们对蒜田杂草发生规律及防除技术进行了试验,取得了明显的经济效益及社会效益。     

蒜地杂草的化学防除

蒜地杂草种类繁多。禾本科杂草有看麦娘、硬草、野燕麦、早熟禾、马唐、旱稗等;莎草科有碎米莎草等;阔叶杂草有猪殃殃、播娘蒿、繁缕、小蓟、一年蓬、荠菜、婆婆纳、卷耳、泽漆、苣荬莱、蒲公英、蓼、扁蓄、碎米荠、飞蓬、大巢菜、野老鹳草、小旋花、鬼针草、泥糊莱、海滨酸模、圆叶锦葵等。 一、蒜地杂草危害特点 1、分季危害时间长 蒜生育期长达220多天,其全生育期中的杂草分早秋、晚秋、早春和晚春杂草4期危害。这些杂草长期与大蒜争水、争光、争肥,造成大蒜减产25％～60％。     

几种除草剂组合对蒜田杂草的防除效果

为明确不同除草剂对蒜田杂草防除效果和对大蒜的安全性影响,进行了禾本科杂草与阔叶杂草混生的常规草相蒜田和阔叶杂草占据优势种群的蒜田除草剂防效试验,结果表明：对于常规草相蒜田,以综合防治禾本科杂草和阔叶杂草为目的,可以选择7％草酮·16％乙草胺·12％乙氧氟草醚复配剂或30％二甲戊乐灵·10％乙草胺·4％乙氧氟草醚复配剂;对于以荠菜为优势杂草种群的蒜田,可选择24％乙氧氟草醚;对于以猪殃殃及其他阔叶杂草为优势种群的蒜田,可选择12％草酮。     

大蒜白腐病的识别与防治

大蒜白腐病的识别与防治大蒜是广西普遍栽培的冬种蔬菜品种，分肉蒜、骨蒜两大类型。肉蒜主栽品种为＂全州肉蒜＂，骨蒜主栽品种是＂玉林大蒜＂。大蒜白腐病在广西各大蒜种植区均有发生，对地上部份及地下部份都造成为害。亦可为害葱、韭造成损失。本病症状的出现包含从叶...     

中牟县首次发现根结线虫为害大蒜

1999年 1 1月中旬 ,调查蒜田病虫越冬基数时 ,在城关镇小潘庄、刘集乡大冉庄蒜田内均发现大蒜须根根尖上有畸形肿大现象 ,以前从未见过。今年 3月上旬 ,在官渡镇吴庄、大孟乡茶庵村蒜田内再次见到该症状 ,于是 ,拔些带土的蒜株 ,经室内剖根观察及病株根际土样冲洗测定 ,确认有根结线虫为害。据报道 ,根结线虫主要为害禾本科、葫芦科、豆科、茄科、伞形花科、菊科、十字花科等多种蔬菜及杂草 ,极少为害百合科。目前 ,国内有关根结线虫为害大蒜的报道资料甚少 ,在中牟县尚属首例。据田间观察 ,根结线虫为害大蒜时呈点片发生 ,主要为害大蒜须根…     

冬春早熟蒜地茎叶处理一次性化学除草技术探讨

随着农村产业结构的战略性调整 ,大理州冬春早熟大蒜生产迅速发展 ,1 999～ 2 0 0 0年度种植面积已突破 1万ｈｍ2 ,产值达 4～ 5亿元 ,成为本区新兴的支柱产业。由于冬春早熟大蒜播于秋季 ,光、温条件好 ,加之蒜地多为土质肥沃的旱地 ,因此 ,杂草种类多、数量大、生长迅速 ,人工薅除一般需 3～ 4次 ,花工较大。为了寻求冬春早熟大蒜规范的除草技术 ,1 997～ 1 999年 ,在摸清早熟蒜地杂草发生、为害特点的基础上 ,选用50 %乙草胺、2 5%绿麦隆、50 %扑草净、50 %敌草隆等药剂进行防除试验。结果看出 ,播后苗前土壤处理 ,前30～ 4 0ｄ内防效可…     

双条杉天牛幼虫人工饲料的筛选

双条杉天牛Semanotus bifasciatus(Motschulsky)是柏科树木最严重的钻蛀性害虫之一。开发双条杉天牛的人工饲料是开展该害虫防治技术研究及生物学相关基础研究的重要条件。本研究在参考了其他天牛人工饲料配方的基础上,采用正交试验设计方法设计饲料配方,通过对不同配方饲料对双条杉天牛幼虫的饲养效果进行比较和极差分析,最终筛选出双条杉天牛幼虫的人工饲料最优组合为:琼脂4.7%、蔗糖3.5%、对-羟基苯甲酸甲酯0.5%、酵母粉3.1%、柏树木粉30%、抗坏血酸0.5%以及水。使用该人工饲料可将双条杉天牛幼虫成功喂养至羽化,并且蛹羽化率高达81.25%,总成活率为54.16%。本研究的结果可为天牛科其他天牛人工饲料的开发提供借鉴。     

Botanical insecticides: for richer, for poorer

Botanical insecticides presently play only a minor role in insect pest management and crop protection; increasingly stringent regulatory requirements in many jurisdictions have prevented all but a handful of botanical products from reaching the marketplace in North America and Europe in the past 20 years. Nonetheless, the regulatory environment and public health needs are creating opportunities for the use of botanicals in industrialized countries in situations where human and animal health are foremost--for pest control in and around homes and gardens, in commercial kitchens and food storage facilities and on companion animals. Botanicals may also find favour in organic food production, both in the field and in controlled environments. In this review it is argued that the greatest benefits from botanicals might be achieved in developing countries, where human pesticide poisonings are most prevalent. Recent studies in Africa suggest that extracts of locally available plants can be effective as crop protectants, either used alone or in mixtures with conventional insecticides at reduced rates. These studies suggest that indigenous knowledge and traditional practice can make valuable contributions to domestic food production in countries where strict enforcement of pesticide regulations is impractical.     

杀菌剂生物测定动态评价时间-剂量-抑菌率模型

根据互补重对数数学模型的原理,建立了动态评价杀菌剂抑菌效应的时间-剂量-抑菌率模型,给出了模型参数估计和统计检验方法,并重点讨论了剂量的时间效应和不同时间段的剂量效应。最后提供了该模型的计算机算法实现和应用例子。     

Search for Climatic Models for Forecasting Microtine Outbreaks1

Models for forecasting outbreaks of harmful Microtines are discussed in terms of the three most important types of rodent damage to agriculture and forestry in the European part of EPPO region: problems to field crops by Microtus arvalis and related species, to horticulture and forestry by M. agrestis and some other species, and injury to the underground parts of various crops by Arvicola terrestris. Two models were developed in parallel but independently for M. arvalis, one in the USSR, the other in France; the former approach included M. socialis. A joint Scandinavian project resulted in models for M, agrestis and Clethrionomys glareolus: the outcome is exemplified by the former case and a few comments are given on other types of model development. The probable mechanism of climatic influence through the food chain on the population dynamics of Microtine rodents is discussed and it is concluded that climatic models are a useful tool in planning rodent control strategies. The role of the EPPO Working Party on Field Rodents as a coordinating body in the development of rodent forecasts is also reviewed.     

The search for new insecticides for tsetse fly control

Tests to evaluate candidate insecticides and formulations for tsetse control are described, and some data are presented to indicate that some new synthetic pyrethroids (e.g. permethrin and NRDC 161) are effective for a long period at such extremely low doses that they could have a pronounced influence on future tsetse control operations.     

Inverse modelling for estimating sorption and degradation parameters for pesticides

The leaching model PESTRAS was used to estimate sorption and degradation values for bentazone from three lysimeter datasets using the inverse modelling package PEST. Investigations were undertaken to assess the influence on calibration results of (1) values attributed to uncertain parameters not included in the calibration, and (2) starting values supplied to the inverse modelling package. Automatic calibrations with different realistic values for the Freundlich exponent n(f) yielded different combinations of K(om) and DT50. Similarly, the supply of different starting values for K(om) and DT50 revealed that different combinations of these two parameters equally calibrated PESTRAS for two of the three lysimeters. Examination of the error surface, ie the forward running of the model for different combinations of K(om) and DT50 values, and the calculation of the goodness-of-fit to the experimental data, was found useful for identifying those instances where non-uniqueness in the calibration is likely to occur. Although the derivation of sorption and degradation values through inverse modelling is expected to offer significant benefits over laboratory determinations, care should be exercised when examining values derived through this approach. Research is needed to identify data requirements for robust estimation of sorption and degradation parameters through calibration of pesticide fate models against leaching data.