病虫发生表征新方法--为害指数的定义与应用

为害指数(PAI)是一种反映和评价农业病虫害严重性的新方法。它将常规调查的发生密度(为害率)、发生面积简化成为单一的概念性数值形式,并据此划定发生程度等级,适用于表述县级以上地区短期病虫为害状况和趋势。PAI定义:在某一时段中,害虫(病害)的密度指数与面积指数的乘积,而密度指数为病虫单位面积的发生密度(发病率)占防治指标(或历年密度均值)的倍数,面积指数为病虫发生面积(率)占历年发生面积(率)均值的倍数。     

昭平县稻瘿蚊发生为害逐年减轻的原因分析

文章阐述10多年来昭平县稻瘿蚊的发生概况,并根据其发生规律和发生特点进行分析,认为昭平县稻瘿蚊自2000年以来发生程度逐年减轻。其原因有：一是耕作制度改变,降低了越冬虫源;二是塑盘抛秧栽培新技术,抑制了稻瘿蚊的发生;三是除草剂及高效、长效农药的科学使用;四是田间管理水平得到了很大的提高;五是稻瘿蚊的天敌得到了一定的保护。     

竹节虫为害玉米的初步观察

宜都市地处丘陵低山,常年种植玉米１万ｈｍ２以上,１９９７、１９９８年部分乡镇发生一种竹节虫（经分类检索属昆虫纲虫目棒虫科）为害,取食玉米叶片造成严重损失。其中毛湖淌、潘家湾两乡发生面积０．１万ｈｍ２,占玉米种植面积的４２．９％,最严重的田块产量损...     

古浪县平川灌区胡麻的枯萎病发生为害及综合防治

古浪县平川灌区胡麻的枯萎病发生为害及综合防治甘国福（甘肃省古浪县农业技术推广中心７３３１００）胡麻是我县平川灌区的主要油料作物，近年来胡麻发生枯萎病普遍且日趋严重，为此，我们于１９９０年起对胡麻枯萎病的发生为害及其防治技术进行了调查研究。一、发生为害...     

沿江混栽稻区二化螟近年发生为害特点与治理对策

近十年来，二化螟种群迅速上升。据宿松县30a螟虫发生为害测报调查资料分析，水稻二化螟近年发生特点是越冬场所广，基数大；发育极不整齐，蛾峰多，盛发期长；为害时间长，转株为害严重，被害症状多；三代发生为害加重。据此提出了防治对策。明确减少越冬虫源、秋收灭茬、科学管水、合理施肥等农业措施的防治作用。提出药剂防治一代二化螟应改一次施药为一次重点，重发区补治、挑治。明确在新的发生情况下，各代的防治对象田、防治适期和防治指标。     

大螟的转移为害规律及其测报技术探讨

通过系统调查大螟的寄主范围，明确了大螟在不同寄主植物上的转移为害规律，并将大螟的发 生分为侨居代、繁殖积累代和主害代。在明确各发生代主要虫源的基础上，提出了虫情预测的技术要点。     

防止福寿螺扩散蔓延

1990年6～7月间,我们曾到闽北山区沙县的4个乡镇3个农场进行有关福寿螺Ampullarium canaliculatus的实地调查,并将采集到的福寿螺带回福州,置于水缸中饲养,观察其发生世代、生长繁殖规律。综合有关资料分析,认为福寿螺将在我省局部地区对农业生产造成隐患的可能性。     

1991年广西水稻主要病虫鼠发生为害实况

1991年我区水稻病虫的总体发生程度属中等、局部偏重年份。全年水稻病虫鼠发生面积为632.62万公顷(次),占水稻种植面积的262.3％,比上年(历史最高年)的650.64万公顷(次)减少2.8％,防治面积639.74万公顷(次),占发生面积的101.1％。若不实施人为防治,可造成稻谷产量损失227.85万吨,经防治后挽回稻谷损失183.89万吨。其     

棉铃虫猖獗为害的原因与对策

棉铃虫猖獗为害的原因与对策王玉堂（山东省东平县农委２７１５００）近年来，各棉区棉铃虫的为害明显加重，时有特大发生的报道。１９９２年，棉铃虫在全国发生达１．８９亿亩次，减产皮棉４０万吨，直接经济损失６０多亿元，棉农人均减收约６０元。一、猖獗为害的原因分...     

小麦条锈病在西藏的发生为害特点及综合防治策略

小麦条锈病是西藏小麦上主要病害之一。从侵染循环、病菌群体结构、发生区划、为害情况等方面揭示了该病在西藏的发生规律及为害特点。分析了该病在西藏流行的温、湿度条件、小麦品种、桥梁寄主等因素。认为小麦主栽品种抗源单一、抗性差、菌源面积大以及锈菌新的生理小种不断产生等是小麦条锈病在西藏流行的主要原因,并通过对小麦条锈病在西藏发生为害特点的分析,针对性地提出了综合防治策略。     

禾谷孢囊线虫(Heterodera avenae)的分子鉴定及抗性基因研究进展

禾谷孢囊线虫是温带禾谷类作物上的世界性重要病原线虫。本文回顾关于禾谷孢囊线虫的分子鉴定和亲缘分析等方面的研究,以及对国内外小麦品种抗性基因的筛选和应用等结果。根据上述方面的结果拟定更为合理的防治策略。     

Genetic relationships and isozyme variability in the Heterodera avenae complex determined by isoelectrofocusing

Isozyme variability was assessed among the principal species of the cereal cyst nematode complex to complete and enhance the information provided by classical nematode systematics, in order to clarify inter- and intraspecific relationships within this complex. Twenty populations of cereal cyst nematodes ( Heterodera avenae , H. filipjevi , H. latipons and H. mani ) were compared by means of five different isoenzymatic systems (esterase, malate dehydrogenase, phosphoglucoisomerase, phosphoglucomutase and superoxide dismutase) using isoelectrofocusing (IEF) on the electrophoretic separation. The results are in agreement with previous morphological and biochemical characterizations, which established genetic diversity between the Gotland strain and H. avenae and identified the Gotland strain with H. filipjevi . Populations from Israel, all included in the H. avenae group, exhibited well-defined intraspecific dissimilarity. The highest degree of polymorphism was found in the H. avenae group for all five enzymatic systems studied. The H. mani population was also included in the H. avenae group by these isozyme analyses. Malate dehydrogenase, phosphoglucoisomerase and phosphoglucomutase isozymes, fractionated for the first time by IEF in the cereal cyst nematode complex, displayed a higher level of polymorphism than using conventional electrophoresis. Isoelectric focusing has proved to be a useful tool for detecting genetic diversity within and among species of the cereal cyst nematode complex and for taxonomic purposes.     

The Status of Heterodera avenae on Cereals in New Zealand1

The cereal cyst nematode (Heterodera avenae) was discovered in New Zealand in 1975 on wheat and oats. It was not at that time causing appreciable economic losses in yield, presumably because usual management practice incorporated a good crop rotation with lucerne. However, now that the growing of cereals has become more profitable, farmers are tending to grow consecutive cereal crops and more damage from H. avenae is being experienced. On one farm, up to 9 % of an oat crop was lost due to this nematode. The biotype has not yet been determined.     

小麦对小麦孢囊线虫抗病性研究进展

由小麦孢囊线虫引起的小麦孢囊线虫病发生分布范围广,防治困难,严重危害我国小麦生产.在我国危害小麦的孢囊线虫主要包括禾谷孢囊线虫(Heterodera avenae)和菲利普孢囊线虫(H.filipjevi).种植抗病小麦品种是防治小麦孢囊线虫病最经济有效的措施,近10年来,我国科学家制定了小麦孢囊线虫抗性评价标准,测试...     

不同药剂拌种对小麦根腐病和孢囊线虫病的防效

 在田间条件下研究了150 g·L^-1苯醚·阿维·吡等10种药剂拌种对小麦根腐病和孢囊线虫病的防治效果。结果表明:30 g·L^-1苯醚甲环唑和60 g·L^-1戊唑醇拌种处理对小麦根腐病防治效果分别为73.9%和66.2%,但二者对小麦孢囊线虫无防治效果;50 g·L^-1阿维菌素和140 g·L^-1阿维·吡拌种处理后,土壤中校正孢囊减退率分别为58.4%和69.2%;使用600 g·L^-1吡虫啉拌种对孢囊线虫未见明显防治效果,但吡虫啉能对阿维菌素的杀线作用有一定增效作用;复配剂150 g·L^-1苯醚·阿维·吡和160 g·L^-1戊·阿维·吡对小麦根腐病和小麦孢囊线虫病防治效果较好,二者对小麦根腐病防治效果分别为75.6%和63.8%,校正孢囊减退率分别为71.3%和74.1%;从增产效果来看,150 g·L^-1苯醚·阿维·吡拌种后小麦增产效果最好,平均产量为7 869.9 kg·hm^-2,增产率为8.6%。综合药剂安全性、防病效果和增产效果,150 g·L^-1苯醚·阿维·吡适合在生产上防治小麦根腐病和孢囊线虫病。     

Interactions between Heterodera filipjevi and Fusarium culmorum,and between H. filipjevi and Bipolaris sorokiniana in winter wheat

Journal of Plant Diseases and Protection - Pot experiments with winter wheat were conducted for two successive years to study the relationship between the cereal cyst nematode, Heterodera...     

Influence of temperature and storage conditions on the hatching behavior of cereal cyst nematodes (Heterodera avenae Wollenweber) from Egypt

Journal of Plant Diseases and Protection - The cereal cyst nematode Heterodera avenae has been reported in wheat fields in Egypt; however no information is available on the hatch of second-stage...     

Estimation of Loss in Wheat Yield Due to the Cerealcyst Nematode Heterodera avenae

Abstract

The cereal cyst nematode, Heterodera avenae Wollenweber, 1924, occurs worldwide including India where it causes ‘molya’ disease of wheat and barley. Wheat yield losses due to the nematode were estimated during 1974-76 at a few villages in Mohindergarh district, Haryana, India, by applying dichloropropane-dichloropropene mixture and dibromochloropropane singly or in combination as soil f umigants. In light soil the cereal cyst nematode infestation at 4/5 eggs and larvae/g soil approximated the economic threshold level. However, depending on the initial population density of H. avenae and other field conditions, such as soil type, moisture, soil condition, chemical application method, chemical application time etc., the increase in yield of wheat cv. Kalyan Sona ranged from 8 to 49% at nematode infestation levels of about 6 to 13 eggs and larvae/g soil when treated with these nematicides.     

小麦禾谷孢囊线虫湖北群体活动期特性

小麦播种时定量接种禾谷孢囊线虫（ＣＣＮ）（Ｈｅｔｅｒｏｄｅｒａａｖｅｎａｅ）的孢囊,发芽生根后进行系统观察,结果表明,该线虫在小麦生长季节中完成１代,小麦播种后２５～３５ｄ是２龄幼虫入侵幼根的高峰期,１００～１２０ｄ根内出现３龄幼虫,１１０～１３０ｄ发育成４龄幼虫,１３０～１５０ｄ根表露出白色孢囊（雌虫）。受感染的麦根,侵染点首先变褐,进而肿大,常见分叉增多,形成须根团,ＣＣＮ多居于自然含磷,钾元     

不同土壤质地对禾谷孢囊线虫侵染及种群动态的影响

为明确不同土壤质地对禾谷孢囊线虫Heterodera avenae发生危害的影响,分别测试了6种土壤质地中禾谷孢囊线虫的侵染、发育及其种群动态。结果显示：在整个小麦生长季,不同土质中禾谷孢囊线虫2龄幼虫（J2）的种群变化趋势一致。冬前土壤中少量线虫孵化,11月下旬各种土质中J2种群密度达到10.8~14.2条/100 mL土壤;4月初为J2发生高峰期,其种群密度为54.6~77.1条/100 mL土壤,且土壤中含壤土比例越高J2数量越大;J2在壤土与砂土比为6：1和1：0土壤中侵入根系的数量最多,单株根系J2数量为672.7~685.0条,且土壤中砂土比例越大J2侵入数量越少,相应地根系内3龄幼虫和形成的孢囊数量也越少;不同土质中不同时期孢囊内虫口减退率不同,但在生长季末不同土质中孢囊内虫口总减退率无显著差异。研究表明,土质对孢囊内虫口减退率无影响,土质沙性越大越不利于禾谷孢囊线虫的发生危害。