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玉米螟为害玉米对产量损失的影响经邱式邦、吴维均、李国柱等(1964)研究,认为心叶末期被害较穗期影响产量显著为大,在穗期或乳熟期为害的幼虫对产量影响不大或甚至没有影响。所以认为当前应用颗粒剂防治玉米螟,提倡在心叶末期施药一次,不仅从防治效果(减少虫数)上看是适当的,从保证产量的角度来看也是有利的。因此,要正确检定防治效果,必须在抽雄后或开花期进行虫口密度检查,此时幼虫密度能代表心叶末期的为害,可以作为检定防治质量的标准,而在抽穗以后进行检查,则不能正确反映对产量的影响。 但是,在抽雄或开花期调查虫口密度,必须剖开植株才能检查。根据作者的研究,玉米螟幼虫的田间分布是不均匀的(经测定符合核心分布和负二项式分布),要较准确的进行抽样调查,必须剖查大量的玉米植株才能达到目的,这样对生产不但带来较大损失,而且又很费工,不易推行。因此,如何精确而又节约的检定防治效果是否符合要求,这是在大面积防治玉米螟
Effect of corn borer corn on yield loss By QiuBangBang, wuWeijun, LiGuoZhu et al (1964) study, that the end of leaf damage at the end of the yield significantly affected than the large, larvae in the ear stage or milk ripening impact on the yield Little or no effect. So that the current application of granular control corn borer, the promotion of the end of leaf application, not only from the control effect (reduce the number of insects) point of view is appropriate, from the perspective of ensuring yield is also beneficial. Therefore, in order to correctly test the effect of control, the density of insects must be checked after tasseling or flowering. At this time, the density of larvae can represent the damage of late leaf end, which can be used as the standard to test the quality of prevention and control, but can not be correct after heading Reflects the impact on production. However, surveying insect population density during tasseling or anthesis must be dissected before plants can be examined. According to the author’s study, the field distribution of corn borer larvae is not uniform (measured in line with the core distribution and negative binomial distribution), to be more accurate sampling survey, we must examine a large number of corn plants in order to achieve the goal, Production not only brings greater losses, but also very laborious and difficult to implement. Therefore, how accurate and economical test control effect meets the requirements, which is in a large area to control corn borer