小麦纹枯病危害损失及经济阈值的研究  

STUDIES ON WHEAT YIELD LOSS CAUSED BY SHEATH BLIGHT (RHIZOCTONIA CEREALIS) AND ECONOMIC THRESHOLD VALUE

作　　者：路兴波[1] 吴洵耻[1] 周凯南 

机构地区：[1]山东农业大学植保系

出　　处：《山东农业大学学报（自然科学版）》1995年第4期503-506,共4页Journal of Shandong Agricultural University：Natural Science Edition

摘　　要：通过对小麦纹枯病（Ｓｈｅａｔｈｂｌｉｇｈｔ）不同病级和病情指数与产量损失的研究表明：小麦孕穗期病级与小麦千粒重和产量呈线性相关，产量损失率（ｙ）与收获前病情指数（ｘ）呈幂函数关系，当ｘ＜２０时．ｙ＝０．１８０７５ｘ１．１２７０２５（ｒ＝０．９７７０，ｎ＝１６），当ｘ＞２０时．ｙ＝０．１１０５Ｘ１．３５１５７５（ｒ＝０．９９８３，ｎ＝１２），根据病情指数与产量损失率的关系，得到纹枯病经济阈值的动态模式，即：在目前小麦产量６～７．５ｔ／ｈｍ２水平下．建议防治指标病情指数为３．０～６．０，即经济允许损失水平控制在１．４％以内．Relationship of different disease grades and disease index to yield loss indicates alinear function between 1.000-grain-weight and disease grades of ear-bearing stage.Cikedisease index. there is a power function between the disease index (x) and the yield loss (y)rate. The functional equation can be expressed as y=0.18075x1.127025 (r=0.9770. n=16).when x< 20. But when x is bigger than 20.the equation turns into: y=0. 1 105x1.351575(r = 0.9883. n = 12). According to relationship between the yield loss and disease index. combining the grain yield(N).the wheat price(C).efficienty of chemical control(E) and the cost of control(B).a dynamic model of economic threshold (ET) for the wheatsheath blight is proposed as:Based on the results. it is suggusted that at the level of grain yield (6～7.5 t / hm2) atpresent. the index of chemical control should be 3.0～6.0 for the disease index. the yield lossshould be kept between 0.7 and 1.4 %.

关 键 词：小麦 纹枯病 经济阈值 病情指数 

分 类 号：S435.121.4[农业科学—农业昆虫与害虫防治]