摘要
本文在解决了大田开放式接棉红铃虫实验技术的基础上,通过人工接虫;结合自然虫源和农药控虫等方法,形成棉红铃虫和朱砂叶螨以不同梯度组合的棉田复合危害系统。根据试验结果,运用逐步回归分析,建立了棉红铃虫和朱砂叶螨复合危害损失模型,阐明了“两红”复合危害损失规律。同时。建立了江汉平原棉区中等产量水平“两红”复合危害动态经济阈值模型,提出了“两红”复合危害防治指标。;n=18)…(4),将本试验各处理红铃虫累计卵量值代入…)式,计算出各处理的皮棉品级,据此,求得各处理的产量和产值,进而计算出产值损失率,组建“两红”复合危害的产值损失模型:以上结果表明,“两红”复合危害时,对棉花产值的影响均达极显著水平,朱砂叶螨主要是通过影响产量降低产值,红铃虫除对产量有一定影响外,更突出的是降低棉花品质而导致经济效益的降低。2.3“两红”复合危害动态经济阈值模型根据产值损失模型和经济阈值的定义[5.6]以及棉红铃虫和朱砂叶螨不同的防治费用和效果,推导出“两红”复合危害动态经济阈值模型:式中:XET1当朱砂叶螨级值为X2时红铃虫的经济阈值;XET2当红铃虫卵量为兄时朱砂叶螨的经济阈值;C1/PNF1为棉红铃虫的允许损失率;C2/PNF?
A technology to inoculate artificially pink bollwroms,.Pectinophora gossypiella,inopen cotton fields was developed successfully. By means of artiflcial inoculation of pest insects,various combination with different densities of pink bollworms and red leaf mites,T cinnabari-nus,were formed in combil1ation with the natural incidence of pests and chemical methods.Amodel that demonstrated their compound damages was worked out with gradual regression.Inaddition, the model of their dynamic economic threshold capable of being used in the cottonfields with ,middle yields in Jianghan district was established. Feasible dynamic economicthresholds of the two species were given。
出处
《棉花学报》
CSCD
北大核心
1994年第1期53-56,共4页
Cotton Science
基金
湖北省自然科学基金
关键词
棉红铃虫
朱砂叶螨
危害
棉花
pectinophora gossypiella(Saunders),Tetranychus cinnabarinus(Boisduval),compound damage,economic threshold