灰飞虱及条纹叶枯病对水稻产量的影响及其防治指标的制定

在灰飞虱成虫带毒率39.4%的基础上，对水稻品种武粳15和武运粳7号进行了罩笼接虫试验，结果表明：水稻条纹叶枯病发病率与灰飞虱接虫量呈显著的正相关关系；另外，灰飞虱接虫量与水稻的有效穗、结实率和产量均呈显著的负相关关系，与水稻的产量损失率呈显著的正相关关系；对于武运粳7号和武粳15，灰飞虱虫量（x）与产量损失率（y）的线性回归方程分别为：y=0.0699＋2.81x、y=0.2648＋1.84x。由此建立了这两个水稻品种上灰飞虱虫量的防治指标：对于武粳15，防治指标为16900头/667 m^2，对于武运粳7号，防治指标为11400头/667 m^2。

Effects of Laodelphax striatellus and Stripe Disease on Yield of Rice and Establishment of Their Control Threshold

Laodelphax striatellusadults with the virus carried rate of 39.4% was transplanted to plants of Wujing 15 and Wuyunjing 7.The results showed that the incidence of stripe disease was positively correlated with the number of inoculated Laodelphax striatellus;and the number of inoculated Laodelphax striatellus was negatively correlated with the number of the efficient tillers,setting rate and the yield of rice,positively correlated with yield loss.For Wuyunjing 7 and Wujing15,the relationship between the number of Laodelphax striatellus(x) and the yield loss(y) could respectively be expressed with the following regressive equations: y=0.0699 2.81x,y=0.2648 1.84x.The control thresholds were estimated on different varieties,which was 16900 heads/667m2 and 11400 heads/667 m2 for Wujing 15 and Wuyunjing 7,respectively.