水稻稻粒黑粉病为害损失测定及防治指标的研究

稻粒黑粉病已成为杂交制种及不育系繁殖的一个重要病害。它对产量影响的直接原因是减少了单穗实粒重,增加了病粒率。分析结果表明,正常情况下的损失率应低于病粒率,每穗病粒数的多少对千粒重和结实率的影响不大。模拟为害发病率(X)与损失率(Y)的关系,可建立江农ⅡA/HR1004和汕A/桂33的损失预测方程分别为Y_1=-0.1036+1.0211X,Y_2=-0.0335+1.0528X。结合目前防治费用、产品价格和防治效果,本文估算了不同产量水平的允许损失率,并提出目前的防治指标为3％～5％。

Studies on Yield Loss and Control Index of Rice Kernel Smut

Rice kernel smut has become a major disease of the sterile line of hybrid rice. The direct reasons which cause the yield rate are that the disease decreases the grain weight per panicle and increases the rate of diseased grains. Results showed that the damage rate was lower than the rate of diseased grains. The thousand grain weight and the setting percentage had not relations with the number of diseased grains per panicle. Based on the relationship between rate of diseased grains and rate of yield loss of Jiangnong IIA/HR 1 004 and Shan A/Gui33 prediction models for loss were set,which are y1 = - 0. 1036+ 1. 0211x,y2= - 0. 0335+ 1. 528x,respectively. Otherwise,considering the cost of control, price of hybrid seed and efficiency of control, the paper proposed the allowable damage caused by rice kernel smut at different production levels, and control index which should be 3%-5% diseased grains.