稻瘟病穗瘟防治适期初探

本研究于2015-2016年对江苏沿江稻区水稻穗瘟不同防治时期病穗率防效和病指防效进行分析,发现防效与用药时间之间存在显著的二次或三次曲线关系。以两年的试验结果进行模拟的二次曲线方程理论值与实测值间的误差较小,方程的适合性较好。明确在前期雨水较多湿度较高时,应当适当提早用药,可将预防时间提早到破口日前5～7 d,以后再根据天气情况,决定是否再次用药防治;而在破口日前后降水较少的年份,则可等到破口日前5～6 d至破口40%进行防治。

A preliminary study on the suitable period for the prevention andcontrol of rice panicle neck blast

This study focus on the correlations between the control effects and the sprayed date of fungicide for rice blast at rice panicle stage in 2015 and 2016, Jiangsu Province. The result showed that the relationship of them could expressed as the conic or cubic equation, especially the conic equation has low errors between the theoretical value and the actual value. In the situation of more rain days and high humidity, the application of fungicides should be appropriate early than normal, 5 to 7 days ahead the rice breaking, on the contrary, the control time could be chosen from 5 to 6 days ahead the rice breaking to the day when 40% of rice breaking occurred.