小麦赤霉病气象条件适宜程度等级预报

Prediction of the adaptability category of meteorological conditions for wheat head blight

利用1965—2006年气象、赤霉病资料,分析赤霉病感病期间各气象要素对赤霉病的诱发程度,定义满足一定诱发条件的日子为赤霉病诱发致病日。根据最优化技术二维寻优的变量轮换原理,计算赤霉病感病期间逐日诱发修正系数、赤霉病诱发致病日的持续时间修正系数,建立促病指数模型,由此判别赤霉病气象条件适宜程度及发生的等级。2007年、2008年和2009年试报结果与实况相符。应用本研究方法,可动态监测赤霉病气象条件适宜程度的等级,由此推测赤霉病可能流行的程度,科学防治赤霉病。

The effects of individual meteorological variables on wheat head blight outbreak during the period of feasible wheat head blight infection were investigated using historical data of meteorology and state of wheat head blight during the period from 1965 to 2006 for the region south of Huaihe River, Jiangsu province. A day with meteorological conditions favorable for the infection and outbreak of wheat head blight is defined as the inducing-day of wheat head blight. The cyclic variable method of two-dimensional optimization was used to determine two coefficients, which correct the effects of the date and duration of inducing day on the seriousness of wheat head blight, respectively. These correction coefficients were integrated into a model calculating the inducing-index of wheat head blight. Adaptability of meteorological conditions for wheat head blight and the possible occurrence category of wheat head blight were determined according to the calculated inducing-index. In 2007,2008,2009, the occurrence categories predicted by the model agreed with measurements well. The algorithm developed in this study can be practically used to dynamically monitor the adaptability of meteorological conditions for the infection and outbreak of wheat head blight and prediet the possible seriousness of wheat head blight. It can act as a useful tool for the prevention and control of wheat head blight.