分档统计法在烟草赤星病流行趋势预测上的应用

Applying grade-statistics method to forecast occurrence trend of Alternaria alternata (Fries) Keissler

以宁远县连续9年的资料为基础,利用符号法从31个自变量中选取出烟草移栽后第2个月雨量(mm)、同期平均气温(℃)及移栽后1个月内雨日数作为烟草赤星病流行趋势的3个预报因子。以分档统计法进行预报,结果表明:9年回检值与实际值均完全符合;用于异地15年次预测(实际上为回测),准确率达80%。本法可在此病流行前提前约1个月做出预报。

Rainfall （ram） of the second month after transplanting, average temperature （℃） at the same period, and rainfall days of the first month after transplanting were selected from 31 factors using anomalous sign method from data in 9 continuous years in Ningyuan county. Alternaria alternata （Fries） Keissler occurrence trend was studied with grade-statistics method. Re- sults showed that back forecasting was in line with the actual value. The accurate percent of forecasting for Alternaria alternata （Fries） Keissle at different counties for 15 years was over 80% . The grade-statistics method can be used to forecast occurrence trend of Alternaria alternata （Fries） Keissler one month in advance.