赤霉病为本市麦类生产的重要病害之一,其流行程度主要取决于前期的气象条件。为提高预测的准确性,对本市1973～1986年共14年的发生资料,经电算筛选,选取了影响大麦赤霉病发生程度的三个相关显著的因素:上年7月份平均最低气温(x_1),上年12月份雨日天数(x_2),和上年12月下旬的最低气温(x_3)。将预报值及这三个因素皆分成3级。所建立的回归预测式为 Fusarium head blight is one of the most important diseases of wheat production in this Municipality. The prevalence of blight is mainly determined by the meteorological conditions of the early stage. In order to improve the accuracy of prediction, three significant factors that affected the occurrence of FHB in the city from 1973 to 1986 were selected by computerized screening. The average minimum temperature in July last year x_1), the number of rainy days in December last year (x_2), and the lowest temperature (x_3) in late December last year. The forecast value and these three factors are divided into three levels. The regression formula is established