4代棉铃虫发生程度影响因素的分析及其模糊预报研究

１９７４ ～１９９７ 年观测资料表明，影响４ 代棉铃虫发生程度的关键因素有：３ 代棉铃虫百株累计卵量，６ ～７ 月平均相对湿度，６ ～７ 月日降水量≥０ ．１ ｍ ｍ 的总日数，６ 月下旬～７ 月中旬（ 即梅雨期） 降水量，６ 月下旬～７ 月中旬温雨系数。根据相关性、时效性及稳定性原则，选取前３ 个因素作为预报因子，运用模糊综合评判法进行预报，历史符合率８７ ．５ ％ 。１９９８ 年试报准确。

The Factors Affecting on Fourth Generation Cotton Both Worm Occurrence and its Predication

The key factors affecting on fourth generation cotton boll worm occurrence were the number of third cotton boll worm egg per hundred cotton plants, relative humidity and days of rainfall≥0.1mm in June and July; the rainfall and the Coefficience between temperature and rainfall from the last ten day of June to second ten day of July through the analyses of data from 1974 to 1997. The first three factors were selected as the predication factors according to the relativity, time and effectivity, and stability. The predication result indicated the corrective ratio amounted to 87.5% in history and the predication was completely correct in 1998.