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随着栽培技术的改变和水肥条件前不断提高,近几年来,棉铃虫成为我省棉花蕾铃期的主要害虫,对棉花稳产、高产威胁极大。一、发生特点及其分析一九七二年棉铃虫在我省是个大发生年,七三年次之,七四年为中等偏重发生年。此虫在我省一年发生五个世代(少数棉区有不完全的六代)。第一代主要在棉田外的小麦、豌豆、草子等寄主植物上为害,第二至五代多在棉田内,常年以第四、五代发生量大,但到第
With the change of cultivation techniques and the continuous increase of water and fertilizer conditions, in recent years, the cotton bollworm has become the main pest in cotton bud bolling period in our province, threatening cotton stable and high yield. First, the occurrence characteristics and analysis Helicoverpa armigera in 1972 is a big occurrence in our province, followed by seven or three years, four or four years for the middle of the year. This pest occurs in our province five generations a year (a few cotton areas have an incomplete six generations). The first generation is mainly on the host plants such as wheat, peas, grass and other plants outside the cotton field, the second to fifth generation mostly in the cotton field, perennial in the fourth and fifth generation occurred large, but to