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从江苏省盐城市建立测报站二十多年的情况来看,近十五年的稻棉主要病虫害经历两次较显著的阶段性变化,其发生种类、频率、数量都有不同的特点。第一次转变出现在七二年前后,第二次转变出现在八○年前后。出现上述现象,主要与我市农业生产发展,在耕作制度、品种布局、栽培技术等方面的变化后,产生了一个不利于某些病虫发生、有利于某些病虫发生的环境所致。根据历史资料,面对当前实际,考虑“七五”期间农业生产布局的安排,对九○年以前稻棉病虫发生趋势作了分析,可能出现以下情况:(1)稻棉病害出现上升的趋势。(2)水
In the past 20 years since the establishment of the measuring station in Yancheng City, Jiangsu Province, the main pests and diseases of paddy and cotton underwent nearly two stages of significant changes in the past 15 years. The occurrence types, frequencies and quantities all have different characteristics. The first transition occurred around 1972 and the second transition occurred around 1980. The above phenomenon, mainly due to the development of agricultural production in our city, resulted in an environment unfavorable to certain pests and diseases and conducive to the occurrence of certain pests and diseases after the changes in farming system, variety layout and cultivation techniques. According to historical data, facing the current reality, considering the arrangement of agricultural production layout during the “Seventh Five-Year Plan” period and analyzing the trend of the occurrence of rice pests and diseases before 1990, the following may occur: (1) trend. (2) water