论文部分内容阅读
一、基本情况为害水稻的螟虫,随着我省栽培制度的改变,其种群及为害情况也随之发生变化。50年代以中稻为主,二化螟主要是第一代为害早栽水稻,第二代一般为害不重。由于水稻移栽期长达两月左右,迟栽稻田面积大,常遭受三化螟的严重为害,特别是第三代造成的白穗损失更重。60和70年代由于双季稻的发展,早、中、晚稻混栽,三化螟的为害更加突出。因此过去历年都是以三化螟为主要防治对象。自1978年以来,由于狠抓中稻并扩大了小麦、油菜面积,绝大部分稻区都实行“麦(油)——稻”两熟制。水稻的移栽期推
First, the basic situation Damage rice stem borers, with the change of cultivation system in our province, its population and damage situation also will change. In the 1950s, mainly in the rice, the second generation rice borer is mainly the first generation of damaged early rice, the second generation is not harmful. As the rice transplanting period of up to about two months, late rice fields are planted, often suffer serious damage by the yellow rice borer, especially the third generation caused more weight loss of white spike. Due to the development of double cropping rice in the 1960s and 1970s, the damage of the three stem borers was more prominent when mixed with early, middle and late rice. Therefore, all the past years are based on the three borer as the main control object. Since 1978, due to pay close attention to middle rice and expand wheat, rapeseed area, the vast majority of rice areas have implemented “wheat (oil) - rice” two cooked. Rice transplanting push