论文部分内容阅读
北京市通县从1965年开始推广杂交玉米以来,现杂交玉米种植面积已达玉米总面积的85％以上。多年的生产实践告诉我们,推广杂交玉米生产上很起作用,但必须做好防杂保纯工作。1975年以前,由于我们对杂交玉米防杂保纯工作不够重视,一个新的组合,最多种植三到四年就混杂退化的不成样子了,用群众的话来说就是:“头年纯,二年杂,三年就退化”;“只能做客,不能安家”。从1975年开始,我们狠抓了防杂
Tongxian County, Beijing since 1965 to promote hybrid corn, hybrid corn acreage now reached 85% of the total area of more than. Years of production practice tells us that the promotion of hybrid corn is very useful, but we must do a good job in prevention and control of impurities. Before 1975, due to the fact that we did not pay enough attention to hybrid corn prevention and control work, a new combination of up to three to four years of planting is incoherent with mixed degeneration. In mass terms, “the first year of pure and two years Miscellaneous, three years on the degradation ”;“ can only be a guest, can not be home. ” Since 1975, we have paid close attention to preventing miscellaneous things