我区地处川北丘陵,自然灾害频繁。在杂交玉米制种的中后期,一是遇到霖雨天气,影响正常授粉结实;二是由于春、中玉米的花粉已经结束,粮食作物中只有制种玉米的迟父本正在散粉,因此蜜蜂、蚜虫等集中偷粉危害;三是频繁的山风吹落花粉。使母本后期抽出的果穗和先出果德的上部花丝无粉可授,形成秃尖、缺粒或空秆而减产,据试验每亩将少收20—50公斤杂交种子。为此,我们经过1985—1987年三年的实践经验和1988年的进一步运用检验。在杂交玉米制种大量扬花授粉的中后期,遭到上述不利因素影响时,将迟父本搬挖回室内集中采花人工授粉,是一项趋利避害提高杂交玉米结实率的补救措施。一般能提高结实率36％左右,增产 My area is located in northern Sichuan hills, frequent natural disasters. The second is because of the pollen of spring and middle maize is over, only the late father of the corn that is planted in the grain crops is being loosened, so the bees, Aphids and other places to steal powder hazards; Third, frequent blowing down pollen mountains. So that the female parent after the early extraction of fruit and the first German-made top filiform powder-free grant, the formation of bald tip, lack of grain or empty stalk and cut, according to the test will receive 20-50 kg less per acre hybrid seed. For this reason, we have passed the three years of experience in 1985-1987 and the further tests of 1988. In the mid-late hybridization of corn seedling pollination, suffered the above adverse factors, will be the late father moved back to the indoor artificial flower picking flowers, is a trend to avoid damage to improve the rate of hybrid corn seedling remediation measures. Can generally improve the seed setting rate of about 36%, increase production