大葱是雌雄同花,异花授粉植物,主要靠昆虫传粉。近年来,由于田间和果园大量使用杀虫药,致使田间蜜蜂及其他昆虫数量大大减少,再加之在大葱花期常常遇到连续几天的干热风,使大葱得不到充分的授粉。一般亩产葱籽仅15—25公斤左右。为了弥补自然授粉不足和减轻不良气候的危害,需要采取以下几项措施。 Scallions are monoecious, cross-pollinated plants, mainly by insect pollination. In recent years, due to extensive use of insecticides in fields and orchards, the number of bees and other insects in the field has been greatly reduced, and the green onions have not been fully pollinated due to the frequent dry hot winds encountered in green onions for several days. Generally only 15-25 kilograms of onion per mu. In order to make up for the lack of natural pollination and mitigate the harmful effects of bad weather, the following measures need to be taken.