一、苗床死苗问题原因 :一是病害严重 ,主要有立枯病、炭疽病和枯萎病 ;二是施肥不当 ,用量过大 ,造成营养土浓度过高 ,种子或棉苗生长缺水造成烂芽、死苗 ;三是药害 ;四是高温烧苗和突然揭膜 ,造成生理失水死苗。措施 :精选健籽 ,药剂处理 ;合理用肥 ,钵土最好施腐熟人畜水粪 First, seedling dead seedlings cause of the problem: First, the disease is serious, there are blight, anthracnose and Fusarium disease; second is improper fertilization, the amount is too large, resulting in nutrient soil concentration is too high, seed or cotton seedling growth caused by lack of water Bud, dead seedlings; Third, injury; Fourth, high temperature burning seedlings and suddenly expose the film, resulting in physiological water dead seedlings. Measures: Select Jian seed, pharmaceutical treatment; reasonable use of fertilizer, pot soil is best applied to manure detritus