在棉花冷床育苗中经常会碰到这样一些不易解决的问题:首先是温湿矛盾,每天若苗床关闭时间过长,温度高,湿度大,棉苗容易长成绦线苗,即使经常变换通风口,也会产生局部僵苗和高脚苗;有的年份长期阴雨,棉苗病害严重,子叶脱落,以致死苗;春季大风频繁,掀动薄膜,管理麻烦,也影响效果。一九七五年我们在左夏二队采用有孔塑 In cotton cold bed nursery often encounter such problems are not easy to solve: First, the temperature and humidity conflicts, if the bed is off every day for too long, high temperature, humidity, cotton seedlings easily grow into sockets, even if the ventilation often change Mouth, will also have a partial stiff Miao and high seedlings; some years of long-term overcast, cotton seedling disease serious cotyledons off, resulting in death seedlings; frequent spring winds, tilt the film, the management of trouble, but also affect the results. In 1975 we used a hole in the second team left Xia plastic