棉花薄膜覆盖育苗,苗床管理中处理炼苗与保温的矛盾,一般采用日揭夜盖法.这种方法花工多,薄膜损坏率高,揭盖不当,容易形成僵苗、病苗和死苗.1980年我们设置了两个处理:1.通风不揭膜;2.日揭夜盖.各处理又分大小两个苗床进行对比观察.通风不揭膜苗床,除治虫、施肥、浇水外,昼 Cotton film covering nursery, seedbed management in the contradiction between hardening and thermal insulation, the commonly used method of exposure to the night .This method to spend more, the high rate of film damage, exposing improper cover, easy to form stiff, disease and dead seedlings In 1980, we set up two treatments: 1. Ventilation does not expose the film; 2. Reveals the night cover. Each treatment is divided into two sizes of seedbed for comparative observation. ,day