谨防棉花苗病春季,在棉苗出土的1个月内,如果土壤温度持续在15℃左右,甚至有寒流降温或阴湿多雨,多种棉花苗期病害就很容易发生,造成大量死苗。主要病害和防治方法有:一、立枯病俗称黑根病,主要症状是在近地面的茎基部产生黄色病斑,后变成黑褐色,并逐渐凹陷,腐烂子叶受害后形成 Beware cotton seedling disease in spring, within 1 month of cotton seedling excavated, if the soil temperature continues at about 15 ℃, or cold or rainy wet precipitation, a variety of cotton seedling disease is very easy to occur, resulting in a large number of dead seedlings. The main diseases and prevention methods are as follows: First, the dead blight commonly known as black root disease, the main symptoms are in the ground near the base of the stem to produce yellow lesions, after turning into dark brown, and gradually hollow, rotten cotyledons victims