立枯病又叫猝倒病,是苗木的主要病害。立枯病的症状分为四个类型:一是种芽腐烂型。即种芽出土前染病,组织腐烂死亡,苗床出现缺苗断垄。第二种是茎叶腐烂型。幼苗出土后染病,在叶片和苗茎上可看到白色丝状或灰色蛛网状物,几天之内茎叶就会粘结枯姜,腐烂死亡。第三种是幼苗碎倒型 Blight also known as damping off disease, is the main disease seedlings. The symptoms of blight are divided into four types: one is bud rot type. That germination of the disease before the emergence of buds, tissue decay death, lack of seedlings off the ridge. The second is stem-leaf decay type. Emergence of seedlings disease, the leaves and seedlings can be seen on the white filamentous or gray cobweb, stems and leaves within a few days will bind dry ginger, decay death. The third is broken seedlings inverted