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由于西瓜苗的猝倒病与立枯病(以下简称两病)症状非常相似,瓜农往往误诊而选错药剂防治,不但提高成本,而且易延误防治。因此,在西瓜育苗期一定要重视对这两病的防治。笔者根据几年来的种植试验,现将这两病的识别和防治方法介绍如下。一、症状识别1.猝倒病。苗期感染此病后,露出土表的茎基部或胚轴中部初呈水渍状,后变为黄褐色,病苗往往子叶尚未凋萎,幼苗即猝倒在地,一拔即断,病部变成黄褐色干枯或缩为线状,湿度大或气温高时,病部附近长出白色棉絮状菌丝。2.立枯病。主要为害地下根部或幼苗茎基部,初在病部现不规则形或近椭圆形暗褐色斑,病斑稍凹陷,病部扩展绕茎1周后致茎部萎蔫干枯,造成瓜苗死亡,但不折倒。根部感染此
As watermelon seedling damping-off disease and dead blight (hereinafter referred to as two diseases) symptoms are very similar, melon farmers are often misdiagnosed as the wrong medicine to prevent and control, not only to increase costs, but also easy to delay control. Therefore, in the watermelon breeding seedlings must pay attention to the prevention and treatment of these two diseases. The author according to several years of planting test, now the identification of these two diseases and prevention methods are described below. First, the symptoms identified 1. Dumping disease. Seedling infected with the disease, exposed the surface of the stem base or hypocotyl middle of the beginning was water-like, then turned brown, the seedlings often cotyledons have not yet withered, the seedling cataplexy in the ground, a pull that is broken, disease Department Into brown brown or shrink into a linear, high humidity or high temperature, the growth of white cotton wool near the diseased mycelium. 2. Blight The main damage to underground roots or seedlings stem base, the beginning of the disease is irregular or nearly oval dark brown spots, lesions slightly depressed, the diseased part of the stem 1 week after the stem wilted wilt, resulting melon death, but Do not fold down. Root infection of this