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近年来日光温室中番茄晚疫病发生严重,传播快,防治难,在生产上往往造成严重损失,甚至绝产。 一、症状表现 在幼苗期,子叶发病出现不规则暗绿色至褐色浸润状病斑,边缘有明显的霉层,逐渐向叶柄、茎部蔓延。初为水浸状,潮湿时出现白霉,并引起幼苗折倒枯死。成株期,从叶片的叶尖或叶缘呈现不规则的暗绿色水渍状病斑,后变为褐色,湿度大时,叶背面病、健部交界处有一圈白色霉状物,茎受害,开始暗绿色,后变黑褐色稍凹陷,病果不易脱落,潮湿时长出稀疏的白霉。 病菌以菌丝体在土壤中越冬,在田间形成中心病株后,病株上产生大量孢子囊,再随气流和雨水向四周扩散。低温高湿易发病。一般相对湿度在75％以上,气温15—25℃时,容易流行。
In recent years, tomato late blight in solar greenhouse occurs seriously, spread fast, difficult to control, often result in serious loss of production, and even absolute. First, the symptoms in the seedling stage, the incidence of cotyledon irregular dark green to brown infiltrative lesions, the edge of the mold layer was obvious, gradually to the petiole, stem spread. Early as flooded, white mold appears when wet, and caused the seedlings to fold down dead. Adult stage, from the tip of the leaves or leaf edge irregular dark green stains showed lesions, then turned brown, humidity, leaf back disease, Ministry of Health at the junction of a circle of white mildew, stem damage , Began to dark green, dark brown after a little depression, the disease is not easy to fall off, when the wet grow sparse white mold. Mycotoxins in the soil overwintering in the soil, in the field after the formation of the center diseased strains, the strains produce a large number of sporangia, and then with the air and rain spread to the surrounding. Low temperature and humidity prone to disease. General relative humidity above 75%, temperature 15-25 ℃, easy to pop.