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菠菜霜霉病是一种由鞭毛菌亚门散展霜霉菌引起的常发性病害。根据菜农发映,入冬以来,该病发生普遍,为害严重。尤以浇水过多,田间湿度大的田块,发病率高,受害重。一、发生规律。病菌以菌丝体在被害株内或以卵孢子在土壤中越冬,翌年经风雨传播为害。种子内混杂的病株残屑,为秋季、冬季发病的重要病源。当气温为7～16℃,在多雨多雾潮湿的环境下,被害部位发生大量的分生孢子,借风雨反复传播为害。这是造成田间病害蔓延的主因。在栽培条件上,连作由土壤中遗落的卵孢子数量多,初浸染源大,发病重。轮作田发病轻。秋菠菜播种越早,发病越重。低洼积水、密度过大、通风不良、植株衰弱的田块也易发病,初冬及春季发生较重。二、症状和诊断。主要为害叶片。受害部位初为淡绿色水渍
Spinach downy mildew is a disease caused by the proliferation of Flammulina submenis and downy mildew. According to vegetable farmers release, since the winter, the disease occurred widespread, serious damage. Especially watering too much field moisture field plots, the incidence is high, the victim. First, the law occurs. Mycelium in the victim strains or oospores in the soil overwintering, the next year by the spread of wind and rain damage. Seed mixed disease debris, autumn, winter onset of the important source of disease. When the temperature is 7 ~ 16 ℃, in a rainy, humid and humid environment, a large number of condyloma occurred in the affected area, which was repeatedly spread by wind and rain. This is the main cause of the spread of disease in the field. In terms of cultivation conditions, the number of oospores remained in the soil even in continuous cropping was high, and the primary source of dipping was large with severe morbidity. Wheel crop disease severity. Autumn spinach seeding earlier, the more severe the disease. Low-lying water, density is too large, poor ventilation, plant frail plots are also prone to disease, occurred in early winter and spring heavier. Second, the symptoms and diagnosis. The main damage leaves. Victims of the initial pale green water stains