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1981年5、6月,据南汇、青浦、金山、上海等县植保站及公社农科站反映,不少移栽棉花发生棉苗腰拆现象。为此,我们在青浦赵巷三队进行了初步调查,发现病害较为严重,大片棉田缺苗断垄。在220株棉花中,发病的46株,折断枯死3株,发病率22.27％。田间症状:棉苗腰折多发生在4片真叶至现蕾初。病株下部二片真叶沿叶片主、侧脉有角斑病病斑,黑褐色,透明,油渍状;叶尖部分呈黄、红色,干枯。病斑由叶脉经叶柄蔓延到基部,环状扩展包围基秆,叶柄及茎部变细、弯曲,呈黑色,严重时折断枯死。也有部分病株的病斑不是由叶柄向下延伸,而是茎秆上直接出现水渍状病斑,以后逐渐扩
May and June 1981, according to Nanhui, Qingpu, Jinshan, Shanghai and other county plant protection stations and communes Agricultural Station, many transplanted cotton Mianmiao demolition occurred. To this end, we conducted a preliminary investigation in the third team of Zhao Lane in Qingpu and found that the disease was more serious. Among 220 cotton plants, 46 were morbidly infected, 3 were broken and died, the incidence was 22.27%. Symptoms in the field: Mianzhu waist fold occurs in 4 really leaves to bud early. The lower part of the diseased plant leaves two true leaves along the main leaf, side veins angular spot disease, dark brown, transparent, oil-like; tip part of the yellow, red, dry. The lesion spread from the veins through the petiole to the base, surrounded by ring-shaped extension of the base stalk, petiole and stem thinning, bending, black, severely broken off. There are also some diseased lesions not from the petiole extending down, but directly on the stem water stain-like spots, and gradually expanded