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棉花枯萎病和黄萎病的症状类型较多,尤其是枯萎病和黄萎病往往同株混生,更增加了症状的复杂性。为便于识别,进行针对性的防治,现将田间常见类型描述如下,供参考。 一、枯萎病苗期症状: 枯萎病从子叶期即可发病,土壤菌量大的老棉田发病早。重病田现蕾前后出现发病高峰,造成大片死苗。苗期至现蕾期枯萎症状复杂多样,大致可归纳为五个类型。 1.黄色网纹型:病株子叶或真叶叶脉变黄,叶肉保持绿色,因而叶片局部或大部分呈黄色网纹状,然后叶片逐渐萎蔫枯干,脱落。 2.黄化型:子叶或真叶多从叶片边缘开始局部或大部分变黄,变黄的叶片逐渐增多,叶片萎蔫枯干,脱落。
Fusarium and Verticillium wilt symptoms of cotton are more, especially wilt and Verticillium wilt often mixed with the same strain, but also increased the complexity of the symptoms. For easy identification, targeted prevention and control, the field now common types are described below for reference. First, the symptoms of wilt disease Seedling: Fusarium disease from the cotyledons can be the incidence of soil bacteria in the early onset of cotton fields. Severe disease appeared before and after the onset of peak incidence peak, resulting in large dead seedlings. Withered seedling to budding complex and diverse symptoms, can be roughly divided into five types. 1. Yellow anilox type: diseased cotyledons or true leaf veins yellow, leaf green, so leaves some or most of the yellow reticulate, and then the leaves gradually wilting withered, fall off. 2. yellow type: cotyledons or true leaves and more leaves from the edge of the beginning of some or most of the yellow, yellowing leaves gradually increased, wilting withered leaves, fall off.