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1988年早春,我们对我县163亩面积的圆葱紫斑病进行了普遍观察和防治。下面将本县圆葱紫斑病的发生及防治情况作一简略介绍。一、圆葱紫斑病的症状表现症状:圆葱紫斑病主要危害叶和花梗,病斑多从外围老叶的尖端或上半部发生。初生病斑很小,大小为2—4×1—3(厘米),早中期多为2×3(厘米),稍凹陷,多呈紫褐色或边缘带紫色,常形成同心轮纹。病斑呈椭圆形或纺锤形。潮湿时病斑上生有黑霉。发病严
In the early spring of 1988, we conducted a general observation and prevention and cure of the onion purpura, which covers an area of 163 mu in our county. The following will be the occurrence of the county onion purpura and prevention and treatment of a brief introduction. First, symptoms of onion purple spot Symptoms: The main hazards of onion purple spot leaves and peduncles, spots and more from the outer edge of the tip or the upper half occurred. Primary lesion is very small, the size of 2-4 × 1-3 (cm), early and mid-term more than 2 × 3 (cm), slightly depressed, mostly purple brown or purple edge, often forming concentric ring pattern. Lesions were oval or spindle-shaped. There are black molds on damp spots. Sickness