Recently, I went to the peanut field investigation and found that some peanut leaves appeared yellow and dead spots, and the front of the leaves appeared yellow-brown or dark brown spots. According to the symptoms of the plants, combined with current climatic conditions, it was diagnosed as peanut focal spot disease.

The diseased plant of focal spot disease occurs first from the lower leaves of the plant, and begins to experience disease at the tip of the lobule or at the edge of one side of the leaflet. The disease gradually develops chlorosis and changes from yellow to yellow-brown. Lesions from the leaf margin along the veins to the petioles extended into a wedge, and finally developed into a "V" shaped dead spots. The early lesions were gray-brown and the lesions that expanded after rupture were brown. The ascus of the pathogen presents a dense black spot on the dead spots, and eventually the entire leaf curls off. It can cause premature fall off of the middle and lower leaves of peanuts and affect the fullness of the pods. Generally, the yield is reduced by more than 10%, and severe plots can reduce production by 40%-50%.

solution:

1. Agricultural control. Rational rotation, timely removal of diseased leaves, implement deep plowing, in order to reduce the disease's initial infestation and reduce the spread of the spread of the disease.

2. Chemical control. 80% mancozeb WP 500 times liquid or mu with 10% WP water dispersible granules 50-80 g, spraying 40-60 kg water, 7-10 days interval, 2-3 sprays Times.

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