Symptoms and Control of Peanut net spot

Peanut net spot, also known as brown spot and moire spot, often occurs mixed with leaf spot, which can cause early peanut leaf shedding and seriously affect peanut yield. The symptoms show that reticular spot disease often occurs at the flowering stage, and the peak period is from podding stage to mature stage, which mainly harms the leaves. Round or irregular black-brown spots are produced along the main vein at the beginning, and there is a green halo circle around the disease spots. After that, irregular brown spots with reticulate edges appear on the front of the leaves, and millet brown spots can be seen in the diseased part. When it is overcast and rainy, the disease spot on the leaf surface is large, nearly round, dark brown, the disease spot on the back of the leaf is not obvious, light brown, the serious disease spot is fused; under dry conditions, the disease spot is easy to rupture and perforate. Once the leaves are infected, they fall off easily. The regularity of the disease is beneficial to the occurrence and prevalence of the disease in continuous rainy days. The land with high humidity in the field is prone to disease, and the disease is serious in continuous cropping land. Control methods to strengthen field management: increase the application of rotten organic fertilizer and phosphorus and potassium fertilizer, reasonable watering, timely ploughing, improve plant disease resistance, and remove the disease and residue in time after harvest. Chemical control: at the initial stage of the disease, spray control with 500 times of 70% mancozeb wettable powder, or 700 times of 75% chlorothalonil wettable powder, or 64% poison alum 500 times of wettable powder, once every 7 to 10 days, 2 times for 3 times.