Watermelon bacterial blight specific drug (with symptoms and incidence of law)

The specific drugs of watermelon bacterial leaf blight are chlorothalonil wettable powder, Sukeling wettable powder and mancozeb wettable powder. The main symptoms of watermelon bacterial leaf blight: first, there will be obvious water-stained dots on the back of the leaves, or between the veins, and when the humidity is high, it will lead to the loss of water in the leaves. The incidence regularity of watermelon bacterial leaf blight: the pathogenic bacteria will overwinter in the remnant tissue or seeds of the diseased plant, mainly transmitted by insects, and invade from the wound.

I. specific drug for bacterial leaf blight of watermelon

1. Soak the seeds in 55 ℃ warm water for 15 minutes, then soak the seeds with 75% chlorothalonil wettable powder or 50% prohydantoin wettable powder 1000 times for 2 hours, rinse with clean water and accelerate germination and sow.

2. Generally, in the early stage of the disease or before rainfall, 75% chlorothalonil wettable powder can be sprayed 500,600 times, 50% propofoin wettable powder 1000 times, and after the disease or when the humidity is high, 80% Dasheng Mmur45 wettable powder can be sprayed 600 times.

3. 1500 times of 50% Sukeling wettable powder and 70% mancozeb wettable powder can be sprayed with 60kg per mu, once every 5-7 days, 3-4 times continuously, and pay attention to make up spraying after rain and drain in time when there is water in the field.

II. Main symptoms of bacterial leaf blight of watermelon

1, first of all, there will be obvious water-stained dots on the back of the leaves, or between the veins, and when the humidity is high, it will lead to the phenomenon of withering of the leaves. When the weather is sunny and the temperature is high, it is easy to form 2-3mm round to near-round brown spots, covering the leaf surface, and in the later stage, the disease begins to become thinner and form withered leaves.

2. after the stem vine is infected, regret to produce fusiform or oval slightly sunken brown spots, and after the fruit is infected, regret that there are round brown sunken spots slightly raised around the fruit, which can go deep into the pulp, causing the fruit to rot and when the humidity is high, the diseased part grows a gray-black to black mildew layer.

3. Incidence regularity of bacterial leaf blight in watermelon.

The main results are as follows: 1. the general pathogenic bacteria will overwinter in the residual tissue or seeds of diseased plants, mainly through insects, invading from the wound, serious disease in the continuous cropping land and previous crop, and more bacteria in the soil; low-lying stagnant water and poor drainage; heavy clay and acid soil; excessive application of nitrogen fertilizer; cultivation is too dense, plants, interrow closure, not ventilated and transparent. Seed carrier, nutrient soil carrier for seedling, and organic fertilizer are not all mature or bacteria-carrying.

2, and early spring rainy or Meiyu comes early, the climate is warm, the air humidity is high; autumn is rainy, foggy, re-dew or cold snap comes early; greenhouse planting is often in order to keep warm without letting off wind and moisture, which is easy to cause excessive humidity. these situations will lead to bacterial leaf blight in watermelon.