Anthracnose is one of the common major diseases of watermelon. The disease is widespread in the watermelon growing areas in the country, especially in the rainy areas in the south, and it is the main disease affecting the stable production, high yield and high quality of watermelons.
First, the incidence of symptoms of watermelon anthracnose from seedlings to mature, in the leaves, vines, fruits can occur. When the seedlings were onset, the near-surface vines turned dark brown and collapsed. When the leaves are damaged, they begin with a small, yellow, water-stained, round spot that later expands to become brown. There is a purple-black circle around the lesion, on which a small black spot or pink sticky material grows. The lesion gradually enlarges, connects each other into pieces, and crushes when dried, causing the leaves to die. On the petioles and vines, there are narrow brown depressions. The lesions spread and the vines die. If the handle is affected, the young fruit is dark and dark, gradually shrinking to death. Onset of ripe fruit, the disease department began as a water-stained ring, followed by a cratered round spot, on which many rings arranged in small spots, the disease covered with a pink viscous conidia. The young fruit was deformed after infection, and the lesion was contiguous when severe and the watermelon rotted.
Second, prevention and control measures
1. Use resistant varieties and do a good job in seed treatment. The selection of resistant varieties is the key to prevention of anthrax, and different varieties of watermelon have different resistance to anthrax. Practice has proved: Qingfa No.8, Humidity-proof 8802, Huami No.8, early disease-resistant coronary disease, Qingnong No.5, Huami No.10, Zhengkang No.7, Extra-large Zhengkang No.3, Qingfa No.12, and Lubao Golden Flower King. Other varieties have a strong ability to resist moisture and anthrax. Based on the selection of disease-resistant varieties, seed treatment before sowing is also an effective method to prevent anthrax. Can be soaked in 0.1% potassium permanganate solution for 5 to 6 hours, or soaked with agricultural streptomycin 100 times for 10 minutes, after soaking seeds rinse with water 3 to 4 times after sowing germination or live, the effect is good.
2. Rational rotation, scientific fertilization, and sorghum planting. Rotation time is 3 to 4 years in paddy fields and 5 to 6 years in dry lands. More decomposed organic fertilizer and phosphorus and potassium fertilizers, less nitrogen fertilizer, can increase the disease resistance of plants. In the cultivation, the deep ditch sorghum film covering planting is adopted to reduce the groundwater level and the relative humidity of the soil, creating an environment conducive to the growth of the watermelon plant and a condition unfavorable to the propagation of the pathogen.
3. Strengthen field management. Do a good job of pruning, squeezing, and hiccups to maintain a good ventilation and light environment in the field, and no flood irrigation.
4. Chemical control. Spraying medicine at the early stage of the disease can achieve better control effect. 70% thiophanate-methyl 600x solution, 15% pyrethroid 1000x solution, or 20% carbendazim 3000x solution, or 60% chlorothalonil 500x solution, or 80% anthrax oxime 800x solution can be used. Or 70% of the mango zinc 500 times. Sprayed once every 7 days, even sprayed 3 to 4 times, alternating use of drugs, the control effect is better.
Author unit: Vegetable Station of Malipo County Agriculture Bureau, Yunnan Province
First, the incidence of symptoms of watermelon anthracnose from seedlings to mature, in the leaves, vines, fruits can occur. When the seedlings were onset, the near-surface vines turned dark brown and collapsed. When the leaves are damaged, they begin with a small, yellow, water-stained, round spot that later expands to become brown. There is a purple-black circle around the lesion, on which a small black spot or pink sticky material grows. The lesion gradually enlarges, connects each other into pieces, and crushes when dried, causing the leaves to die. On the petioles and vines, there are narrow brown depressions. The lesions spread and the vines die. If the handle is affected, the young fruit is dark and dark, gradually shrinking to death. Onset of ripe fruit, the disease department began as a water-stained ring, followed by a cratered round spot, on which many rings arranged in small spots, the disease covered with a pink viscous conidia. The young fruit was deformed after infection, and the lesion was contiguous when severe and the watermelon rotted.
Second, prevention and control measures
1. Use resistant varieties and do a good job in seed treatment. The selection of resistant varieties is the key to prevention of anthrax, and different varieties of watermelon have different resistance to anthrax. Practice has proved: Qingfa No.8, Humidity-proof 8802, Huami No.8, early disease-resistant coronary disease, Qingnong No.5, Huami No.10, Zhengkang No.7, Extra-large Zhengkang No.3, Qingfa No.12, and Lubao Golden Flower King. Other varieties have a strong ability to resist moisture and anthrax. Based on the selection of disease-resistant varieties, seed treatment before sowing is also an effective method to prevent anthrax. Can be soaked in 0.1% potassium permanganate solution for 5 to 6 hours, or soaked with agricultural streptomycin 100 times for 10 minutes, after soaking seeds rinse with water 3 to 4 times after sowing germination or live, the effect is good.
2. Rational rotation, scientific fertilization, and sorghum planting. Rotation time is 3 to 4 years in paddy fields and 5 to 6 years in dry lands. More decomposed organic fertilizer and phosphorus and potassium fertilizers, less nitrogen fertilizer, can increase the disease resistance of plants. In the cultivation, the deep ditch sorghum film covering planting is adopted to reduce the groundwater level and the relative humidity of the soil, creating an environment conducive to the growth of the watermelon plant and a condition unfavorable to the propagation of the pathogen.
3. Strengthen field management. Do a good job of pruning, squeezing, and hiccups to maintain a good ventilation and light environment in the field, and no flood irrigation.
4. Chemical control. Spraying medicine at the early stage of the disease can achieve better control effect. 70% thiophanate-methyl 600x solution, 15% pyrethroid 1000x solution, or 20% carbendazim 3000x solution, or 60% chlorothalonil 500x solution, or 80% anthrax oxime 800x solution can be used. Or 70% of the mango zinc 500 times. Sprayed once every 7 days, even sprayed 3 to 4 times, alternating use of drugs, the control effect is better.
Author unit: Vegetable Station of Malipo County Agriculture Bureau, Yunnan Province