Occurrence and Control of Sweet Potato Black Spot

Sweet potato black shank, also known as sweet potato black shank, has caused the disease to occur more commonly in some places due to unscientific introduction, continuous cropping, and improper cultivation measures, which has seriously affected the income of the potato farmers. Sweet potato black shank disease is mainly immersed in the root cortex, and at the early stage of disease, the epidermis of the potato chips forms pale brown spots, and then gradually expands to form irregular spots with large grayish black and black irregularities. Although lesions are not deep inside the tissues, the appearance quality of sweet potatoes is reduced due to the continuous expansion of epidermal lesions, which seriously affects the commercial value of sweet potatoes. Sweet potato black shank disease is mainly spread by seed potato, potato turning and soil, and occurs seriously in low-lying land, clay land, and concentrated precipitation years. The source of the disease can survive in the soil for more than 2-3 years, and it can also pass the seed potato seed. The seedlings spread.
Sweet potato black shank disease prevention and control is mainly based on comprehensive prevention and treatment, and disease-free seed potatoes should be selected to cultivate disease-free seedlings. After the harvest, diseased potato and residual stems and leaves were removed from the area and three or more rotations were implemented. Use sorghum or ridge planting. Drain the water immediately after the rain to prevent moisture from staying. Increase the maturity of organic fertilizers to increase soil permeability and reduce the survival rate of pathogens.