Prevention and Control of Potato Shrinkage Mosaic Disease

Sweet potato wrinkle mosaic disease, also known as sweet potato latent virus disease.

(virus English name) Sweet potato latent virus, abbreviated as SPLV.

(host crop) sweet potato, Convolvulaceae, Chenopodiaceae and some Solanaceae crops.

(disease diagnosis) in the seedling stage, the germination number of diseased seed potato was more than that of healthy potato, the leaves of diseased seedlings were wrinkled and small at the initial stage, and the leaf veins were yellowish and transparent, and the leaves often formed light green and thick green flowers and leaves in the later stage. After the diseased seedlings were cut into the field, the leaf edges of diseased plants were notched or irregular, the leaves were significantly wrinkled, the vines of seriously diseased plants were shortened, and the leaves shrunk, wilted and withered. The mildly diseased plants could continue to grow, and the symptoms disappeared when the temperature was more than 30 ℃, and it was difficult to distinguish the new leaves from the healthy plants. when the temperature decreased, the lateral branches and shoots from the top tips and axillary buds of the vines showed the symptoms of mosaic shrinkage again. The diseased plant can still bear potatoes, but the tubers are small and deformed. The pathogen is sweet potato latent virus, which is curved and long rod-shaped, about 700nm long.

Virus-carrying tuber is the main source of disease. The seedlings raised by diseased potatoes are all diseased seedlings, and the diseased seedlings are planted in the field and produce pieces of poisonous potatoes, which can be transmitted over a long distance. When collecting seedlings, it can also be transmitted by contact with the sap of cutting seedlings, and aphids and whitefly in the field do not transmit virus. The symptom of the diseased plant was closely related to the temperature, especially at the temperature of 20-25 ℃, and the occult disease was over 30 ℃. In addition, the symptoms are also related to soil, farming system, planting period and so on.

(control measures) (1) select disease-resistant varieties, such as Xushu 18, Lushu 7 and Beijing 553. (2) it is best to use virus-free potato seedlings. (3) strengthen the seedling bed inspection and find that the diseased seedlings are dug up together with potato pieces. Diseased plants are found in the field, and healthy seedlings are replanted after being pulled out in time. (4) strengthen the management of fertilizer and water and improve the disease resistance of plants. (5) spray 15% virus Bike wettable powder 600 times solution, or 20% virus king wettable powder 500 times solution, or 10% virus king wettable powder 500 times solution, or 83 resistance enhancer 100 times solution in time.