Sweet potato becomes bitter and produces black mildew how to control black spot of sweet potato

Sweet potato black spot is an important disease in sweet potato production, which occurs everywhere. The whole growth period of sweet potato can be damaged by bacteria, mainly the root of sweet potato tuber and the base of seedling stem. At the base of the diseased seedling, the leaves turn yellow and fall off, the underground part turns black and rotten, and the seedling is easy to die, resulting in lack of seedlings and broken ridges. Before and after harvest, the disease occurred most frequently, with brown to black spots, slightly sunken in the center, and black mildew or prickles on it. Diseased potatoes become bitter and cannot be eaten, prevention and control measures:

Black spot of sweet potato

1. Reasonable crop rotation:

Select sweet potato varieties with strong disease resistance and establish disease-free seed land; before seedling cultivation, seed potatoes are soaked in 50% carbendazim wettable powder plus 800-fold solution of new high-fat film for 5 minutes; before transplanting, sweet potato seedlings can be soaked in 500-fold solution of 50% ethyl topiramate and 800-fold solution of new high-fat film for 10 minutes to further sterilize.

Second, strengthen management:

Timely ploughing to preserve soil moisture and reasonable topdressing, spraying 800-fold solution of new high-fat film in order to protect fertilizer effect, spraying Di Guo Zhuangtiling after sweet potato branching period, in order to effectively control the wild growth of branches and leaves in the upper layer of sweet potato surface, accelerate the expansion of underground tubers, enhance the ability of resistance to insect pests and ensure the high yield of sweet potato.

3. Chemical control:

At the initial stage of the disease, targeted agents (such as 50% carbendazim wettable powder and 75% carbendazim 500 times liquid) should be sprayed according to the condition of sweet potato, once every 7-10 days, 3-4 times successively; in order to enhance the efficacy, 800 times liquid of new high-fat film can be sprayed to consolidate the prevention and control effect.