How to Control Potato soft Rot during Storage

Potato soft rot, which harms potato tubers during storage, is a bacterial disease. It occurs every year, and the yield is reduced by 3% to 5% in general years, which is often co-infected with potato dry rot, resulting in greater losses. The harmful symptoms and control methods of potato soft rot are as follows:

Soft rot of potato

First, harmful symptoms

Soft rot usually occurs on potato tubers in the late growth period before harvest and during storage. Infected tubers, stomata slightly sunken, brown or brown, surrounded by water immersion. Under the dry condition, the lesion hardens and dries, and the necrotic tissue is sunken. When it comes to decay, the soft rot tissue is moist and creamy or brown, with soft particles. There is a clear boundary between infected tissue and healthy tissue, with brown or black pigment at the edge of the spot. There is no smell in the early stage of decay, and there are odors, mucus and sticky substances after secondary infection.

II. Ways of transmission

Potato soft rot is a bacterial disease. the common pathogens of soft rot are carrot soft rot and black shank, which belong to anaerobic bacteria and are easy to spread in water. The infection cycle of soft rot is similar to that of black shank. Enter from other lesions to form secondary infection and compound infection. The previously infected potato mother plant infects the offspring tuber through the stolon. Warmth, high humidity and hypoxia are beneficial to the soft rot of potato tubers. When the ground temperature is 20-25 ℃ or above 25 ℃, potato tubers will be highly susceptible to disease. The anaerobic environment caused by poor ventilation, stagnant water in the field and water film on the potato stem after washing is conducive to the occurrence and development of the disease. The application of more nitrogen fertilizer can also improve the susceptibility.

III. Prevention and control methods

1. Strengthen the field management, pay attention to ventilation and light transmission, and reduce the humidity in the field.

2. The diseased potato plants should be pulled out in time and disinfected with lime to reduce the sources of primary and secondary infection.

3. Avoid flooding.

4. Spray 50% chlorothalonil wettable powder 500 times or 12% green copper EC 600 times, 47% Ruinong wettable powder 500 times, 14% ammonia copper water 300 times.