Causes and Prevention of Potato degradation

(1) the causes of potato degradation

Potatoes are planted in spring in hot summer areas in the south. After a year or several years, the yield gradually decreases, or even no harvest at all. This phenomenon is called potato degradation. The direct external cause of potato degradation is virus damage. Mosaic virus, mosaic virus, common mosaic virus and hammer tuber virus are common in southern China. These viruses infect plants and cause degradation through vectors such as mechanical friction, aphids, leafhoppers or soil nematodes. High temperature is the indirect external cause of potato degradation. When potato is cultivated at high temperature, its growth potential is weak and its disease tolerance is decreased. Moreover, high temperature is beneficial to the reproduction, infection and spread of the virus in the plant, which aggravates the harm of the virus and aggravates the degradation.

The internal cause of potato degradation is the virus resistance of potato varieties. The disease of the varieties with strong disease resistance is lighter, the degradation is not serious, and the disease is serious and the degradation is more serious in the varieties with weak disease resistance. Therefore, varieties with strong disease resistance should be selected.

(2) measures to prevent the degradation of potatoes

1. Select varieties with strong disease resistance. The selection of varieties with strong disease resistance is an effective measure to prevent degradation. At the same time, attention should be paid to improving the breeding system and system of improved varieties, establishing seed retention bases in high mountains, and combining the selection of improved varieties with virus prevention and protection, so as to maintain the productivity of improved varieties and prolong their useful life.

2. Autumn sowing and late sowing. Autumn sowing and late sowing make the tubers grow in a cool climate, enhance disease resistance, and are not conducive to virus reproduction and infection, and can reduce degradation.

3. Removal of virus: (1) selection of superior plants to expand propagation. In the fields where the virus infection is not serious, a robust and excellent single plant is selected to propagate and leave seeds, and the diseased plants are eliminated. (2) using real potato as seed. Potato viruses rarely invade pollen, eggs and seed embryos, so through sexual reproduction, viruses accumulated in asexual generations can be eliminated to produce virus-free seeds, seedlings and potatoes to prevent degradation. (3) non-toxic seed potato was cultured at stem tip. The meristem of stem tip is basically virus-free, so virus-free plants and potato blocks can be obtained by stem tip tissue culture, and then this non-toxic original potato block can be used as seed in production, which can eliminate most viruses and prevent degradation. (4) improve cultivation techniques and storage conditions. Adopting suitable cultivation measures such as sandy loam planting, high fertilizer and water, reasonable close planting, strengthening field management, controlling aphids and timely early harvest can promote plant robust growth, enhance anti-degradation ability, reduce field virus and prevent degradation. During storage, it is necessary to avoid the effects of high temperature or low temperature freezing injury, water loss and shrinkage, premature germination, loss of nutrients, diseases and insect pests, so as to prevent seed potato from aging, reduce vitality and cause degradation.