Potato diseases and their control

Potato is a widely planted crop in China, with high yield, rich nutrition and good taste, which is deeply loved by the public. Potatoes are cool-loving crops, and can be sown when the ground temperature is lower than 25℃. In autumn, varieties with shorter growth period are generally selected, and 20-30 grams of whole potato is used as seed potato, which can improve the survival rate. The field management of autumn potato mainly includes drought resistance and drainage, seedling condition inspection, weeding and fertilization. Pests and diseases are more active in autumn, so it is necessary to strengthen the management of disease prevention and pest control. The following are common diseases and insect pests of autumn potato and their control methods, which can be used for reference by growers.

Ring rot

Ring rot is mostly caused by virus-bearing seed potatoes, so it may occur in the whole autumn potato cultivation process. At seedling stage, ring rot will inhibit the growth of seedlings, and the leaves of seedlings will shrink, which will lead to the death of seedlings in severe cases. When flowering, the stems and leaves wilted and died from top to bottom, and the diseased potatoes were found to be milky yellow or brown ring rot when cut open.

Ring rot is harmful to the growth of autumn potatoes, such as large-scale disease will lead to reduced production or no harvest. Therefore, it is necessary to cut off the ring rot from the source, choose disease-free potatoes, and pay attention to disinfection knives when cutting into pieces to avoid cross-infection.

viral disease

Viral disease is an infectious virus. The main symptoms of autumn potato are short plants, slow growth, curly leaves and dark colors.

The prevention and treatment of virus diseases mainly starts from the following three aspects: selecting virus-resistant potato varieties and using whole potatoes or seedlings as seed potatoes; (2) Prevention and control of aphids. Aphids can spread viruses among potatoes, and 40% omethoate 1000 times can be sprayed; (3) At the initial stage of the disease, 300 times of Kangdufeng (0.5% mushroom proteoglycan aqueous solution) or 500 times of 20% virus A wettable powder can be sprayed for chemical control.

Potato ladybug/ladybug

Ladybugs do great harm to potatoes. They often feed on mesophyll and fruit, and the damaged potato leaves will dry up and turn brown. Fruit is often broken when chewed, thick and bitter, and can't be eaten.

Spraying 80% trichlorfon wettable powder or 80% dichlorvos emulsifiable concentrate 1000 times, 2.5% dichlorvos emulsifiable concentrate and 10% cypermethrin emulsifiable concentrate 1 times every 10 day can kill ladybugs.

Midges and flies

White grub is an underground pest, which sucks newly sown seeds and seedlings and harms the growth of potatoes.

Grubs can be controlled by comprehensive methods such as physical control and chemical control. Physical control, such as not applying immature fertilizer, using black light to trap and kill; Chemical control mainly uses 50% phoxim, water and seeds, and the ratio is 1: 50: 600. After seed dressing, the larvae can be killed by aerial sowing. Or use 80% trichlorfon wettable powder and fine soil 15 kg ~ 20 kg to make medicinal soil and spread it in sowing ditch for control.