How to control potato late blight and lose its value

Potato infected with late blight is accumulated and transmitted from generation to generation through tuber asexual reproduction, which leads to the deterioration of tuber species, the continuous decline of yield, the loss of value, and can not be reproduced. There are two ways to control potato late blight:

Potato late blight

(1) precautionary measures

The main results are as follows: (1) selection of disease-resistant varieties: potato varieties with disease resistance include starch processing type, virus-free Xiazhai-65, vegetable varieties with high resistance, Qingshu 9, Qingshu 2, etc. Different producing areas can be selected according to local conditions.

(2) selecting disease-free seed potato to reduce the source of primary infection. In the process of income cellar in autumn, cellar inspection in winter, cellar exit, slicing, vernalization and so on, diseased potatoes should be strictly removed every time, smooth-skinned, about 100 grams of mature seed potatoes should be selected, and disease-free seed potatoes should be purchased if possible.

(3) seed dressing: 70% of dimethazone wettable powder, the dosage is 0.1% of the seed, pay attention to mix with the seed.

(4) Agricultural prevention and control

① rotation: to prevent continuous cropping, rotation should be carried out with non-Solanaceae crops for more than 3 years.

② cultivate disease-free and strong seedlings: apply sufficient base fertilizer, implement formula fertilization, avoid partial application of nitrogen fertilizer, and increase the application of phosphorus and potassium fertilizer. Weeds should be pulled out in time after finishing the seedling.

Reasonable close planting of ③: planting 3900 plants per mu can improve the ventilation and light transmission in the field, reduce the humidity in the field and reduce the occurrence of diseases.

(2) treatment measures: if the potato enters the early flowering stage, if it encounters continuous rain, it should be detected early by frequent inspection, and at the initial stage of the disease, diseased leaves, fruits and diseased plants should be removed in time. When the disease is more serious, remove the central diseased plants, diseased leaves, etc., timely use 58% metalaxyl wettable powder 400 times or 64% poisonous alum wettable powder 500 times, 5 music once in 7 days, 2-3 times in succession.