Scientific Control of Potato late Blight

Potatoes, Solanaceae, annual herbs, also known as eggs, potatoes, potatoes and so on. The earliest artificial cultivation of potatoes can be traced back to southern Peru from about 8000 to 5000 BC. Native to Peru and Chile in the Andes of South America. Lake Titicaca, 3800 meters above the Andes, is probably the first place where potatoes were cultivated. About 7,000 years ago, an Indian tribe migrated from the east to the cold Andes, camped near Lake Titicaca, hunted and gathered for a living, and was the first to discover and eat wild potatoes.

Potatoes like cold and cool, and they are crops that like low temperatures. The formation and growth of underground potato lumps need a loose, ventilated, cool and moist soil environment. Temperature requirements: the suitable temperature for tuber growth is 16 ℃ ~ 18 ℃, when the local temperature is higher than 25 ℃, the tuber stops growing, and the suitable temperature for stem and leaf growth is 15 ℃ ~ 25 ℃, and stops growing when it exceeds 39 ℃.

Potatoes are rich in dietary fiber, which helps to promote gastrointestinal peristalsis and dredge the intestines.

In addition, potato tubers contain carotene and ascorbic acid that are not found in cereal grains. From a nutritional point of view, it has more advantages than rice and flour, can provide a lot of heat energy to the human body, and can be called "perfect food". People only rely on potatoes and whole milk to maintain life and health. Because the nutritional composition of potatoes is very comprehensive, the nutritional structure is also more reasonable, but the amount of protein, calcium and vitamin An is slightly lower, and this happens to be supplemented with whole milk. Potato tubers are rich in moisture, low in fat and low in calories per unit volume. They contain about 4 times as much vitamin C as apples, 4 times as many B vitamins as apples, and several times to dozens of times as many minerals as apples. Potatoes are blood pressure-lowering food. More or less nutrients in the diet can cause disease. By the same token, if you adjust your diet, you can "eat" the corresponding diseases.

Potatoes have anti-aging effects. It is rich in B vitamins such as vitamin B1, B2, B6 and pantothenic acid, as well as a large amount of high-quality cellulose, as well as trace elements, amino acids, protein, fat and high-quality starch.

Scientific Control of Potato late Blight

Potato late blight has occurred in varying degrees over the years, seriously affecting the improvement of potato quality, yield and economic benefits. therefore, it is very important to control potato late blight. Potato late blight, also known as blight, is a common and serious epidemic disease. All potato planting areas have occurred, non-resistant varieties in the epidemic of late blight, field yield loss of up to 20%-50%, light cellar loss of 5%-10%, heavy more than 30%. Late blight can not only harm potatoes, but also cause harm to tomatoes, peppers, eggplant and so on.

Disease symptoms of potato late blight

Potato leaves, petioles, stems and tubers can be infected. In the early stage of leaf disease, dark green water stains appeared on the leaf tip or leaf edge. When the weather was wet, the disease spot expanded rapidly, and a white and sparse mildew wheel appeared on the edge, especially on the back of the leaf. In severe cases, the disease spot extends to the main vein and petiole, causing the leaves to wilt and droop. When the climate is dry, the disease spot dries up and turns brown. Stem damage, initially showing slightly sunken stripes, when the climate is humid, the surface also produces white mold. The tuber was damaged to form a light brown or grayish purple irregular spot, slightly sunken, and the lower layer of potato turned brown. When the soil is dry, the disease is hard to shrink, and white mildew can also grow when it is wet.

Potato late blight mainly damages leaves, stems and tubers. After the disease, the area and number of leaf disease spots increased rapidly, which caused the early death of potatoes in the whole field, and caused tuber rot, which seriously affected the yield. This year, autumn potatoes in our county have a large planting area and generally grow well. Combined with the fact that Shizong has entered autumn with continuous rain, low temperature and humidity, and large temperature difference between day and night, potato late blight is easy to occur.

Control methods of potato late blight

1. Breeding and popularizing resistant varieties: selecting resistant varieties is the most economical and effective way to control late blight. The resistance of different potato varieties to late blight is very different, because potato late blight is easy to mutate, and vertical resistant varieties are easy to lose their disease resistance after several years of culture. therefore, disease-resistant varieties with multi-genes or horizontal resistance should be selected.

2. Establish the disease-free seed field and eliminate the primary infection source: because the disease-free seed potato is the only primary infection source, the establishment of disease-free seed land can greatly reduce the initial infection source and effectively prevent the occurrence of late blight. More stringent control measures should be taken to keep the land. Where there are conditions, the planting land should be more than 2.5km away from the field, so as to reduce the chance of pathogen transmission. In addition, selecting disease-free seed potatoes can also reduce the source of initial infection, while soaking seeds with chemicals can kill internal germs of seed potatoes, delay the occurrence of late blight for 20 days, reduce the disease index by about 50%, and use 25% metalaxyl 100g, plus a small amount of water immersion or spraying.

3. Strengthen field management: 1): soil preparation, high terrain selection, good drainage and planting, take measures such as soil cultivation, tobacco root removal, ditch drainage and other measures to increase the application of potash fertilizer and improve disease resistance. 2): selecting seed potatoes before sowing and eliminating bacterial tubers can reduce the number of diseased plants in the center of the field. Soil cultivation in the later stage of potato growth can reduce the chance of zoosporangium infecting potato pieces. In the epidemic year, if the seedlings were stopped early and harvested 2 weeks later, the contact between potato pieces and diseased plants could be avoided and the carrying rate of potato could be reduced.

4. Chemical control: at the initial stage of the occurrence of late blight, the diseased plants should be found and removed in time, and chemical agents should be sprayed on the plants within the range of 30mur50 meters around the central diseased plants. after that, they should be sprayed once every 7-10 days, generally 2-3 times, according to the situation. it has a good control effect. Drugs can choose 58% metalaxyl manganese zinc, 64% antiseptic alum, Dasheng MUE 45, 72% DuPont dew, 69% Anke manganese zinc, and so on. In order to reduce the emergence of pesticide resistance, it is best to use a variety of agents alternately.

In a word, potato late blight is a destructive disease with serious harm. The prevention and control of potato late blight in our county should be based on the principle of "prevention first, comprehensive control". It is necessary to take agricultural control as the basis, chemical control as the auxiliary, and the comprehensive use of a variety of control measures in order to achieve good control results.