Integrated control of pollution-free diseases, insect pests and weeds in sweet potato

(1) selection of seed potatoes to select disease-free, insect-free and injured tubers as seed potatoes

(2) Chemical treatment of seed potato (slightly)

(3) Potato cellar management put potato seeds into aseptic cellar for storage, it is best to use a new cellar. If you use the old cellar, first dig off the cellar wall, then fumigate with sulfur 15g / m2, store the potato pieces within three days, use the fire to pass through the cellar, raise the temperature to 3739 ℃, keep it 48 hours, open the door, the pit temperature drops and maintain 11,13 ℃.

(4) nursery bed management (1) raise seedlings with new bed soil, disease-free and insect-free manure. (2) before controlling the humidity of seed potato treatment, the seedling bed temperature was controlled above 25 ℃. After seed potato treatment, the disease, injury and frozen potato were further removed. The temperature of seed potato was controlled at 3034 ℃ in the first week, and then the bed temperature was controlled at about 25 ℃. (3) during the period of pulling out diseased seedlings and raising seedlings, the nursery bed was checked every 5-7 days, and it was found that diseased plants such as virus diseases were pulled out together with seed potatoes. (4) the high-cut seedlings should be cut 3cm above the ground, once for spring potatoes and twice for summer potatoes, that is, the seedlings should be cut from the seedbed, inserted in the open nursery, and then inserted into the field with the second high-cut seedlings in the open nursery. Never pull out the seedlings (to prevent black spot). Use the high-cut branches on the stem as potato seedlings (to prevent stem nematode disease).

(5) treatment of potato seedlings (1) the diseased seedlings should be strictly removed before planting and the diseased part should be cut off. (2) according to the type of disease, one of the methods can be selected: ① soaked the stem base 6 × 10 cm deep 10min with 50% carbendazim wettable powder 1000 × 2000 times or 50% topazin wettable powder 500 times, followed by cutting to control smut. ② soaked the high-cut potato seedlings in 45 ℃ warm water 5min and then immediately soaked 4min in 50 ℃ warm water. Rinse them with cold water to prevent stem nematode disease. ③ cuttings of 667 square meters of soil were evenly mixed with 50% phoxim 0.25 kg and fine soil 20 kg to dry. When transplanting seedlings, the poisonous soil was first applied into the planting hole, and then the seedlings were planted after the drug solution was infiltrated to control stem nematode disease.