Prevention and control methods of yam diseases and insect pests with more precipitation this summer

The cultivation of Chinese yam is more common, the price is more than 4 yuan / kg in recent years, the benefit is good, the area is expanded, coupled with more rainfall this summer, diseases and insect pests are more serious. The main disease and pest control methods of Chinese yam are introduced as follows:

Chinese yam management

I. Agricultural prevention and control

1. Use disease-resistant varieties: effectively control diseases and insect pests of yam. During cultivation. The varieties should be rotated every 2 ~ 3 years, and attention should be paid to the purification and rejuvenation of the varieties of yam.

2. Rotation should be carried out to reduce or avoid the harm of Chinese yam by stem rot and root-knot nematode. Rotation with uninfected crops such as peanut, corn, radish and watermelon at least once every 3 years; rotation of yam should be done at least once a year in the old areas where yam is cultivated all the year round; and flood-drought rotation should be carried out in plots with irrigation conditions.

3. Fine soil preparation will directly eliminate the pathogens that overwintered in the soil. Selecting high dry, low humidity, fertile and loose sandy loam for soil preparation in autumn can also turn the diseased remains on the surface into the soil and accelerate the decomposition and decay of the diseased remains. After freezing in winter and drying in spring, some pathogens lose their vitality.

4. Rational fertilization and irrigation. Chinese yam likes fertilizer, and rotten organic fertilizer must be applied when preparing the soil. Generally, the application of phosphorus and potassium fertilizer is beneficial to form the mechanical tissue of Chinese yam and enhance the disease resistance. Excessive application of nitrogen fertilizer is easy to cause excessive growth of yam plant, tender stem and leaf tissue, and easy to get anthracnose. Watering is not dry do not water, watering with clean water, must be watered thoroughly, there can be no stagnant water in the field, the rainy season should be timely drainage, so as not to cause root rot of yam.

II. Chemical control

1. Chinese yam anthracnose, gray spot, brown spot, etc., harm stems and leaves, resulting in stem withering and falling leaves. Control method: soak the seed potato with 1 ∶ 1 ∶ 150pod solution for 10 minutes. Spray the first time (50% carbendazim 600 times liquid) when the seedlings are full, and spray the second time 10 days later. From July to August, the disease occurred, using 40 million 60 milliliters of 25% imipramine EC per mu of yam, or 75% diazepam of 15 grams per mu, and 20ml of water. Spray 2 times and 4 times according to the severity of the disease, and spray alternately. Every time the interval is 8 to 10 days, the spray solution should be replenished after the rain.

2. Short body nematode disease caused Chinese yam plant dwarfing, when it was serious, the whole plant withered, tuber was damaged, tubercle appeared, and the yield and quality were affected. Prevention and control methods: before sowing, mix the soil with chemicals, 5 kg of methophos granules per mu mixed with 100 kg of moist fine soil, ditch evenly spread on both sides of the yam, or combined with soil preparation. Spread it evenly and bury it 25cm to 30cm.

3. Grubs bite on tubers. Treatment of soil, control, 250-300ml 50% phoxim per mu, add 25 kg of fine soil to mix well, sprinkle into the ridge, immediately cut into the soil layer of 20cm, and then sow yam species.