Yam belongs to the diospyrifos family, has a high nutritional value, can not only be eaten as a vegetable, but also as a medicinal health product, the economic benefits of planting are high. However, with the continuous expansion of the planting area in recent years, the occurrence of pests and diseases has become more frequent and serious.
1. Yam brown spot disease
This disease mainly affects the leaves of plants, and is most seriously affected during the rainy season. At the beginning of the disease, yellow and yellow-white spots will appear on the leaves of the plant, and in the later stages, the color of the leaves will gradually change to light brown, and when the disease is serious, the entire leaves will die. In the early stages of the disease, we can spray 50% dentate 600-800 times liquid every 7-10 days, or water with 70% methyl tolbucin 1000-1500 times liquid. If the condition is serious, we can also use 2.5% enemy kill 1000-2000 times liquid for prevention and treatment.
2. Yam anthrax
The disease mainly harms the leaves and stems of the plant, and after the leaves are infected, there will be two types: acute and chronic. For acute anthrax, it is very common, the incidence is fast, the degree of harm is heavy, the spots are relatively small, most of the irregular brown spots appear at the junction of petioles and leaves, petioles and stems, and spots are uncommon on the leaf surface, and after a few days, the leaves will fall off. For chronic anthrax, the onset is slower, in the early stage of the disease, there will be brown irregular spots on the leaves, and then gradually expanded, becoming black-brown round, oval, irregular-shaped large spots, the middle of the spots appear gray, grayish-white, accompanied by irregular concentric chakra, part of the rupture and perforation, resulting in leaf shedding. After the yam stem is damaged, it will produce amorphous, fusiform brown spots, some spots are slightly concave, and the severe spots will expand and connect into pieces, causing the whole plant to die. In the initial stage of the disease, every 7-10 days spray 50% dentist 600-800 times liquid, 70% methyl tolbuzin 1000-1500 times liquid, spray 2-3 times continuously, in addition, we must remove diseased leaves in the field in time to eliminate stagnant water.
3. Short-body nematode disease
This disease will cause the plant to dwarf, when the damage is serious, the whole plant will turn yellow and die; when the tubers are damaged, there will be small tumors of different sizes, affecting the yield and quality of yam. Before sowing seeds, we need to treat the soil with a chemical agent, mix 100 kg of fine soil with 5 kg of phosphorus granules per mu of land, and spread it evenly on both sides of the seed potato after trenching. We can also combine the preparation of the ground and spread evenly, into the soil 25-30 cm can be.
4. Leaf bees
The insect bites the yam leaf, causing a severe loss of the leaf, which in turn affects photosynthesis, eventually leading to lower tuber yield. We can use 2% enemy to kill 3000-3500 times liquid, 90% crystal enemy worm 1000-1500 times liquid, stem and leaf spray control.