Symptoms and control measures of wean atrophy
Green onions are a common vegetable and are popular among consumers. Therefore, there are many farmers who grow green onions. When planting green onions, the onion shrinkage is a common type of disease, causing serious economic losses to farmers.
Scallion atrophy symptoms
It is a yellow dwarf virus on the onion, a yellow strip virus on the garlic, and a latent virus on the shallot. The newly planted onion seedlings grow well. If there is high temperature and drought in July, a few typical atrophic strains appear in August, and the peak incidence is from mid-September to mid-October. The new leaves born in the early stage of the disease are thin, the leaves are light, the pale yellow spots appear on the heart leaves, the leaves are uneven, spirally twisted, some leaves are twisted to one side, the plants are atrophied, and the onions are more The smaller the length. According to the field observation: the old vegetable field seedlings are planted repeatedly; the "autumn seedlings" before the seedlings are early, the spring is more fleas; the onion is sun-dried and semi-dried; the onion seedlings are thrips, the aphids are heavier; the soil is arid after replanting; July The temperature is high, and the year when the rain is less is heavier.
Welsh onion shrinking disease prevention and control measures
(1) When breeding seedlings, use Zhangqiu big paulownia, Wuyeqi and its first generation hybrids, Luoyang Holly, Tangshan monologue and other resistant varieties;
(2) Before the "autumn", the early seedlings will be raised after the "autumn" and the seedlings will be vigorously promoted.
(3) Use 40% of dimethoate and 80% dichlorvos mixture 1000 times in seedling stage, add a small amount of washing powder or waste soy milk, increase the adhesion ability (the same medicine is used), and control the thrips and aphids;
(4) Before applying the onion, re-apply the base fertilizer, classify the seedlings, use the 1000 times of the syrup to remove the roots, and plant the strong seedlings;
(5) After the resurrection of the planting, the onion ditch is covered with 250 kg/667 m2 or potato bran, and the fresh weeds are 300 kg/667 m2 to moisturize and cool the soil;
(6) During the growing period from August to October, apply 50 kg/667 square meters of special compound fertilizer for scallions, and apply urea twice, 20 kg/667 square meters each time. Topdressing and cultivating, soil cultivation and watering match each other. Promote the growth of onion seedlings;
(7) Spray 2 times before planting onion, once every 7-10 days, spray 3 times of naphthaleneacetic acid amine solution after planting, and add 20 kg of water to prevent disease and strong trees;
(8) If there are still a small number of diseased plants in the onion field, use 0.5% of the anti-pathogenic factor No. 300-400 times or 25% of the anti-virus No. 1 wettable powder 300 times, or 1.5% of the plant disease 400 times. , thoroughly control, to ensure that the green onions grow well.
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