MySheen

How to control sweet potato stem nematode disease by browning halo spot on root epidermis

Published: 2024-11-05 Author: mysheen
Last Updated: 2024/11/05, How to control sweet potato stem nematode disease by browning halo spot on root epidermis

Sweet potato stem nematode disease mainly damages sweet potato roots, stem vines and seedlings. The root of the seedling was damaged, the epidermis was brown, and the seedling was stunted, short and yellowing. The stem symptoms are mostly in the pith of sweet potato stem, which is white at first, and then turns brown and rotten. The symptoms of root tuber can be divided into bran heart type, bran skin type and mixed type.

Sweet potato stem nematode disease

The common symptom of sweet potato tuber nematode disease is bran heart type. The nematodes in the infected stem vine invade the potato tuber downwards. The appearance of the diseased potato is the same as that of the healthy potato, but the inside of the tuber becomes brown and white dry rot. The eggs, larvae and adults of sweet potato stem nematode can survive the winter on the potato block at the same time, and the larvae and adults can also survive the winter in soil and fertilizer. The pathogen can invade directly through the skin or wound of sweet potato. The disease is mainly spread by seed potatoes and seedlings, as well as by Rain Water and farm tools for a short distance. The pathogen can lay eggs, hatch and grow when the pathogen is more than 7 ℃. The optimum temperature is 25-30 ℃, and the highest is 35 ℃. Moist and loose sandy soil is beneficial to nematode activity, while extremely wet and dry soil is not suitable for nematode activity.

Prevention and control methods:

Rotation: in seriously diseased areas or seriously diseased areas, rotation should be carried out. Sweet potato rotation in sorghum, corn and cotton for three years can basically control the occurrence and harm of sweet potato stem nematode disease.

Soak sweet potato seedlings with 50% phoxim EC or 40% methyl isophos emulsion for 10 minutes.

Chemical treatment of soil: 5% aldicarb granules 2-3 kg per mu, sweet potato seedlings transplanting, applied into the hole, the drug valid in the field for 50-60 days, can effectively control stem nematode disease and other insect pests. You can also use 3% isosalidophos granules of 3-4 kg per mu, mix the right amount of soil, and apply it into the hole.

 
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