What pesticide is effective for controlling walnut black rot?

For walnut black rot, use Bordeaux mixture at a 1:1-2:200 formula, 35% basic copper sulfate suspension concentrate at 400-500 times dilution, 35% basic copper sulfate (Lüdebao fungicide) at 300-400 times dilution, DT fungicide at 3000-4000 times dilution, or agricultural streptomycin at 100-120; spray the first time in mid-month, and thereafter spray once about every 15 days, for a total of 2-3 sprays, which gives a relatively good control effect.

1. What symptoms does walnut black rot have?

Walnut black rot mainly damages the fruit. When the fruit is infected in the early stage, small brown spots appear on the green husk and gradually expand and turn dark brown, and the flesh rots. The pathogen can infect the kernel portion, and finally the entire fruit rots, shrivels, and drops off. When the fruit is infected in the later stage, the lesions expand more slowly; because the endocarp has hardened, although the flesh rots, it does not rot as far as the kernel and the fruit does not drop easily, so the loss is relatively small. It can also infect young branches, young leaves, and flowers. The peak incidence period of this disease is during the rainy season.

2. How is walnut black rot prevented?

1. Selecting and breeding resistant varieties is one of the important ways to control this disease; disease resistance should be taken as one of the important indicators in walnut selection.

2. Strengthen cultivation management, and cultivate strong seedlings and strong trees; prune reasonably to reduce microclimate humidity; promptly remove diseased leaves, diseased fruits, and diseased branches to reduce field pathogens. In the early stage of the disease, spray with 50% thiophanate wettable powder or 70% thiophanate-methyl wettable powder at 1000-1500 times dilution.

Summary: The above content is the introduction to walnut black rot compiled by the editors of Tuliu.com, and we hope it can help farmers in need.