What fungicides work well to control yellow spot disease in fruit trees

When yellow spot disease infects fruit trees, it causes large numbers of leaves to drop, and the fruit develops mottled patches and stores poorly.What fungicides should be used for yellow spot disease in fruit trees?

1. What fungicides to use for yellow spot disease in fruit trees

For yellow spot disease in fruit trees, you can use fungicides such as carbendazim, mancozeb, Bordeaux mixture, trifloxystrobin · tebuconazole, and hymexazol, applied alone or in combination according to the severity of the disease.

2. Applying fungicides for yellow spot disease in fruit trees

1. For bearing trees, spray for the first time after 2/3 of the flowers have fallen; for non-bearing trees, spray for the first time after the spring shoot leaves have unfolded, then spray 1-2 more times at an interval of 20 days. Choose 80% carbendazim wettable powder at 800-1000 times dilution, or 80% mancozeb wettable powder at 500 times dilution, or 0.5% equal-amount Bordeaux mixture.

2. After removing the diseased leaves, apply trifloxystrobin · tebuconazole mixed with hymexazol.

3. The harm caused by yellow spot disease

On a single leaf of an affected plant, several dozen or even over a hundred spots can appear, blocking photosynthesis, weakening the tree's vigor, causing heavy leaf drop, and having a certain impact on yield. After twigs are affected, they become stunted and stop growing, which affects the expansion of the canopy; after fruit is affected, large numbers of oily stain marks and blemishes appear, affecting the fruit's marketability.

Yellow spot disease has 4 types: the lipid-spot yellow spot type, the brown small round spot type, the mixed type (that is, on 1 leaf both lipid-spot yellow spot disease and brown small round spot type lesions occur), and the symptoms on fruit.

This disease is caused by infection by Mycosphaerella citri, a fungus of the genus Mycosphaerella in the subphylum Ascomycotina.

The pathogen overwinters as mycelium in diseased leaves and fallen leaves. The following spring, the ascocarps release ascospores, which spread by wind, rain and other means. The optimal temperature for the growth of this pathogen is around 25°C; May-June, being warm with surplus moisture, is most favorable for the formation, release and spread of ascospores and the damage they cause. Extensive cultivation management, weakened tree vigor, and incomplete orchard sanitation will aggravate the disease.

While using chemical control, we must strengthen cultivation management, and by applying fertilizer, enhance tree vigor and improve the disease resistance of the fruit trees.