What causes yellow spots on apple leaves?

1. Lack of potassium fertilizer

The appearance of yellow spots on the leaves of apple trees may be due to a lack of potassium fertilizer, which will not only cause yellow spots, but also cause the edges of the leaves to dry up, resulting in poor growth of the apple tree. You can analyze the soil composition to determine whether the soil lacks potassium, apply fertilizers rich in potassium to the roots, and spray the leaves to ensure that the plants can absorb enough nutrients.

2. Infections and diseases

The appearance of yellow spots on the leaves may be due to leaf spot disease, which is more likely to occur in an environment with heavy rain and high temperatures. When the disease first occurs, small spots will appear on the leaf surface, which will then gradually expand and eventually connect together, causing the entire leaf to fall off. After discovering the disease, the diseased leaves must be removed in time and then sprayed with pesticides. You can use 400-600 times diluted 70% mancozeb wettable powder, or 700 times diluted 70% antasen WP, both of which have good effects.

3. Pesticide is too concentrated

Apple trees need to be sprayed with pesticides appropriately during their growth process. If the concentration of pesticides used is too high, yellow spots will appear on the leaves, eventually causing the leaves to fall off. You can spray slow-release agents in time and add appropriate fertilizers to restore the growth of the tree.