How to Treat Grape Leaf Diseases? A Detailed Guide to Prevention and Control Methods

During the process of cultivating grapes, some diseases will appear. So, how do you treat grape leaf diseases?

1. How to treat grape leaf diseases?

For different leaf diseases, the treatment methods are different. For example, for grape leaf spot disease, in the early stage of onset, spray a 1500-fold dilution of 50% soluble powder of Junxianling, or a 1:0.7:200 Bordeaux mixture, or a 400-500-fold dilution of 30% basic copper sulfate suspension, or a 500-600-fold dilution of 70% mancozeb wettable powder. Spray once every 10-15 days, for 3-4 consecutive treatments.

1. Black pox

In the early stage of growth of young tender grape leaves, small reddish-brown or dark brown spots the size of needle tips often appear on the leaf surface. These spots have a yellow halo around them and gradually expand, becoming round lesions. The center of the lesion is grayish-white and slightly sunken, with a purple halo around it, and in the later stage the leaves develop holes.

This disease mainly affects the veins of grape leaves, and the leaf shape shrinks and curls, but it only affects young tender leaves; old leaves almost never develop the disease.

2. Anthracnose

Anthracnose is a disease caused by bacterial infection. When it develops, oval lesions appear on the veins and petioles of grapes. The lesions are dark brown, and faint crimson masses of conidia can be seen on the surface. If these symptoms appear, pay attention; it is best to clean up the plant to prevent the grape from spreading the infection to healthy plants during pollination.

3. Gray mold

This disease often occurs before grapes bloom, and the affected part is the leaves. When it develops, large irregular reddish-brown necrotic lesions appear on grape leaves, and the lesions mostly occur at the edges of the veins.

4. White rot

White rot mainly occurs after grapes have set fruit. After onset, the leaf margins and wounded parts of grape leaves show relatively large oval light brown lesions, and there are concentric rings.

5. Downy mildew

In the early stage of downy mildew, the leaves have a transparent, water-soaked, irregular lesion. If you pick the leaf and hold it toward the sunlight, it feels as if you are seeing through it. A few days after onset, the affected area turns yellow, with an irregular shape and unclear edges, and a white young fluffy frost-like mold layer grows on the back of the lesion. In the later stage, the lesion gradually expands to more than 1 cm, and the color of the lesion turns reddish-brown, appearing scorched as if burned. If several spots connect together, the entire leaf will dry up and fall off.