What are the small black spots on grapes
Today, I will explain to netizens what the small black spots on grapes are and share the related experience of grape anthracnose and control methods in flower planting. Here is the detailed content.
Small black spots often appear on grapes after they start to bear fruit, which is caused by the tree being infected with anthracnose, usually occurring on fruits that are about to ripen. The small black spots are symptoms of the pathogen and will gradually spread to the entire surface of the grape. They are more likely to cause diseases in humid and rainy conditions. Enhancing ventilation and strengthening cultivation management can prevent the occurrence of diseases. Let's talk about this in detail below.
I. Grape Anthracnose
The small black spots on grapes are not a healthy condition but a symptom caused by anthracnose, which usually occurs on fruits that are about to ripen. The clusters of grapes near the ground are more likely to be infected first, with the tip of the grape berries showing small black spots initially. Later, the spots will gradually expand and are more likely to occur in humid and rainy weather. The bright red clumps in the conidial masses are a very obvious characteristic. As the disease worsens, the fruit will gradually lose moisture and dry up, eventually forming僵果 (僵果 = mummified fruit) that remain attached to the pedicel and do not fall off. Most of the diseased fruit dry up and rot while the entire cluster remains on the tree.
II. Preventive Measures
1. Strengthen management
Timely prune the bad fruit with spots and all the diseased branches and leaves to prevent further infection in other parts. After the branches have expanded, it is necessary to tie the vines in time, pinch the tops of the branches, etc., to keep the grape trellis neat to enhance ventilation and effectively prevent the occurrence of diseases.
2. Spraying pesticides
In the south, grape trees are sprayed with pesticides from late April, and in the north from late May. Then, spray every 10-15 days with a 50% thiophanate-methyl or mancozeb 800x solution, or an 80% captophycin 700-800x solution.
Above is the information on what the small black spots on grapes are, understanding grape anthracnose, and the control methods for green plants and flowers. I hope it can help you in your daily life!