What are the latest control measures for grape gray mold?
Grape gray mold, commonly known as rotten flower cluster, is a relatively serious disease occurring worldwide, and it can occur during the entire grape growing and storage period. Among grape diseases, it causes the most serious losses, so what are the symptoms of grape gray mold? How should it be controlled? Let's take a look.
1. Disease symptoms
Grape gray mold harms inflorescences and fruits, and also harms leaves and new shoots. When there are many inflorescences, the disease occurs before flowering. In the early stage of inflorescence disease, it looks as if it has been scalded by boiling water, appearing dark brown, the diseased tissue becomes soft and rotten, and the surface is densely covered with a gray mold layer. The affected inflorescences wither, and young fruits fall off very easily. After the fruit stalk is infected, black sclerotia are produced on the lesions; when the fruit is infected at maturity, light brown lesions first appear, then quickly spread to the entire fruit, causing the fruit to rot. When the disease is severe, new shoots and leaves can also be infected, producing irregular brown lesions, and the lesions sometimes also show irregular concentric rings. If infected by the pathogen during storage, the fruit will also become discolored and rot.
⟦NL>2. Occurrence pattern
Disease onset is generally divided into two periods, one before and after flowering, and the second at fruit ripening. In spring, when the temperature is relatively low and the air humidity is relatively high, rain causes the fruit pulp to split, and the pathogen takes the opportunity to enter, causing the fruit to rot. The onset temperature for gray mold is around 20 degrees, and the air humidity is above 85%. If the air humidity reaches above 90%, the disease will be extremely severe. Therefore, the rainy season in spring is the period of gray mold onset. In addition, improper management of gray mold, such as poor ventilation, insufficient light, low-lying terrain, excessive application of trace elements, and so on, can all lead to grape gray mold.
3. Control measures
First, choose varieties with strong disease resistance. When excessive vegetative growth occurs, control nitrogen fertilizer and spray paclobutrazol to inhibit new shoot growth and enhance disease resistance. Spraying chemicals before flowering is a key period for control; garlic oil can be sprayed at 1000 times dilution for prevention. Pay more attention to fertilizer and water management, and appropriately supplement trace elements. Regularly remove weeds in the orchard, keep the orchard ventilated and well lit, test whether the indoor temperature is suitable, achieve good disease control results, ensure soil quality, and check and kill pests.
The above is an introduction to the control measures for grape gray mold. I hope it can help you. To learn more related knowledge, please follow us.