How to prevent and control grape gray mold? A full analysis of practical measures

Grape gray mold, commonly known as rotten flower clusters, is a relatively serious disease occurring worldwide today, and it can occur during all grape growing and storage periods. Among grape diseases, it causes the most severe losses, so what do the symptoms of grape gray mold look like? How should it be prevented and controlled? Let's take a look together.

1. Disease symptoms

Grape gray mold harms inflorescences and fruits, and can also harm leaves and new shoots. When there are many inflorescences, the disease occurs before flowering. In the early stage of inflorescence infection, it looks as if it has been scalded by boiling water, appearing dark brown, with the diseased tissue soft and rotting, and the surface densely covered with a gray mold layer. The affected inflorescences wither, and young fruits drop off very easily. After the fruit stalk is infected, black sclerotia will also be produced on the lesions; when fruits are infected at maturity, light brown lesions first appear, which quickly spread to the entire fruit, causing the fruit to rot. In severe cases, new shoots and leaves can also be infected, producing irregular brown lesions, and the lesions sometimes also show irregular ring patterns. If infected by the pathogen during storage, the fruits will also discolor and rot.

2. Occurrence pattern

The disease generally occurs twice, once around flowering and the second time during fruit ripening. In spring, when the temperature is relatively low and the air humidity is relatively high, rain will cause the fruit flesh to split, and the pathogen will take the opportunity to enter, causing the fruit to rot. The onset temperature for gray mold is 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 when gray mold occurs. 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 the occurrence of grape gray mold.

3. Prevention and control measures

First, choose varieties with strong disease resistance. When excessive vegetative growth occurs, control nitrogen fertilizer, spray paclobutrazol to inhibit new shoot growth, and enhance disease resistance. Spraying chemicals before flowering is the key period for prevention and control. You can spray a 1000-fold garlic oil solution for prevention. For fertilizer and water, more attention should be paid to prevention and control, and trace elements should be supplemented appropriately. Weeds in the orchard should be removed regularly to keep the orchard ventilated and allow light through, 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 prevention and control measures for grape gray mold. I hope it can help you. If you want to learn more related knowledge, please stay tuned to us.