If green grape berries suddenly begin to darken, soften and rot, one should not think that the harvest is already lost. In most cases the problem can be stopped if the cause is determined in time and measures are taken.
Why grapes begin to rot
Most often wet weather is to blame. After prolonged rains or excessive waterings moisture remains for a long time on the clusters, creating ideal conditions for the development of fungal diseases.
Another common reason is a too dense bush. If the leaves completely cover the clusters, they are poorly ventilated and dry slowly after dew or rain.
Sometimes rot appears after damages to the berries. They can be left by wasps, birds, hail or even careless tying of the vine. Through small cracks the infection quickly penetrates inside.
What to do
- Regularly examine the clusters and immediately remove all damaged and rotten berries. Do not leave them on the bush or under it.
- Carefully thin the leaves around the clusters. Good air circulation significantly reduces the risk of rot development.
- Water the grapes only when necessary. If the soil remains moist after rains, additional watering is better postponed.
- After prolonged wet weather carry out a preventive treatment with an approved fungicide or biological preparation, following the manufacturer’s instructions.
- Remove fallen leaves, spoiled berries and other plant remains. Exactly in them the pathogens of diseases often persist.
Useful advice
In the second half of summer it is not worth feeding the grapes with a large amount of nitrogen fertilizers. They cause active growth of green mass, the bush becomes too dense, and humidity inside it increases. Much more useful is to use potassium-phosphorus feedings — they help the berries fill faster, strengthen the vine and increase the plant’s resistance to diseases.
A little attention to the vineyard during the season — and the clusters will remain healthy, and the berries will have time to fully ripen without losses.
This material was prepared by the editorial team using artificial intelligence tools. All information has been verified and edited before publication.