The grapes shrank after the rain. What is the reason?

The grapes shrank after the rain. What is the reason?

I don't know where you are. I wonder if the grapes you cultivate are European (like dry and rainy climate)? American strain or European-American hybrid strain (more suitable for growing in hot and humid climate than European strain)?

Personally, I think that your "shrinking grapes after rain" is mainly caused by climate factors.

There has been a great contrast in climate recently. Temperature affects the evaporation of plant water. The higher the temperature, the greater the transpiration. When transpiration exceeds the ability of grape roots to absorb water, the growth of grape organisms is inhibited, leaves turn yellow and fall off, fruits stop growing, and even shrink due to water loss. After rain, high temperature occurs, and when it meets rain (occasionally, if the temperature is too high for a long time, the fruit will still shrink), which leads to physiological inadaptability of grape plants, such as fruit shrinkage, yellowing, leaf falling off and so on.

Control methods: select varieties with strong resistance and suitable for local cultivation; Planting grapes needs to choose plots with deep and fertile soil; When maintaining at ordinary times, we should deliberately control watering to make the roots grow deeper, which is beneficial to the development of roots and improve the adaptability to the weather; When the weather is very hot, if the leaves are wilting, spray them on the leaves to reduce water evaporation; Appropriate shading can be used to reduce transpiration when conditions permit.

Now is the rainy season, and it is also the high incidence period of black bean disease (black eye disease), downy mildew and white rot, so we should pay attention to disease prevention and control.