What causes severe berry drop in Summer Black grapes?

Summer Black grape is an excellent variety with characteristics of disease resistance, high yield, early maturity, and good taste, but during cultivation, Summer Black grapes often show severe berry drop, causing huge losses to yield. So what is the reason for severe berry drop in Summer Black grapes? Let's take a look together.

1. Its own genetic inheritance

Summer Black grapes are inherently prone to dropping flowers and fruit. This is a very common problem. Other grape varieties also experience berry drop, but Summer Black grapes simply drop more severely than other varieties. The berries of Summer Black are relatively large, and after the fruit ripens, the fruit is relatively soft and extremely easy to fall off the pedicel. This kind of genetic inheritance problem in the variety is currently very difficult to solve.

2. Improper management

Improper planting management can also cause severe berry drop in Summer Black grapes. For example, if too much fruit is retained, the gaps between berries are too tight, and the fruit does not have enough space to grow, then as the fruit gradually grows and swells, the berries crowd each other and are squeezed off. The best solution is reasonable flower and fruit thinning, controlling the number of berries and the gaps between berries well, and controlling the ratio of fruit to leaves properly. In addition, a deficiency of boron or zinc during the flowering period, or improper water and fertilizer management, can also lead to severe berry drop, such as applying too much nitrogen fertilizer during the flowering and fruiting period.

During the middle and late flowering period of Summer Black grapes, if the weather deteriorates and there is excessive rain, causing waterlogging in the field and high air humidity, the fruit will absorb too much water, and the pedicel cannot bear it, resulting in berry drop. At the same time, reduced sunlight can also affect the photosynthesis of the leaves, leading to insufficient synthesized nutrients. The fruit does not have enough nutrients for growth and development, which may also cause berry drop.

4. Diseases

When Summer Black grapes are infected by fungal diseases, such as anthracnose and ripe rot, berry drop can also occur. Many fruit growers think disease control should involve spraying after fruit set, or even only when coloring begins, but by then it is already too late. This is because prevention of fungal diseases should begin with spraying during their latent period. Fungicides can be sprayed before the flowering period to prevent anthracnose and ripe rot, giving a better control effect. In addition, dead branches and fallen leaves on the ground should be cleaned up in time to avoid breeding fungi.

The above is an introduction to the causes of severe berry drop in Summer Black grapes. We hope it can help you. If you want to learn more related knowledge, please stay tuned to us.