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 Summer Black grapes often show severe berry drop during cultivation, causing huge losses to yield. So what is the reason for severe berry drop in Summer Black grapes? Let's take a look.
1. Its own genetic inheritance
Summer Black grapes themselves are prone to dropping flowers and fruit. This is a very common problem; other grape varieties also experience berry drop, only Summer Black grapes drop more severely than other grape varieties. The berries of Summer Black are relatively large, and after the fruit ripens it becomes relatively soft and very easily falls off the stalk. This kind of varietal genetic problem is currently very difficult to solve.
2. Improper management
Improper planting management can also lead to severe berry drop in Summer Black grapes. For example, when too much fruit is retained, the gaps between berries are tight, and the fruit has no enough room to grow; 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, boron or zinc deficiency during the flowering period, or improper water and fertilizer management, can also cause severe berry drop, for example applying too much nitrogen fertilizer during the flowering and fruiting period.
3. Climatic reasons
During the middle and late flowering period of Summer Black grapes, if the weather deteriorates and there is too much rain, causing waterlogging in the field, and the air humidity is high, the fruit absorbs too much water, and the stalk cannot bear it, resulting in berry drop. At the same time, reduced sunlight also affects 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 white rot, berry drop also occurs. Many fruit growers think disease control should be sprayed after fruit set, or even only when coloring begins, but by then it is already too late. Because prevention of fungal diseases should begin with spraying during their latent period; spraying agents before the flowering period to prevent anthracnose and white rot gives better control results. 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 reasons for severe berry drop in Summer Black grapes. We hope it can help you. To learn more related knowledge, please follow us.