What causes flower drop and fruit drop in grapes
Grapes are a type of grape, but they have a better taste and are sweeter than ordinary grapes, and are deeply loved by consumers on the market. However, during their growth period, flower drop and fruit drop occur, which greatly affects the yield of grapes. So what causes flower drop and fruit drop in grapes? Let's take a look.
1. Variety characteristics
Flower drop and fruit drop in grapes are somewhat related to their variety characteristics. Some varieties have defective female flower structures, some varieties show signs of stamen degeneration, or the pollinator tree arrangement for female-fertile varieties is unreasonable, all of which can cause flower drop and fruit drop.
2. Physiological fruit drop
Throughout the entire growth process of grapes, there will be 1-2 instances of physiological flower drop and fruit drop. Generally, when the grape berries grow to 3-4 mm, some berries stop developing due to malnutrition and fall off, which is called physiological fruit drop.
3. Insufficient nutrition
If the nutrients stored in the tree are insufficient in the early growth stage of grapes, the number of incomplete flowering periods increases, the development of the pistil is poor, and the pollen germination rate is low, causing relatively severe fruit drop. In addition, grapes have a large number of flowers, so the consumption of water and nutrients is also relatively large. If trace elements are lacking during the flowering period of grapes, especially potassium, phosphorus, boron, etc., their pollen fertilization ability will decline, causing flower drop and fruit drop.
4. Improper management
During the flowering and fruiting period of grapes, the demand for water and nutrients is relatively large, but if fertilization and watering are improper during this period, flower drop and fruit drop will also occur, such as excessive application of nitrogen fertilizer and excessive watering. Also, when techniques such as shaping, pruning, and pinching are not up to standard, the contradiction between vegetative growth and reproductive growth during the flowering period intensifies, which can also lead to flower drop and fruit drop.
5. Poor climate
The suitable temperature during the flowering period of grapes is between 20-25 degrees. If the temperature during the flowering period is lower than 10 degrees, it will affect its normal flower bud differentiation. If the temperature during the flowering period is lower than 14 degrees, its flower organs will grow poorly and fall off. If the temperature during the flowering period is higher than 35 degrees, the flower organs will also lose water, wither, and die. If there is continuous rainfall during the flowering period, the corolla cannot fall off normally, and the anthers cannot shed pollen normally, resulting in decreased pollination quality and causing flower drop and fruit drop. In addition, if there is insufficient light before flowering, the assimilation of its new shoots will decrease, and the nutrient supply to the fruit clusters will become strained, causing flower drop and fruit drop.
The above is an introduction to the causes of flower drop and fruit drop in grapes. We hope it can help you. To learn more related knowledge, please follow us.