What are the causes of premature decline in grapes? Detailed explanation of prevention and control methods
Grape is one of the more popular berries on the market. In recent years, market demand has continued to increase, and it has attracted many farmers to grow it. However, during the growing process, premature decline of grapes often occurs. So what causes premature decline in grapes? How should it be prevented and controlled? Let's learn about it together.
1. Causes of premature decline in grapes
1. Improper pruning
If the main vine is pruned and left too long, the tendency to rush forward is serious, and no attention is paid to the cultivation and renewal of the rear fruiting branches, the retained branches are too long and the permeability is poor. Over time, the rear fruiting branch groups will die. When the main vine exceeds the trellis surface and there are no reserve branches at the rear, it cannot be retracted, and premature decline occurs.
2. Overloading with fruit
Too many fruiting branches are retained, the permeability is poor, and no attention is paid to retaining clusters and fruit, resulting in an imbalance between the aboveground and underground nutrients. This is especially likely during the rainy season when water accumulates easily, causing insufficient soil oxygen supply and leading to root suffocation and root death. Fruit quality decreases, leaves fall early, dead branches become serious, and sometimes leaf yellowing also occurs. It cannot recover for ~3 years, and in severe cases the plant dies.
3. Improper fertilizer and water management
Improper fertilizer and water management is also one of the causes of premature decline. Many fruit growers emphasize nitrogen and neglect phosphorus and potassium when fertilizing; they emphasize chemical fertilizers and neglect organic fertilizers; they emphasize topdressing and neglect base fertilizer. During the growing period, excessive nitrogen fertilizer is applied while the combination of nitrogen, phosphorus, and potassium is neglected. They pursue only quick-acting fertilizers while ignoring the role of base fertilizer and organic fertilizer. This leads to decreased fruit quality and also causes the vines to become heavy, consume large amounts of nutrients, and inhibit the sprouting of basal buds. In addition, too many irrigations can also lead to excessive vegetative growth, closed branches and leaves, aggravated pests and diseases, intensified tree vigor decline, and the formation of premature decline.
4. Poor pest and disease control
The spread of diseases such as black pox and anthracnose causes serious fruit rot, resulting in a significant decrease in quality and yield. In addition, when insect pests are severe, they can lead to insufficient stored nutrients in the tree body, reduced sprouting rate, fewer effective branches, weakened tree vigor, and serious yield reduction.
2. Prevention and control methods
1. Reasonable pruning
Generally, the extension branch of the main vine should not be pruned too long; the length generally should not exceed 50-60 cm. This can maintain the growth advantage of the lower branches and improve photosynthetic efficiency. Also pay attention to the cultivation and renewal of fruiting branch groups. Generally, the main vine must be renewed once every 3-4 years to avoid bare lower sections.
2. Reasonable retention of branches and fruit
Regarding the amount retained on fruit trees, generally strong branches retain 2 clusters, while weak branches or renewal branches generally retain 1 cluster or no cluster. The amount of branches retained is closely related to yield, quality, and growth vigor. If too many branches are retained, the plant load is too large, the permeability is poor, and flower and fruit drop is very likely to occur, resulting in low quality. Therefore, retain branches and fruit reasonably, do not be greedy for fruit, achieve high yield and high quality, and eliminate the alternate bearing phenomenon.
3. Strengthen management
When fertilizing, increase the application of organic fertilizer and compound fertilizer, reduce nitrogen fertilizer application, and improve the drainage and irrigation system to facilitate drainage and reduce waterlogging, thereby improving tree vigor.
4. Strengthen pest and disease control
In late March of early spring, spray lime sulfur mixture over the entire orchard, which can provide excellent prevention and control of pests and diseases. During the growing period, spray Bordeaux mixture, chlorothalonil, thiophanate-methyl, and others alternately to effectively control vine blight, white rot, downy mildew, and others. At the same time, for insect pests, scrape and apply to old bark, cut and apply to diseased shoots, clean up diseased leaves and diseased fruit, and burn them centrally to reduce insect sources.
The above is an introduction to the causes of premature decline in grapes and the prevention and control methods. I hope it can help you. If you want to learn more related knowledge, please stay tuned to us.