Fruit cracking affects grape yield and appearance how to prevent grape fruit cracking

Grape fruit cracking phenomenon seriously affects grape yield and fruit quality, and reduces the economic income of fruit growers.

Grape cracked fruit

1. The main causes of fruit cracking.

1.1 insect pests

The insect pest not only harms the leaves, but also the young grape fruit. During the expansion period, the damaged grape can not grow with the pulp cells at the same time because of the corkiness of the pericarp. With the expansion of the pulp cells, cracks are formed at the edge of the insect spots.

1.2 abuse of swelling agent

In recent years, as large grape is favored by dealers and consumers, in order to pursue higher economic benefits, many fruit growers abuse expansion agents at will. According to the investigation, the occurrence of fruit cracking was positively correlated with the concentration, method and fruit size of the expanding agent.

1.3 improper irrigation

From the early stage of grape ripening to mature stage, fruit growers irrigate a large amount of water in order to increase yield. Due to the sharp fluctuation of water content in orchard soil, the water absorption capacity of pulp cells is significantly higher than that of pericarp cells. The rate of water absorption and expansion of pulp cells is higher than that of pericarp cells.

1.4 calcitonin deficiency

Calcium takes part in the formation of cell wall in the form of calcium pectin, which can reduce the hydration of protoplasts, regulate the activity of protoplasts, and make the water filling degree, viscosity, elasticity and permeability of cells suitable for the normal growth of plants. it is also an activator of some enzymes and coenzymes. The content of calcium in grapes is higher than that in phosphorus, but because calcium can not be reused in plants, the content of calcium in fruits is significantly lower than that in leaves. Before grape ripening, in order to expand the fruit, many fruit growers apply a large amount of chemical fertilizer, especially nitrogen and potassium fertilizer, while silicon and calcium fertilizer is too little or no application, or never foliar spraying calcium fertilizer, resulting in green fruit, pericarp cells and pulp cells are not tough and elastic, resulting in fruit cracking.

Grape cracked fruit

2. Effective measures to prevent fruit cracking.

2.1 use of growth regulators with caution

The growth regulators of cytokinins (dilators) should be used carefully in the young fruit stage of grape. The physiological characteristics of the original varieties should be maintained.

2.2 reasonable load

The small scaffolding retains 6-8 ears on each main vine. At the same time, adjust the load with other summer shearing measures. The yield is controlled at 1500 ~ 2000 per 666.7 mu. Because the yield is reasonable, it can achieve normal coloring and improve the quality without manual spraying of colorant.

2.3 timely control of green bug bug and grape black pox

In the three critical periods of grape shoot second and third leaf, inflorescence separation and post-flowering, 1000 times of 5% cypermethrin water emulsion + 1000 times of 5% acetamiprid microemulsion, or 1500 times of 40% chlorpyrifos EC, or 2000 times of 20% carbosulfan EC, or 1000 times of methylaminoavermectin and 2000 times of imidacloprid wettable powder were used alternately. Whole tree spray.

2.4 implement grass or mulch

Adopting internal grass or ground mulching in vineyard can reduce the serious fluctuation of soil water content and prevent soil from excessive drought or waterlogging. Small water should be irrigated many times. According to the weather conditions, if the temperature is high, you should properly irrigate small water or spray water from the orchard to adjust the temperature of the tree and the garden.

2.5 increase the application of organic fertilizer, silicon and calcium fertilizer

In the full fruiting stage, the general trees were treated with organic fertilizer 10 times, phosphorus and potassium 0.15-0.25 times, silicon-calcium 0.25-0.5 times.

Grape bagging is carried out according to the yield to reduce the water absorption of the fruit surface.