Control of apple cracking disease

In recent years, apple fruit cracking is a common disease in production, which seriously affects the quality of apple fruit. The causes and control methods of apple fruit cracking are introduced as follows.

The cracking of apple fruit is characterized by cracks or cracks in the fruit. There are many forms of fruit cracking: some split longitudinally from the side of the fruit, some extend from the pedicle depression to the side of the fruit, and some extend from the calyx crack to the side, the crack is irregular, some deep and shallow. Cracks are susceptible to diseases and lead to fruit decay.

The main results are as follows: 1. the reason for fruit cracking is that if the soil is too dry in the early stage of fruit growth, the fruit enters the color conversion period to near maturity, the stomata open, the cells in the suture line of the fruit are poorly arranged, and the soil moisture increases sharply in the event of continuous rainfall or rainstorm. The root system of the fruit tree absorbs water rapidly and makes the fruit expand rapidly, and the fruit epidermis is easy to crack and crack. In addition, the parts damaged by drugs, diseases and insect pests often cause part of the pericarp to stop growing, which will become the starting point of fruit cracking. After the pericarp on the sunny side of the fruit is exposed to direct sunlight, small sunburn marks appear, the toughness of the pericarp decreases, and the fruit is easy to crack. In the early fruiting stage of young trees or high grafted trees, the new shoots grow vigorously and the branches are erect, which are easy to cause fruit cracking; there are few fruit cracking on the branches with open angles and moderate growth.

Second, in order to reduce the rate of fruit cracking, we must strengthen soil management and increase the application of organic fertilizer. Fertilization should be based on farm manure, green manure and other organic fertilizers, pay attention to balanced fertilization, control the amount of nitrogen fertilizer, and timely supplement calcium, boron, potassium and other fertilizers. Through measures such as deep ploughing of orchards and increasing application of organic fertilizers, the content of soil organic matter and soil structure were improved, and the ability of storing water and preserving soil moisture was increased. Timely and appropriate amount of water, stabilize the soil water content, do not let the pericarp cells stop growing prematurely. In addition, the tree potential should be controlled by pruning technology to maintain the moderate state of the tree potential, which can also effectively reduce the rate of fruit cracking. Paper bags in the young fruit stage can protect the fruit from external damage and reduce the stimulation of Rain Water and light to the fruit, which can significantly reduce the fruit cracking rate. In addition to improving the production technology, the young fruit can also be sprayed with 500-600 times green Xianwei (a fruit antistaling agent) plus 0.3% urea solution every other week, which also has a good effect on reducing fruit cracking.