How to prevent and control apple fruit cracking? Growers, master these key points

In recent years, apple fruit cracking is a common disease in production, seriously affecting fruit quality. The causes and prevention methods of apple fruit cracking are introduced below.

Apple fruit cracking manifests as cracks or fissures on the fruit. There are various forms of fruit cracking: some split longitudinally from the side of the fruit, some extend from the stem cavity crack toward the side of the fruit, and some extend from the calyx cavity crack toward the side. The cracks are irregular, some deep and some shallow. The cracks are prone to infection by diseases, leading to fruit rot.

I. Causes of fruit cracking If the soil is excessively dry in the early stage of fruit growth, and the fruit enters the color-turning stage to near maturity, the stomata open, and the cell arrangement at the suture line of the fruit is poorly compacted. If continuous rainfall or heavy rain occurs, causing a sharp increase in soil moisture, the tree roots rapidly absorb water and the fruit expands sharply, and the fruit skin is prone to bursting and cracking. In addition, areas damaged by pesticide injury or pests and diseases often cause part of the fruit skin to stop growing, and this point will become the starting point of fruit cracking. After the skin on the sunny side of the fruit is exposed to direct sunlight, small sunburn marks appear, the toughness of the fruit skin decreases, and fruit cracking is likely to occur. For young trees or top-grafted trees in the early fruiting stage, the new shoots grow vigorously and the branches are upright, which easily causes fruit cracking; branches with an open angle and moderate growth vigor have less fruit cracking.

II. Prevention and control methods To reduce the fruit cracking rate, soil management must be strengthened and organic fertilizer increased. Fertilization should be based mainly on organic fertilizers such as farmyard manure and green manure, with attention to balanced fertilization, controlling the amount of nitrogen fertilizer, and timely supplementing calcium, boron, potassium and other fertilizers. Through measures such as deep plowing of the orchard and increased application of organic fertilizers, increase the soil organic matter content and improve soil structure, enhancing its water storage and moisture conservation capacity. Irrigate at the right time and in the right amount to stabilize the soil moisture content and prevent the fruit skin cells from stopping growth too early. In addition, pruning techniques should be used to control tree vigor and maintain a moderate state of tree vigor, which can also effectively reduce the fruit cracking rate. Bag the young fruit with paper bags during the young fruit stage to protect the fruit, avoid external damage to the fruit, and reduce the stimulation of rain and light on the fruit, which can significantly reduce the fruit cracking rate. In addition to improving production techniques, 2 to 3 weeks after full bloom, spray the young fruit with 500 to 600 times Lvxianwei (a fruit preservative) plus 0.3% urea solution, once every 1 week, which also has a good effect on reducing fruit cracking.