Some "rock candy heart" apples often appear on the market. These apples become very sweet after being saccharified, so they are also sought after by some fruit farmers. But in fact, the "rock candy heart" apple is a physiological disease during the growth of apples - apple water core disease, also called glycation disease. In general, apples suffering from this disease will do more harm than good. Although some vendors will make wild claims about it, don't believe it. Let’s take a closer look at the symptoms, causes and prevention measures of apple water core disease. We also recommend that consumers and fruit growers should not blindly pursue this kind of “rock candy heart” apples.

Apple water core disease generally occurs during the maturity and storage period of apples, and mainly harms apple fruits. In the early stages of the disease, it is generally difficult to tell from the appearance, but the pulp of the affected area will become sweeter due to the return of sugar, and the internal pulp tissue will appear transparent and water-soaked or harden, brown, and rot. In severe cases, The peel area will also show symptoms such as water-soaked transparency, browning, and rot. As the disease gradually worsens, fruit cracking sometimes occurs, especially from 1 month before apple picking to 1 month after storage, because the temperature is higher at this time, which is more likely to cause the entire apple to brown and rot within a week. .

For apple planting areas, if there are problems such as soil acidification, hardening, and low organic matter content, it is easy to cause the root system of apple trees to be underdeveloped, which will lead to calcium deficiency in apples and induce diseases. In addition, especially in plots where nitrogen fertilizer is applied, the occurrence of apple water core disease is more likely to be aggravated. When fertilizing, if the content of trace elements such as nitrogen, potassium, and magnesium in the soil is too high, it will reduce the effectiveness of soluble calcium in the soil and inhibit the absorption of calcium by apples. Insufficient calcium nutrition can easily induce apple water core disease. At the same time, organic fertilizer can promote the absorption of calcium nutrients from the soil by the roots of fruit trees. If the orchard uses large amounts of chemical fertilizers for a long time, does not use organic fertilizers, or uses insufficient organic fertilizers, it will also reduce the effective absorption of calcium by apples.

Rational water and fertilizer irrigation is one of the necessary conditions to ensure balanced soil nutrition, and it is also the main way to supplement calcium for apples. It is recommended to apply more decomposed organic fertilizer, farm manure or biological fertilizer as much as possible to increase the organic matter content in the soil and enhance the effectiveness of fruit tree roots in absorbing calcium from the soil. In terms of watering, during the apple fruit expansion stage, fruit development and flower bud differentiation are carried out at the same time. This is the critical period when apples need water, and the relative soil humidity should be maintained at around 60-70. Apples should be harvested in time after they mature to prevent over-ripening of the fruit. Varieties susceptible to water core disease are best harvested in advance. In addition, when apples are ripe, they should be harvested early in places with higher temperatures, and later in places with lower temperatures.