What to do when bagged apples develop shriveling and cracking
Bagged apples tend to develop micro-cracks and shriveled skin after the bags are removed. This phenomenon falls into two cases: first, the fruit has already developed shriveling and cracking inside the bag, and once the bag is torn off it becomes even more severe; second, there is no abnormality when the bag is torn off, but soon after coloring, micro-cracks, shriveled skin, softening and other undesirable phenomena occur.
The main reason is that during the early and middle stages of apple growth there is high temperature and drought, and the temperature inside the bag during the day often exceeds 50 degrees, while under normal conditions the temperature should remain at 35-45 degrees. The first fruit expansion period is short and growth stops early; in addition, the fruit inside the bag has thin, delicate skin, and after the bag is torn off in the later stage, if water is sufficient, the second expansion of the fruit will speed up. Because the fruit flesh cells divide quickly while the skin cells divide slowly, the difference in the division speed of the inner and outer cells causes the fruit to develop micro-cracks. After the fruit micro-cracks, it loses water, which in turn causes the fruit to shrivel and soften. In addition, a calcium deficiency in the fruit also easily causes this phenomenon.
Measures to prevent bagged apples from developing shriveling and cracking:
1. After the flowering period, when high temperature and drought weather occurs, water can be sprayed intermittently on the leaf surface in the evening (around sunset) until the leaves drip. In addition, adding 1% monopotassium phosphate or amino acid calcium to the water when spraying gives a better effect.
2. Spray a 2% amino acid calcium aqueous solution during the first and second fruit expansion periods (spraying in the evening gives a better effect).
3. Spray naphthalene acetic acid once each in the early and middle stages of the second fruit expansion.
4. Pay attention to removing leaves and turning the fruit during the coloring period.