Every year when the apple is picked, some people will say that after the paper bag is taken off, the fruit is like white jade, there is no problem, and the heart is very happy, thinking that this year's commodity rate is high, and it can be sold for more money, who knows that when the guests harvest the fruit, there are a lot of apples that are beaten. The main problems are that some fruits have small red spots, some fruits have small black spots, some fruits have water cracks, some fruits have a deep groove with the fruit handle as the center, some fruits have black spots of bitter pox disease, and some fruits have sunburning...... What the hell is going on?
1. The small red dot is the spot deciduous fungus that infects the fruit surface, causing the formation of small red spots on the surface of the fruit. Apples are delicate in their skin, low resistance to diseases, and easy to get infected. Therefore, the prevention and control of spotted defoliation disease should be sprayed with water agent Qianlu (difenoconazole) 1500 times or Kailiang (pyraclostrobin) 2000 times, do not spray powder fungicide, so as not to pollute the fruit surface and affect the coloring, and at the same time pay attention to the prevention and control of spotted defoliation disease before bagging.
2. There are two reasons for the occurrence of black spot disease: one is the small black spot caused by the pink polytelospora infecting the fruit surface, and the other is the small black spot caused by the fruit surface of the Kang's mealybug. For small black spots caused by fungal damage, drugs can be combined with small red spot disease. The prevention and control of black spot disease around the calyx depression formed by the damage of Mealybug Kang's is mainly the prevention and control before bagging is grasped.
3. The occurrence of water cracks is caused by continuous high temperature after taking off the bag, sudden heavy rain or heavy water pouring underground, and the growth of skin and flesh is not synchronized. In order to reduce the occurrence of water cracked fruits, balanced irrigation should be maintained throughout the year, and the orchard should grow grass. After taking off the bag, the high temperature and drought should be relieved, and in order to relieve the drought, light watering should be carried out in alternate rows. Including the large fissure centered on the fruit handle, it is also related to calcium deficiency, because calcium can regulate the moisture in the fruit and increase the hardness of the peel. There are two peaks in the calcium requirement of the fruit, one is one month after flowering and the other is one month before fruit picking. Both water cracks and large fissures are large fruits, and small fruits are not. One of the main reasons is the lack of calcium in the later stage of the large fruit. Therefore, calcium should be sprayed once after taking off the bag. In addition, apply more organic fertilizer, less large chemical fertilizer, especially in the later stage of growth, the amount of top dressing can not be large, to prevent heavy rain or watering fruits grow too fast, and water cracked fruits will occur in high temperature weather.
4. Bitter pox is the most serious disease of bagged apples, and it is also caused by calcium deficiency. Due to the poor mobility of calcium, it is difficult to transport the calcium absorbed by the leaves into the fruit, so it is also difficult to solve the symptoms of calcium deficiency by spraying calcium after bagging. The key to solving the calcium deficiency is to spray high-quality calcium before bagging, which is easy to be absorbed by the fruit, and most of the calcium on the market is calcium chloride or calcium pinate, which is difficult for fruit trees to absorb, but the calcium is easy to be absorbed by the fruit, and the effect is good.
5. Reduce the occurrence of daily burning fruit, the fine skin and tender flesh of the fruit after taking off the bag, suddenly exposed to direct sunlight by the dark environment, encountering high temperature weather, the southwest direction of the crown is most prone to daily burning fruit, especially in the orchard with good group light, the daily burning fruit occurs more, and it is found in production practice that when someone takes off the bag, the leaves around the fruit are immediately removed, and the daily burning fruit is more. The correct way is to stop for a few days after the paper bag is taken off the bag and then pick the leaves, and wait for the fruit to adapt to the high temperature environment, and the peel is old, and then take advantage of the morning and afternoon or cloudy day to pick the leaves and burn the fruit less, and the fruit should also be careful not to turn the fruit at noon in the high temperature.
In order to promote coloring, some people spray potassium after taking off the bag, but it will pollute the fruit surface, and there are pittings when selling the fruit, and the fruit customers are reluctant to ask for it. Therefore, potassium supplementation must be done before taking off the bag. A year's hard work should not cause a low commodity rate and sell a lot of money because of a small mistake by you.
The orchard with more organic fertilizer not only has good brightness, good color, and sweet taste, but also has few problems with various fruits. Because the organic fertilizer is full of nutrients, the soil is well breathable, drought tolerant, and the fruit grows in a balanced manner, it is less affected by natural conditions, unlike only applying swelling chemical fertilizers, watering, and heavy rain, and the fruit grows fast and slowly, causing water cracks and black spots.
Author: He Jucai, lecturer of Zhongnong Le Fruit Science Research Institute
Source: Zhongnongle