What should you pay attention to before and after bagging apples?

Bagging can make the fruit surface delicate and smooth, bright and beautiful color, prevent the harm of diseases and insect pests, reduce the pollution of pesticides and dust, produce pollution-free, high-quality fruit, and effectively enhance the commercial value of the fruit. However, the bagging technology of some fruit growers is not standard, and the measures are not in place, resulting in poor quality of bagged apples, low excellent fruit rate, and even the adverse consequences of high input and low yield. Practice has proved that apple bagging should also pay attention to the following technical points:

There are five choices for bagging.

Trees and fruits that are bagged must be strictly selected. Select excellent varieties with high economic value. The second choice is the orchard with better management. The third selection has strong growth and good structure. Angle opening (90-120), ventilated and transparent plants. Four selection of flowers and fruit thinning in place, the load of reasonable trees (fruit spacing to maintain 20-25 cm, leaving about 10,000 fruits per mu). Five selection of well-developed, fruit-shaped, oblique and drooping fruit, and then bagging is appropriate. This is the basic condition to ensure excellent fruit.

2. The bagging time should be appropriate.

Bagging time should not be advanced or postponed. Premature will affect the development of young fruit, resulting in fruit drop; too late, the fruit surface is difficult to turn green, the pericarp is rough, and the appearance quality is poor. The suitable time for bagging is 35-40 days after falling flowers (in the first and middle of June), and it should be finished in a short time. From 9 am to 6 pm during the day, the dew is not dry in the morning and there is no bagging on cloudy and rainy days.

3. Drugs should be carefully selected before bagging.

The period from flowering to bagging is the period of exuberant division of pulp cells, the fruit surface is young and tender, and it is very sensitive to pesticides. Improper application of medicine or fertilizer in this period will lead to the cracking of fruit lenticels and form large cork lenticels, which will make the fruit surface rough and even produce rust spots. In order to ensure that the bagged fruit is clean, smooth and gorgeous. In order to improve the rate of high quality fruit, three points should be achieved when using medicine or foliar fertilizer to control diseases and insect pests in the young fruit stage: first, the times of spraying should not be too much and the concentration should not be too high, so as to reduce the stimulating effect of pesticides on fruit surface as far as possible. The second is to avoid using pesticides and fungicides that can easily cause fruit rust (such as pesticides containing copper ions and organophosphorus). Third, foliar spraying fertilizer, try not to use potassium dihydrogen phosphate, urea and other chemical fertilizers, can apply nutrient liquid fertilizer (such as organic humic acid fertilizer or amino acid compound micro-fertilizer, etc.).

4. Calcium supplement should be strengthened before bagging.

Apple is a fruit tree with high calcium requirement, and calcium-deficient fruits are prone to bitter pox disease, pox spot disease, fruit cracking disease and so on. The critical period of calcium demand for apple is 30-40 days after flowering, and the transpiration of the fruit after bagging is very small, so the calcium transferred to the fruit by the pulling force of transpiration liquid flow decreases. Therefore, foliar spraying of calcium should be carried out for 2-3 times from one week after falling flowers to before bagging, and generally apply calcium amino acid, calcium humate, calcium chloride and so on, so as to avoid physiological diseases of fruit caused by calcium deficiency.

5. The quality of fruit bags should be guaranteed.

The quality of fruit bag is an important factor to determine the success of bagging fruit cultivation. At present, there are many kinds of fruit bags, including double-layer paper bags, single-layer paper bags, plastic microfilm bags and so on. But the quality of double-layer tricolor paper bags is the best, such as Taiwan Jiatian, Shandong Kaixiang, Aimin, Hebei Shunda, Shaanxi Dudu, Seiko and so on. Unqualified products such as no manufacturer, no trademark, no inspection certificate, rough production, poor paper quality, no anti-bacterial treatment, poor water resistance, poor air permeability, uneven wax coating in the inner bag, etc., can not be used. The plastic microfilm bag is cheap and can reduce the investment of bagging, but the effect of improving fruit surface quality is not as good as that of double-layer paper bags, and sunburn is easy to occur, especially in dry orchards without irrigation conditions, sunburn phenomenon is more serious in high temperature and drought weather, should be paid attention to.

6. Bagging operation should be standardized.

Spray germicidal and insecticidal agents 1-2 days before bagging, and bagging can be done after the liquid is dry. When bagging, first use your hands to open the fruit bag, so that the fruit bag is inflated. Aim the longitudinal opening of the fruit bag at the pedicel, ride the opening on the pedicel, fold the mouth of the bag left and right laterally, then bend the pre-embedded tie wire of the mouth of the bag into a V shape to clamp the mouth of the bag. During the operation, the leaves and secondary shoots should not be put into the bag; the silk should be clamped on the paper bag and should not be twisted on the fruit stem so as not to damage the fruit stem and cause fruit drop; the paper bag should be inflated and the young fruit should be suspended in the bag to prevent the apple fruit sunburn disease caused by the fruit surface sticking against the inner wall of the paper bag.

7. Check regularly after bagging

After the end of bagging and windy and rainy weather, it should be checked generally. Check whether the bag is tightly bound, whether the inflated paper bag is out of shape, and whether the young fruit is attached to the bag wall. The bag should be opened every 10-15 days to check whether there are pests in the bag (insects and eggs are entangled when bagging, or the mouth of the bag is not tightly tied, pests are harmed into the bag) and the occurrence of diseases, sunburn and so on. If problems are found, necessary measures can be taken according to the degree of harm.