Management of Apple before and after picking bags

Fruit management before and after apple bag picking is an important work before apple harvesting. Due to lack of understanding, lack of attention or lack of understanding of its management technology, many fruit growers often lead to unclean fruit surface, spread of diseases and pests, and greatly reduce the rate of commercial fruit. Therefore, to do a good job in the management of apples before and after picking bags is an important part to ensure the economic benefits of the whole year.

1. Time to pick up the bag

Picking bags at the right time is a technical measure to obtain high quality fruit. Take off the bag too early, the fruit is exposed for a long time, after the wind and rain in the sun, the fruit surface is easy to be rough, uneven coloring, long-time sun exposure will darken the color, and it is easy to cause diseases and insect pests; the bag picking time is too late, the fruit is exposed to light for a short time, incomplete coloring, light, low sugar content, poor flavor, easy to fade after a long time. The suitable time for bag removal is: yellow and green varieties should be removed 5-7 days before harvest, red mid-mature and middle-late-maturing varieties should be removed about 15 days before harvest, and red late-maturing varieties such as Red Fuji should be removed 20-30 days before harvest. The time to pick up the bag should also be advanced or delayed according to the market demand.

It is best to pick the bag on cloudy or cloudy days. If you pick bags on a sunny day, the bags on the east and north of the crown should be removed at 9: 12 a.m. and the bags on the west and south of the crown should be removed at 3: 6 p.m., so as to reduce sunburn caused by drastic changes in light intensity.

Second, the method of taking out the bag

Bagged apples do not need to be removed, but can be stored and sold. Single-layer paper bags and inner and outer conjoined bags should be opened before 12:00 and after 4 p.m., or the bag should be torn into umbrella strips over the fruit, and then removed after 4 or 6 days.

The method of removing double-layer paper bags. The inner layer of the red double-layer paper bag, first remove the outer bag, after 5-7 sunny days, remove the inner bag from 10:00 to 4 pm to avoid excessive temperature difference between the fruit surface. If there is a cloudy day, the time to remove the inner bag should be pushed back, so as not to form chlorophyll on the fruit surface after picking the bag, affecting the coloring effect; for the double-layer bag with black inner layer, first tear open the bottom mouth of the outer bag, take out the inner black bag, then tear the outer bag into strips and cover the fruit, after 6 or 7 days, remove the outer bag. For paper and film apples, only remove the outer paper bag and keep the inner film bag until the fruit is sold.

III. Management before and after bag removal

There are two main management tasks before and after fruit bag picking: one is to promote fruit coloring and strive for full red fruit; the other is to prevent and control all kinds of diseases and insect pests and strive for bright and clean fruit surface.

1. Spray a coloring agent. 200 times of the red agent No. 1 was sprayed 40 days and 25 days before harvest, and the hyperchromic effect could be seen 7 days after spraying.

two。 Pick the leaves. Pick the leaves 3-5 days after picking the bag, first remove the fruit leaves and shading leaves, and then remove the leaves within 5 cm of the upper part of the crown and the periphery of the fruit. Be careful to keep the petiole. Leaves should not be picked too early or too much, and the amount of leaves picked should be 10% to 15% of the total amount of the whole tree, and no more than 30% at most, otherwise it would affect flower bud differentiation.

3. Turn the fruit. The fruit was turned 4-8 days after picking the bag, and the sunny side of the fruit was stained within 8 days after picking the bag (except rainy days). Four days after picking the bag, the sunny side of the fruit was almost all colored. At this time, the fruit will be gently turned 180 °, the negative side will be turned to the sunny side, and the shady side will be fully colored within 15-20 days. Turning fruit should be carried out in the morning or afternoon on cloudy, cloudy or sunny days. Avoid turning fruit at noon to prevent sunburn. It is also possible to turn fruit twice for varieties with short stalks and areas with large temperature difference between day and night at high altitude. First turn 90 °, then turn 90 °in the same direction after 7 °10 days.

4. Lay a reflective film. Immediately after taking off the bag, spread a long white reflective film on both sides of the tree plate and trunk, and compact it with rope or plastic soil bag. The reflective film can increase the average relative light intensity in the crown by more than 70%, increase the direct light in the lower part of the crown by 18.6% to 34.1%, the reflected light by 5 times compared with the control tree, and the coloring rate of drooping calyx depression is up to 98%. The rate of all red fruit is 85%.

5. Control diseases and insect pests. After fruit bagging, with the continuous growth of fruit, a large amount of calcium and some nutrients are consumed. After picking the bag to before harvest, the fruit still has a period of exposure, so, in 2-3 days after picking the bag, spray 300 times the net liquid of the fruit surface in time to protect the fruit. If you encounter continuous rain and rainy autumn after picking the bag, the fruit is vulnerable to black spot disease, bitter acne disease, pox spot disease, wheel rotten fruit disease and fruit cracking, it should be sprayed up to 2116 days, Nanxin or Jinlishi to increase calcium in 2-3 days after picking the bag. If black spots, black spots and rotten fruit wheels have appeared on the fruit surface after removing the bag, you can spray internal absorption fungicides, such as doxorubicin, Jinlux, etc., 2-3 days after removing the bag, to prevent the spread of the disease. But spraying must be done 25-30 days before fruit picking. Spray calcium must be sprayed on the fruit surface, and it must also be sprayed fine, evenly and thoughtfully.

Due to the lack of light, the sugar content of bagged fruit is reduced by about 1 degree. Therefore, in addition to the comprehensive management of more organic fertilizer and more phosphorus and potassium fertilizer, the harvest can be postponed for 10 days in order to increase sugar and color.

Chai Quanxi Song Suzhi, Vocational Education Center, Gaocheng District, Shijiazhuang City