1.Apple varieties and storage characteristics
Apple is a typical respiratory climacteric fruit, postharvest with an obvious after-ripen process, the starch converted into sugar gradually, acidity reduced, the color turned to be yellow, hardness decreased, and it fully show the specialty of the apple good quality. Further storage, the apples will become soft texture, brittle, juicy, and then decline, deterioration, rot because of consumption of nutrients within the fruit.Apple varieties from the world: Champion, Gala, Golden Delicious, Red Delicious, Idared, Red Jonaprince, Ligol, Jonagored, Najdared, Gloster, Fuji, Pink Lady, Granny Smith, JazzTM.
Most of these apples can be stored in the cold room and treat with 1-MCP to extend the shelf life.
2.Note of picking
Apple collection time affects yield and quality. If pick up too early, fruit development is not complete with slight weight, poor appearance color, low sugar content and no good quality. If pick up too late, flash become soft fast and disease resistance is low, then the apples will be not suitable for storage.
2.1 Suitable harvest period
2.1.1 Appearance including fruit size, shape, color and so on can achieve the inherent traits of the apples. The seeds are black and the fruit powder is matured.
2.1.2 Fruit hardness should be 5.4～6.8kg/m2. The earlier ripen, the lower hardness. Hardness of stored apples should be slightly more than that of apples for eating.
2.1.3 During the period of fruit growth, each cultivar has a relatively stable number of days from the flowering period to the mature stage. The early maturing varieties are from 100 to 110 days, the ripening varieties are 120 to 140 days, and the late mature varieties are 140 to 175 days. Fruit growth periods from different regions are different because of temperature difference, and the harvest period is also different. As per local habit harvesting period, the best picking time is ±10 days when the apples ripe completely.
2.2 Notion of picking process
Pick apples gently to avoid mechanical damage.
20 days before picking, do not use nitrogen fertilizer, 5 days before picking, do not irrigate the orchard. Donot pick up when rain within 3 days or morning dew or fog. Best appropriate picking time is when morning dew has been dried, and the temperature is not high, or after 4 pm. After picking, the apples should be put in a dry and cool place.
3.Prepare before storage
Harvesting apple often maintain a high field of heat, breathing, metabolism and other physiological activities strong, easy spontaneous ripening. If put the apples in the cold room directly without pre-cooling, because of 20℃ temperature difference, fruit physical activity disorders and excessive cold injury, the apples will be heat rot and quality will be affected.
Put apples on the well ventilated, dry ground, low temperature indoor, or put in a shade place and cover them during the day and cool apples in the night.
3.2 Chamber management
Eliminate the odor and debris inside the store. Use Potassium permanganate or Sulfur to disinfect the cold room. Cool down temperature of the cold room to 0°C two days in advance, put the cooled apples in the cold room, keep gaps between apple stacks for ventilation. Adjust the temperature of chamber when finish storing all of the apples. Try to fill the chamber with fruits in 10 days, then treat them with 1-MCP in time.
4.1-MCP treatment on apples
When the cold room is full of apples, fumigate them with 1-MCP immediately, to prevent respiration peak, reduce respiratory strength, and inhibit ethylene. Then extend shelf life of apples and keep them fresh for long time.
5.1 Cold room control
CA storage: O2 2%~4%, CO2 1%~5%
Timely regulate the temperature and humidity of chamber, keep them stable. The temperature cannot be too low, otherwise the water will loss and fruits will be wilting, then the apples quality will be not good. Spray some water when the humidity is not enough. Defrost refrigeration storage to maintain constant temperature.
Sterilize cold storage per two weeks. Fungicide will be better when used in alternatively.
Ventilate every 15 days, ventilation time is about 30min, ventilation when weather is sun and outside temperature is low.
5.4 Out of stock
Warm the apples before out of the cold room, otherwise there will be condensate water on the apples, then apples will be rot easily.
6.Apple trees disease and control
For better apple quality, it is necessary to use some agrochemicals on apples trees. Captan can
To reduce storage disease, it is necessary to do a lot of pre-harvest work. Such as prevent and control the physiological diseases of apples.
Captan can control of apple rot disease, anthrax, brown spot, spotted leaf disease, coal pollution, scab, etc.
Prohexadione Calcium can help apple tree flowering, early yield and nutrient growth.