“+Double Fresh” “1-MCP” preservative will control all kinds of physiological and biochemical response, such as the release of ethylene, respiratory intensity etc., which may occur after the harvest of apple; inhibit the dematuration of endogenous-ethylene and exogenous-ethylene; slow down the progress of mature and senescence of apple; extend the storing period of apple; preserve fruit’s hardness, fracturability, nutritional content, and water content of the apple fruit, and the surface color of apple; and prevent physiological diseases during the storage period of apple fruit.

     I. Apple Varieties and Storage Characteristics：

       Apple is a kind of typical climacteric fruit. Its after-ripening is very obvious after being harvest, the starch in apple fruit will convert into fructose; the acidity will be lowered; the color of fruit will turn yellow from green; the hardness will be lowered; the fruit will show off its color, gust and aroma that is peculiar to this variety of apple, and the best edible quality of this variety can be achieved. If the storage period of apple is being extended longer, the fruit will turn soft, lose crisp with less juicy because of the large wastage of the nourishing substances in fruit, and it may be decayed, deteriorated and rot further.

     There are many apple varieties in China, and they can be classified into three varieties as early maturing variety, medium variety and late maturing variety.

1. Early mature varieties: The maturation period is from June to early July. The main varieties are Liaofu, Fushuai, Sweet Huangkui, Huangkui, Hongkui, Zhuguang, Danding, Fuhuapi,etc. Because of the shorter growing period, the flesh tissue is not compact enough and the flesh is soft, and also bland in taste, easy to decay, and hard to be storage. For all these reasons, the apples are always directly put into the market for fresh sales or short-term storage, without long term storage.

2. Medium varieties: The maturation period is from August to September. The main varieties are Golden Delicious, Delicious, Starking, Shouhong, Kuihong, Huaguan, Fujin, New GALA, Jonathan etc. These varieties of apple’s storage characteristics are better than the early mature variety. However, they are hard to be stored for a long term under the primitive storage conditions. The storage period can be extended to January or March of the next year by using cold storage and controlled atmosphere storage if the mechanical refrigeration method is adopted.

3. Late mature varieties: The maturation period is from October to November. The main varieties are Ralls Janet，Qingxiangjiao, Wojin, Fuji, Nagafu 2, Qiufu 1, Jigan, etc. These varieties of apple are high yield for endurable storage. Late mature varieties are the main varieties for storage. 

II. Harvest and Notes:
        The time of harvest will affect apples’ yield, quality and storage characteristics directly. If being harvested early, stunted fruits are light, with poor surface color, low sugar content and poor quality; if being harvested late, the flesh will turn soft soon and cannot be stored for a long term because of the poor capability of disease-resistant. Only if being harvested timely, will the edible quality of fruit be the best, the storage period be the longest, and the highest benefit can be gained.

1. Suitable harvest period is mainly determined according to the following aspects:

(1) External appearance includes the fruit size, shape, color and so on, and all these have reached the intrinsic appearance of the variety. Seeds turn black, and powder is formed mature.

(2)Interior index  The fruit hardness is usually between 5.4 to 6.8 kg/m2, the sooner the fruit mature, the lower the hardness will be. The hardness of storage fruit should be higher than that of marketing fresh; The content of solid is 12% ~ 15%, the percentage will be higher with the delay of mature stage.

(3) Growth stage of fruit   Every variety has a relatively stable number of days from the full- bloom stage to the mature stage. The days of early maturing variety is 100~110 days, the days of medium variety is 120~140 days, and the days of late mature variety is 140~175 days. Because of the different cumulative temperature of fruit growth stage in different areas, the harvest period will be different. The fruits in different areas should be harvested by stages in before and after 10 days of habitual harvest period.

2. Notes of harvesting:

(1) When harvesting the fruit, people should hold the fruit in hand, the index finger shall withhold the handle end of fruit and upturn gently, then the end of fruit will be separated from fruit spur. Please avoid dragging the fruit by main force; Move gently in order to prevent mechanical damage and avoid microbial invasion from the wound infection disease.

(2) The picking sequence is first canopy and lower, then inside and upper.

(3)Do not water in the 5 days before harvest; do not use nitrogen fertilizer in 20 days；do not harvest in the 3 days after raining or when there’s morning dew or fog. The harvest should do in the sunny day. It would be the best time to harvest when the morning dew disappears, the weather is not too hot or after 4 P.M. The harvested fruits should be stored at the shadow place.

III. Preparations before Storage:

1. Pre-cooling  Before being low temperature storage, apples should be pre-cooled, or the storage characteristics will be badly affected. Apples can often maintain high field heat when being harvest, and its respiration, metabolism and other physiological activities are very strong, so it’s easy to spontaneous ripening. Meanwhile, if the apples are stored into cold storage without pre-cooling, the 20℃ temperature difference between inside and outside of cold storage may lead to the disorder of physiological activity of fruit and extreme cold frostbite, and will condense on the surface of fruit, and it's easy to heat and rot. All these will affect the quality and short the storage period, so the apples must be pre-cooled. The pre-cooling process is putting the harvest fruit in the indoor or the shade of the tree under the circumstance of good ventilation, dying ground and low temperature.

2. Store management   Eliminate peculiar smell in the store, eliminate sundries in store. Close the door firmly for 24 hours after brushing the floor with a saturated solution of potassii permanganatis or chlorinated lime, or fumigate 48 hours with sulfur mixed with dry sawdust as 5~15g per cubic meter, then start cooling. The temperature of the disinfected cold storage should be lower to 0℃ two days before, then put the pre-cooled apples into the store. There should be enough room to ventilate easily between cases, stacks in the apple stacks, the apple stacks around, and also between the apple stacks. After all the storage work is finished, please adjust the temperature in the store. Additionally, the storage work should be finished in 10 days or so, and carry out the preservation process timely.

IV. “+Double Fresh” “1-MCP” Preservation Process:

 After all the storage work is finished, the apples should be fumigated by “1-MCP” preservative timely so as to prevent apples’ climacteric rise, lower the respiration intensity, and inhibit the release of ethylene, then extend the storage period and shelf life of apples effectively. “1-MCP” preservation will highly reduce the percentage of superficial scald occurred during the storage period.

V. Storage Management:

1. Proper storage conditions:

Temperature: -1℃～1℃

Relative humidity: 85%~ 95%

Controlled atmosphere conditions: O2:2%~4%   CO2:1%~5%

During the storage period, the temperature and humidity of the store should be regular checked so as to keep the temperature and humidity being stable, as the frequently changes of the temperature and humidity may have deadly harm on apples. The humidity should not be too low, in case the wilting or water loss may affect the fruit quality. If the humidity of the store is not enough, please water the store. Timely defrost to maintain the constant temperature.

2. Disinfection: Timely disinfect during the storage period, disinfection semimonthly would be the best, and the fungicides should be changed frequently to get the better effect.

3. Ventilation: During the storage period, ventilate in time to exhaust the bad gas so as to avoid the occurrence of other physiological diseases. The ventilation should be done every 15 days or so, and half hour around for every time, and please choose the sunny day with low temperature for ventilation.

 4. The delivery from storage to market: The apples shall be warmed gradually before the delivery from storage, or condensed water will be on the surface of apples after the delivery from storage, and this may accelerate the rot of apples.

VI. Storage diseases and Prevention:
        For many physiological diseases, measures should be taken before harvest so as to reduce the occurrence of diseases in the storage period, so it’s the indispensable work to strengthen the management of store. To spray pesticides in the flowering may protect apples from apple mouldy core and core rot. To spray 0.5% calcium chloride in the mid and the late of the fruit development period may control apple bitter rot. To spray 0.3% calcium nitrate to canopy and fruit two to four times from August to September may protect apples from lenticel blotch pit effectively.