1. Harvest in a timely manner
The golden pears in North China were harvested in time from September 20 to 30. At this time, the fruit has matured, the accumulation of nutrients is sufficient, and the storability is optimal. Early harvest (September 10) pear fruit has a high rot rate throughout the storage period, and the peel is very easy to brown. It was harvested too late (early October), and brown scalding occurred more seriously in storage (18.94%). Special care should be taken during the harvesting process to avoid bruises.
2. Grading
The purpose of fruit grading is to standardize the commodity of goods. The grading standards of Chinese pears are divided into 4 types: national standards, industry standards, local standards and enterprise standards. Golden pear grading is mainly hand-selected according to weight, and equipment such as large fruit selectors have not been applied for grading.
3. Packaging
It can be divided into outer packaging and inner packaging. The production of upper and outer packaging are packed in cartons, 15-20kg per carton, carton requirements scientific, strong, economical, moisture-proof, exquisite and light. Inner packaging is to package the fruit with packaging materials (such as cling paper, crisper bags, etc.). The test has proved that the use of 0.013mm thick polyethylene film bag single fruit closed packaging, its natural loss rate and decay rate are low, and the fresh-keeping effect is good. Although the thick film bag can reduce the natural loss rate, it is easy to cause physiological diseases such as black heart disease. Therefore, it is advocated that the golden pear fruit be directly packed with 0.013mm thick commercial plastic film bag single fruit after harvest, and then packed into a box.
4. Pre-cooling
Golden pears are harvested with high temperatures and storage temperatures, such as the use of natural cooling storage (cellar), golden pears can not be directly stored, but fully pre-cooled to quickly dissipate the field heat. Therefore, it is necessary to use low temperature as much as possible for pre-cooling, and pay attention to prevent sun and rain. The results show that the golden pear fruit can adapt to rapid pre-cooling after harvest. Therefore, the fruits can be directly put into low-temperature cold storage for pre-cooling after harvest.
5. Storage period management
(1) Disinfection and rodent pest control in the warehouse: Disinfection has a positive effect on reducing microbial infection and fruit rot in the storage of golden pears, and is also an important link in management measures. The storage should be cleaned and disinfected one month before the golden pears are stored (and after storage). Commonly used agents are sulfur, formaldehyde, bleaching powder and sodium hypochlorite. In addition, attention should also be paid to the prevention and control of rat infestation, plug the hole, and use rat traps, poisonous ear booby-traps and other methods for prevention and control after the fruit is put into storage.
(2) Stacking code: After the golden pear fruit is transported to the cold storage, the stacking in the warehouse should be neatly arranged and firm, which is conducive to ventilation and management, and can make full use of the space. The bottom of the stack is cushioned with sleepers, and there should be appropriate gaps (usually 2-5cm) between each fruit box. The stacking height is determined by the compression strength of the box, but generally the upper part of the stack should leave a gap of about 60cm from the top of the warehouse. There should be gaps (generally about 30cm) between the stack and the wall, air intake holes, etc., and leave a sidewalk. Stacking can take the form of "pin-shape", "tic-tac-toe" and so on.
(3) Temperature: In order to better grasp the temperature of each part of the library, thermometers should be placed in different representative places. During storage, try to keep the storage temperature stable as possible to reduce large fluctuations in temperature, and the suitable storage temperature of golden pears is 0-2 °C.
(4) Humidity: The relative humidity of golden pears should be maintained at 85%-90% during storage. When the humidity in the warehouse is too high, dry sawdust or quicklime can be placed; When the humidity is low, it can be properly sprinkled with water, wet sawdust or wet straw curtain.
(5) Gas composition: When using modified atmosphere storage, we must pay attention to controlling O2 and CO2 concentration. The use of 0.01-0.02mm thick polyethylene film bag single fruit closed packaging, will not occur black skin and CO2 poisoning, with a very ideal storage effect.
(6) Proper ventilation: Golden pears should have sufficient ventilation during storage. Ventilation can take away the heat load in the warehouse, eliminate harmful gases such as ethylene, ethanol and CO2 produced during the physiological metabolism of the fruit, supplement appropriate oxygen, and prevent uneven temperature in the warehouse. In order to prevent large fluctuations in the temperature in the warehouse, ventilation should be carried out at the smallest temperature difference between inside and outside the warehouse.
