Key Points of Harvesting and Storage Techniques for Pomegranate Cultivation
The signs that a pomegranate fruit is ripe are: the fruit ridges become visible, the rind turns from green to yellow, and the fruit surface becomes glossy. The red or silvery-white needle-like crystals in the flesh cells become fully visible. In northern production areas, the period from the Autumn Equinox to Cold Dew is the suitable harvest time. Picking too early results in poor flavor and poor storage tolerance. For pomegranates in the south, the first-bloom fruits and large fruits should be picked first, and the later-ripening ones picked afterward.
When picking, diseased fruits and cracked fruits should be picked by specially assigned personnel and handled in a centralized way to prevent the spread and transmission of disease. When picking on rainy days, water easily accumulates in the calyx tube of the fruit, which readily invites pathogen invasion and causes rot; therefore, picking should be done on sunny days. When harvesting, support the branch with one hand and pick the fruit with the other, picking and placing gently to prevent mechanical damage to the pomegranate fruits. When fruits are squeezed and internal injury occurs, it cannot be seen from the outside, but during storage and transport, the juice that leaks out from the broken ones will affect the other unbroken seeds and cause them to deteriorate.
Late-maturing varieties store better. Varieties with good storage tolerance include: Shaanxi's Dahongtian, Jingpitian, Tianhongdan, and Sanbaitian pomegranates; Shandong's Qingpitian, Damayatian, Dahongpisuang, Yuhuangdian pomegranate, Qingpisuang, Gangliutian, and Mayasuan; Shanxi's Qingpitian and Shuijing Jiangmalius; Yunnan's Jiangyi pomegranate, Tongke pomegranate, and Qingke pomegranate; Sichuan's Daqingpi pomegranate; Guangdong's Shenwo pomegranate, and so on. Varieties that do not store well include Anhui's Yushizi pomegranate, Yunnan Mengzi's sweet pomegranate, and so on.
After the fruits are harvested, diseased, damaged, and cracked fruits should be removed, and fruits that may have internal injury should also be picked out early and sold immediately. For sound, undamaged fruits, grade them according to individual fruit weight, to be supplied respectively for foreign trade, out-of-town shipment, and nearby sales as processing raw materials.
Using Zaopi pomegranate preservative No. 2 at 1000 times dilution, 50% carbendazim at 1000 times dilution, or 45% carbendazim suspension concentrate at 800 times to 1000 times dilution, soak the fruits for 3 minutes to 5 minutes; after drying, the pomegranates can be stored. When the storage quantity is large, the above agents can be sprayed onto the fruit surfaces, and after drying they can be stored.
Pomegranates like warmth, and the basic requirement for their storage is suitable temperature and high humidity. 0°C will cause chilling injury; the suitable temperature is 4°C to 5°C.
For fruits used for hanging storage, a section of fruit stalk should be retained at harvest, tied into bunches with thin string, and hung in a cool room; or the fruits can be wrapped in newspaper or plastic film and hung in a room with relatively small temperature and humidity changes, where they can be stored until around the Spring Festival.
New earthen jars or vats and crocks can also be used. Spread a layer of fine sand or wheat straw about 5cm thick on the bottom, place pomegranates that have been pre-stored in a cool, ventilated place for three days (the pomegranates have already been treated with fungicide before pre-storage) into the container in layers until it is full. Seal the jar mouth or vat mouth with plastic film and tie it tightly, then check once a month; if there are rotten fruits, remove them promptly. This method can store them until April of the following year.
Place pomegranates that have been pre-cooled and treated with fungicide into polyethylene plastic film bags, tie the bag mouths well, and place them in a cool room, where they can be stored for 140 days, and the pomegranate fruits will still be as fresh as ever. Pomegranate fruits treated with fungicide can also be individually wrapped in plastic bags; stored under conditions of 3°C to 4°C for 100 days, the seeds retain good freshness.
On a floor slab or earthen upper floor unaffected by smoke and dust, first spread a layer of fresh green masson pine needles on the floor or at the bottom of a cabinet, place a layer of pomegranates, then spread another layer of pine needles. In this way, store them in alternating layers of fruit and pine needles, cover the top of the pile with pine branches, rice straw, and other coverings, turn and inspect the pile once every half month, remove rotten fruits, and replace the pine needles once. Storage-tolerant varieties can be stored until April or May of the following year using this pile-storage method. Note that before pile-storing the fruits, the fruit rinds must first be washed clean with clean water and pre-cooled.