Detailed Explanation of Harvest Time and Methods for Jujube Fruit

The optimal harvest period is determined according to different varieties, consumption purposes, and processing methods. Harvesting of different varieties: For fresh-eating varieties such as Jin jujube, Xiang jujube, Li jujube, and Dong jujube, they are mostly harvested at the crisp-ripe stage. At this stage, the fruit has bright color, high sugar content, is sweet and sour, crisp and tender with abundant juice, and has good flavor, fully displaying the characteristics of fresh-eating varieties. If harvested too early, the skin is green, the flesh is hard, juice is scarce, and palatability is poor; if harvested too late, the flesh loses water and softens, the skin thickens, and the fresh-eating flavor is lost. For drying varieties, such as Hui jujube, Jixin jujube, Jinsi Xiaozao, etc., the full-ripe stage is the optimal harvest period. At this stage, the fruit is fully mature, nutrient accumulation is at its maximum, and dry matter content and drying rate are the highest. After drying, the color is rich and vivid, the fruit shape is plump, it is elastic, easy to store and transport, and of the best quality. If harvested too early, because the fruit is not yet mature, after drying the fruit is shriveled, the color turns yellowish, becoming "yellow-skin jujube," with inferior quality; if harvested too late, the flesh becomes saccharified, becoming "sugar-gourd jujube," which is difficult to dry and store. This shows that the consumption purposes of different varieties are closely related to the optimal harvest period. Different processing methods: For processing candied jujube and sugar jujube, harvesting at the white-ripe stage is appropriate. At this stage, the fruit has fully developed, the skin is thin, the flesh is loose, juice is scarce, sugar content is low, and it easily absorbs sugar liquid during sugar boiling. The processed product is crystal-clear, semi-transparent, has no skin residue when eaten, and is of good quality. For processing Wu jujube, Nan jujube, Yu jujube, Zui jujube, and syrup canned jujube, etc., harvesting at the crisp-ripe stage is appropriate. The color is dark purple and bright, the skin texture is fine, the flesh is firm, and the quality is premium. If the harvest period is inappropriate or too late, the flesh becomes spongy, there is little flesh and thick skin, the glossiness is poor, and the product yield decreases. Processing Zui jujube, syrup jujube, etc., can maintain the characteristics of fresh jujube, with crisp and tender flesh, juicy and refreshing, and unique flavor. Processing Yu jujube makes it easy to peel and pit. The finished product is sweet and rich, and highly popular. For processing jujube paste, jujube puree, jujube juice, etc., harvesting at the full-ripe stage is best. At this stage, the fruit is fully mature, the soluble solids content is the highest, and it is easy to pulp and congeal.

2. Harvesting methods Selective harvesting: Jujube trees have a long flowering period and easily set fruit continuously. Some varieties ripen at different times, so they are harvested in stages according to the ripening situation. In response to the shortcomings of "beating jujubes" which damages fruit and trees, for low-trunk short-canopy trees, large-fruit fresh-eating varieties, or special processing jujubes, manual picking can also be used to ensure harvest quality. However, manual picking efficiency is very low. Ethephon abscission method: Using ethephon for harvesting saves labor, time, and effort. In recent years, it has been trialed in some jujube-producing areas with good results. This method is mostly used 5-7 days before normal harvest, spraying the entire tree with a 150-250 mg/kg ethephon aqueous solution (calculated by volume of 40% ethephon stock solution). 3-5 days after spraying, the fruit stalks prematurely form an abscission layer, and with a light shake of the tree, all jujubes fall off, which can increase work efficiency by 8-10 times compared with general harvesting methods. For drying varieties, fruit prompted to fall by ethephon has low water content, short drying time, high maturity, purple-red skin with gloss, and can increase sugar content by 3%-5%, simultaneously serving to ripen, promote falling, and improve quality.

When using it, strictly control the spraying concentration, and as much as possible test first before applying, to ensure the effectiveness. Collection and Wax Sealing Treatment of Jujube Scions