Harvesting technologies for Chinese jujube fruits: A review

In this article, a review of the mechanisms that have been developed to improve the efficiency of Chinese jujube (Ziziphus Jujuba Mill) was made. This fruit is considered as an economic crop in the arid and semiarid regions especially in China, where the cultivation methods alternate between traditional and intensive. In the former the trees are large and planted with relatively wide space, whereas in the latter the trees are dwarfed with tight spacing among them. Mechanisms which were studied and tested, for each cultivation method, were summarized and compared in terms of fruit collecting efficiency and rate of damage. These mechanisms were branch beating, trunk shaking, air shaking for traditional cultivation and tree shaking, canopy shaking, and vacuum suction for intensive cultivation. The comparison indicated that as the efficiency increase for any single mechanism the rate of damage increases accordingly. Therefore, a combination of mechanism would maintain the efficiency and reduce damage. In particular, a combination of a mechanism of tree shaking, developed earlier for blueberry, and trunk shaking was thought to be with high potential of low rate of damage. This article also spots on the possibilities of fully automating the post-harvest operation of fruit grading by describing a number of previous articles that have tackled fruit sorting not only for fruit processing but also for fresh market. The hope is that this review will spark the renewal of research and development of the cultivation of Chinese jujube so as to meet the increasing demand.