Temporal changes in Lycium barbarum fruit separation force and hardness during selective harvesting

Lycium barbarum, a plant belonging to the Solanaceae family, is widely used in China due to its abundant nutritional value. Although the current mechanized harvesting method of L. barbarum has effectively minimized production expenses, it continues to have the challenge of inconsistent quality of the produced L. barbarum. The objective of this paper is to evaluate the correlation of the separating force and hardness concerning the timing of harvesting, maturity, and variety. Thus, the optimal time for harvesting ripe L. barbarum can be determined to enhance the quality of selectively mechanized harvesting of this fruit. The experiment was conducted in a L. barbarum plantation located in Qinghai Province during the 2023 harvest period. Two occasions were studied focusing on the primary cultivars Ningqi No. 1 and Ningqi No. 7, examining the three ripening stages of L. barbarum harvested at various times throughout the day. The finding of this study showed that the separation force and hardness of L. barbarum fruits were influenced by the harvesting time, the fruit variety, and the level of maturity. The optimal timing for harvesting different types of L. barbarum varies. It was observed that Ningqi No.1 was best to be harvested in the late afternoon and evening (17:00-21:00), whereas Ningqi No.7 was most suitable to be harvested in the morning (7:00-9:00).