Insect Pollination Enhances Yield and Physicochemical Quality Traits in Three Jujube Cultivars

Jujube (Ziziphus mauritiana Lam.) is a nutritionally rich tropical fruit which is native to South Asia. In Pakistan, there are 50 varieties of jujube, and approximately 24,000 tons of jujube is harvested annually from a growing area of nearly 5000 hectares. The current study was conducted to investigate whether insect pollination affects fruit yield, and whether it influences the physical and biochemical properties of the fruit. We selected fifty inflorescences from each of the three jujube cultivars (Kheri, Desi, Ayuba) and covered them with muslin cloth to promote self-pollination. The same number was tagged to observe the impact of open pollination. Fruits from both treatments were counted on each panicle, harvested, and then subjected to lab investigation for measuring physical (fruit length, fruit width, fruit weight, and pulp weight) and biochemical (total soluble solids, titratable acidity, vitamin C, and pH) parameters. A diverse range of floral visitors, including bees, flies, wasps, moths, and butterflies, were observed on jujube, with bees being the most abundant functional group. Open pollination increased fruit set (fruits per inflorescence) by 2.3-2.5 times compared to self-pollination. Similar trends were observed in physical parameters: fruit length (1.15 to 1.30 times increase), fruit width (1.15 to 1.21 times), total weight (1.60 to 1.74 times), and pulp weight (1.55 to 1.62 times). Changes in physiological parameters, including pH, vitamin C, titratable acidity, and total soluble solids, were also observed in pollination treatments of all three varieties. Open-pollinated fruit also exhibited greater length and width, but lower firmness. These findings show the vital role of insect-mediated pollination in enhancing both the yield and quality of jujube fruit, with consistent benefits observed across multiple varieties.