Enhanced flowering and honey production potential in jujube (Zizyphus jujuba Miller var. inermis Rehder) trees using Bacillus velezensis CE 100

Jujube honey, enriched with minerals and bioactive phenolic compounds, is highly valued by consumers and commands a premium price, enhancing beekeeper income. As nectar is the primary raw material for honey, increasing nectar-producing flower resources is essential. While chemical fertilizers can boost floral resources in the short term, their prolonged use may lead to reduced soil organic matter, disrupted soil structure, and environmental pollution. This study evaluated the potential of Bacillus velezensis CE 100 to enhance vegetative and reproductive growth in jujube trees through nitrogen fixation, phosphate solubilization, and phytohormone production. The bacterium exhibited nitrogen fixation and phosphate solubilization abilities and produced indole-3-acetic acid, which promotes root development. These functions improved nutrient availability and uptake, leading to a higher chlorophyll index and more bearing shoots per tree, representing 1.3- and 1.1-fold, and 1.2- and 1.1-fold increases compared to the control and chemical fertilizer treatments, respectively. Additionally, the bacterium produced gibberellic acid, a phytohormone associated with floral induction and development. The application of B. velezensis CE 100 to jujube trees elevated the total number of flowers per tree and the flowering period by 1.7- and 1.4-fold, and by 1.6- and 1.4-fold, compared to the control and chemical fertilizer treatments, respectively. As a result, potential estimated honey production per tree reached 853.32 mg, representing 1.8- and 1.4-fold increases compared to the control and chemical fertilizer treatments, respectively. These findings suggest that B. velezensis CE 100 has the potential to improve floral resource productivity and estimated honey production from jujube. Nevertheless, further multi-annual field evaluations are required to substantiate its long-term applicability and sustainability under varying cultivation conditions.