Mango orchards face significant economic risks from panicle and fruit diseases, primarily anthracnose (Colletotrichum gloeosporioides), powdery mildew (Oidium mangiferae), and bacterial canker (Xanthomonas citri pv. mangiferaeindicae). High humidity during flowering and fruit set accelerates spore movement, causing blossom blight and latent fruit decay. Applying Bacillus subtilis as a pre-flowering and fruit-development foliar spray establishes a dense population of antagonist bacteria over leaves, inflorescences, and developing mango rinds. The bacteria secrete natural antifungal lipopeptides (iturins, fengycins) and antibacterial metabolites that prevent spore germination and block fungal hyphae from establishing latent infections.

Beyond disease control, Bacillus subtilis acts as a beneficial plant growth-promoting rhizobacterium (PGPR) in perennial tree crops. When applied through drip irrigation or soil drenching around the feeder root zone, it solubilizes fixed soil phosphorus, mobilizes micronutrients, and synthesizes natural growth signals. This root-zone activation enhances panicle emergence, improves flower retention, and minimizes physiological fruit drop. Integrating Bacillus subtilis into annual orchard management schedules produces clean, unblemished fruit with excellent rind color and extended post-harvest shelf life suitable for long-distance transport and export markets.

Importance of Bacillus subtilis in Mango Cultivation

Mango is a perennial fruit tree that remains productive for several decades. A healthy root system is essential for continuous nutrient uptake, canopy development, flowering, and fruit production. Soil-borne diseases gradually weaken root systems, resulting in poor vegetative growth, irregular flowering, fruit drop, and declining orchard performance.

Bacillus subtilis rapidly colonizes the root zone, competing with disease-causing microorganisms for nutrients and space. It produces antimicrobial metabolites that suppress harmful fungi and bacteria while supporting beneficial microbial populations.

Healthy roots improve nutrient absorption, enhance water-use efficiency, strengthen canopy growth, and enable consistent production of high-quality fruits.