Strawberry cultivation under open-field, raised-bed, or tabletop polyhouse systems is highly vulnerable to destructive fungal pathogens. Gray mold (Botrytis cinerea) poses the greatest threat during flowering and fruiting, while powdery mildew (Podosphaera aphanis) and soil-borne root rots (Rhizoctonia, Pythium, Phytophthora) cause crown collapse and yield reduction. Applying Bacillus subtilis as a runner root dip, drip drench, or foliar spray introduces a protective microbial layer across flowers, leaves, and berry surfaces. The bacteria colonize host tissues and secrete cyclic lipopeptides (surfactin, iturin, fengycin) that disrupt fungal spore germination and cell wall integrity.

Beyond disease suppression, Bacillus subtilis acts as an effective plant growth-promoting rhizobacterium (PGPR) in high-density strawberry systems. It solubilizes fixed soil phosphorus, chelates micro-nutrients via siderophore secretion, and stimulates adventitious root formation in newly planted runners. Regular application maintains a clean rhizosphere, supports uniform flowering flushes, and increases total soluble solids (Brix) in developing berries. Because Bacillus subtilis leaves zero toxic chemical residues, it allows harvests right up to the day of picking (zero-day Pre-Harvest Interval), meeting strict organic and export standards while extending post-harvest shelf life.

Importance of Bacillus subtilis in Strawberry Cultivation

Strawberry has a shallow root system that is highly vulnerable to soil-borne diseases and environmental stress. Healthy roots are essential for continuous nutrient uptake, flower production, berry development, and fruit quality.

Bacillus subtilis rapidly colonizes the rhizosphere and competes with harmful microorganisms for nutrients and space. It also produces natural antimicrobial compounds that suppress disease-causing fungi and bacteria while promoting beneficial microbial activity.

Healthy roots enable vigorous vegetative growth, continuous flowering, better fruit set, and production of premium-quality berries.