Chrysanthemum (Chrysanthemum spp.) crops experience heavy foliage defoliation and flower stem decline from airborne and soil-borne fungal pathogens, notably White Rust (Puccinia horiana), Septoria Leaf Spot (Septoria chrysanthemella), and Fusarium Wilt (Fusarium oxysporum f. sp. chrysanthemi). White rust produces raised pinkish-white pustules on leaf undersides, spreading rapidly in humid greenhouses and causing leaf cupping and death. Applying Bacillus subtilis as a cutting dip, soil drench, or foliar spray establishes a defensive biological layer over leaves, stems, and root zones. The bacteria colonize tissue surfaces, producing cyclic lipopeptides (surfactin, iturin, fengycin) that disrupt fungal spore germination and inhibit hyphal growth.

Beyond disease control, Bacillus subtilis serves as an efficient plant growth-promoting rhizobacterium (PGPR) in commercial flower crops. It solubilizes fixed soil phosphorus, secretes siderophores for iron mobilization, and produces growth regulators that encourage lateral branching and root development. Enhanced root health supports dense canopy formation, increases bloom count per spray, and maintains dark green leaf health. Regular application ensures clean, unblemished cut and potted chrysanthemums with extended vase life.

Importance of Bacillus subtilis in Chrysanthemum Cultivation

Chrysanthemum requires a healthy and active root system to sustain vigorous branching and prolonged flowering. Strong roots ensure continuous uptake of nutrients required for producing uniform, high-quality flowers throughout the production season.

Bacillus subtilis rapidly colonizes the rhizosphere and competes with harmful fungi and bacteria for nutrients and space. It also produces natural antimicrobial metabolites that suppress disease-causing pathogens while encouraging beneficial microbial populations.

Healthy roots support more flowering shoots, better bud initiation, larger flowers, and higher marketable flower yield.