Efficacy of Pseudomonas fluorescens and Trichoderma asperellum against Fusarium Wilt of Cucumber in Semi-Arid Zone

Fusarium wilt, caused by Fusarium oxysporum f. sp. cucumerinum (FOC), poses a significant threat to cucumber (Cucumis sativus L.) cultivation, particularly under continuous cropping systems. In the present study, talc-based bioformulations of Pseudomonas fluorescens (Pf6) (OP002308) and Trichoderma asperellum (Th d) (OP012701) were developed and evaluated under polyhouse conditions for the management of Fusarium wilt (FOC, OP002306) in cucumber. The combined application of seed treatment and seedling dip with Pf6 significantly reduced wilt incidence (2.5%) compared to the control (25%) and outperformed chemical fungicide (Carbendazim 50% WP). Pf6 also enhanced crop earliness and recorded the highest yield (129.98 q/ha). Rhizosphere competency studies revealed that Pf6 maintained higher colony-forming units (CFU/g) over time compared to Th d, indicating superior root colonization. The biocontrol efficacy is attributed to mechanisms such as competition, antibiosis, and induction of systemic resistance. These findings establish P. fluorescensPf6 as a promising, eco-friendly alternative for managing Fusarium wilt and enhancing productivity in cucumber cultivation under protected conditions.