Evaluation of the bioformulation of potent strains of Trichoderma spp. and Pseudomonas spp. against Fusarial wilt of bottle gourd (Lagenaria siceraria)

摘要

Bottle gourd (Lagenaria siceraria L.) is an important vegetable crop belonging to the gourd group in cucurbitaceae family. The production and productivity of this vegetable crop is affected by many diseases, of which wilt (Fusarium oxysporum f.sp. lagenariae) plays a significant role. Among different management strategies available, biocontrol seems to be promising as the use of chemical fungicides in disease management has many limitations including fungicide resistance and environment hazards. Biological control can play an effective role in combating this problem by effectively managing the disease. Considering the importance of disease, the present study was conducted with an objective to evaluate the potential biocontrol agents against Fusarialwilt of bottle gourd. In this study, several isolates of Trichoderma and Pseudomonas were isolated from wilt affected bottle gourd growing regions of Punjab and were screened and later tested under in vitro and in vivo conditions to determine their antagonistic effect on Fusarium oxysporum f.sp. lagenariae. Dual culture and volatile assay showed that two isolates of Trichoderma (T1 and T2) and one Pseudomonas isolate (P1) had superior antagonistic potential, when tested under in vitro conditions. Of these potential isolates, Trichoderma isolate T2 showed maximum mycelial growth inhibition of Fusarium oxysporum f.sp. lagenariae (76.33) in dual culture. On the basis of molecular characterization, the potent isolates T1 and T2 were identified as Trichoderma asperellum and isolate P1 was identified as Pseudomonas aeruginosa. The potent bioagents (T1, T2 and P1) were then evaluated for their bioefficacy under in vivo conditions for two growing seasons in year 2018-19. Maximum disease inhibition 84.62 and80.00 was reported by Trichoderma asperellum isolate T2 in March and June sown bottle gourd crop, respectively. Besides, Trichoderma asperellum (T2) exhibited highest plant growth promotion with total length (5.43m and 4.83m) alongwith enhanced yield i.e. 235.99 q/acre and 229.00 q/acre in March June seasons, respectively. Based on the findings, the biocontrol agents viz. Trichoderma asperellum (T2 and T2) and Pseudomonas aeruginosa (P1) have greater potential in managing wilt of bottle gourd and their bioformulations can be used at commercial scale to manage the disease at farmer’s field.