Management of Fusarium wilt with the use of potential bioagents in muskmelon

Muskmelon wilt caused by Fusarium oxysporum f.sp. melonis is a serious problem in muskmelon growing areas of Punjab. Soil samples from muskmelon fields were collected and analyzed for antagonistic microflora. In Kapurthala-Hoshiarpur region 58.33, 41.66 and 16.66 per cent of the samples showed the presence of Pseudomonasfluorescens, Trichoderma harzianum and Tricoderma viride, respectively. Similarly from Jalandhar-Ludhiana region 65.21, 60.86 and 26.08 per cent of the samples showed the presence of P. fluorescens, T. harzianum and T. viride, respectively. P. fluorescens(Pf11) and T. viride (Tv1) isolates produced largest inhibition zones 0.8 cm and 0.6 cm, respectively. Out of 19 isolates of T. harzianum, tested against Fusarium oxysporum f.sp. melonis, the growth of pathogen was least (2.2 cm) in presence of Th3 isolate as compared to 7.4 cm in the control. Per-cent growth inhibition of Fusarium oxysporum f.sp. melonis in presence of Th3 isolate of T. harzianum was maximum (70.2%). Six isolates of Trichoderma harzianum (Th3, Th13, Th11, Th17, Th19 and Th8), one isolate of Trichoderma viride (Tv1) and three isolates of Pseudomonas fluorescens (Pf10, Pf11 and Pf12) which showed maximum inhibition against pathogen in dual culture, were selected. Efficacy of talc based bioformulations of T. harzianum, T. viride and P. fluorescens isolates as seed dresser was observed against the muskmelon wilt under field conditions. Trichoderma harzianum isolate Th3 was the best with respect to per cent seed germination and wilt control. In addition, the same isolate of T. harzianum (Th3) followed by Pseudomonas fluorescens isolate (Pf12) promoted the growth of muskmelon plant in the seed treatment.