Vol. 9, Issue 4 (2020)

Author(s):
HS Viswanath, Roaf Ahmad Rather, KA Bhat and SH Peerzada

Abstract:
Bacterial soft rot is one of the most destructive diseases worldwide causing heavy losses in field, storage and transit. Chemical control of this disease was not successful even in developed countries besides use of antibiotics to control this disease on stored produce causes severe health complications by inducing resistance to other human pathogenic bacteria. In present study, four different bacterial species viz., Bacillus subtilis, Pseudomona fluorescens, Bacillus tequilensis and Bacillus spp. were evaluated against Pectobacterium carotovorum, soft rot causing pathogen in-vitro. Best results were obtained by Bacillus subtilis with a mean diameter zone of inhibition of 14.33mm followed by Pseudomonas fluorescens with a zone 0f 14mm. Least zone of inhibition of 2.16mm was observed in case of Bacillus sp., whereas no zone of inhibition was observed in case of both control (sterile water) and Bacillus tequilensis. The two effective antagonists in vitro viz., Bacillus subtilis and Pseudomonas fluorescens were also evaluated against post-harvest soft rot disease on potato tubers at different times viz., 12 hours prior to the inoculation, simultaneously with the inoculation of the pathogen and 12 hours after the inoculation of the pathogen. Among the bio-agents evaluated, Bacillus subtilis exhibited highest control with the disease incidence of 84% and severity of 16.8% followed by Pseudomonas fluorescens with the incidence of 88% and severity of 17.6% when applied 12 hours prior to the inoculation of the pathogen even after 6 days of storage.