Vol. 10, Issue 5 (2021)

Author(s):
Akash Babu M, MR Ravikumar and K Dinesh

Abstract:
In vitro evaluation of eight different chemicals and their combination viz. Copper oxychloride, Bleaching powder, Streptocycline + Copper oxychloride, K-cycline+ Copper oxychloride, Bacteriomycin+ Copper oxychloride, Streptocycline + Copper oxychloride + Bleaching powder, K-cycline + Copper oxychloride + Bleaching powder, Bacteriomycin + Copper oxychloride + Bleaching powder was carried out against Ralstonia solanacearum, among these Strptocycline (500 ppm) combined with Bleaching powder (3000 ppm) and Copper oxychloride(3000 ppm) showed best among all the treatments with mean inhibition zone of 26.66 mm and Bleaching powder alone had showed least mean inhibition zone of 10.33 mm. Six different antagonist organisms viz. Trichoderma harzianum, Pseudomonas fluorescens and Bacillus subtilis from Institute of Organic Farming, Dharwad (IOF Dharwad) and Trichoderma viridae, Pseudomonas fluorescens and Bacillus subtilis from local market were selected for in vitro evaluation. Among these Pseudomonas fluorescens of IOF Dharwad showed maximum inhibition zone of 15.33 mm, whereas Trichoderma viridae has no effect on the growth of test organism i.e., Ralstonia solanacearum. The anti-bacterial chemicals and bio-agents found effective under in vitro were evaluated under glass house. Among these Streptocycline 500 ppm + Copper oxychloride 3000 ppm + Bleaching powder 3000 ppm showed minimum per cent disease incidence with 16.66 per cent while Bacillus subtilis of local market was observed with maximum incidence of 61.11 per cent. The results supported that the use of antibiotics combined with Copper oxychloride and Bleaching powder was more effective and suitable than the other treatments for the management of bacterial wilt gherkins.