In vitro Compatibility of Trichoderma and Bacillus biocontrol agents with Different Fungicides

Abstract

Biocontrol agents are beneficial for plant and soil health and are effective in controlling many plant diseases. These biocontrol agents in combination with fungicides at reduced doses can be more effective than using alone. Keeping this in view, an in vitro study was carried out to test the compatibility of commonly used fungicides viz., captan 50 WP, thiram 75% DS, tebuconazole 5.36% FS, carboxin 37.5% + thiram 37.5% DS, prochloraz 24.4% + tebuconazole 12.1% w/w EW and thiophanate methyl 450 g/l + pyraclostrobin 50 g/l with two fungal (Trichoderma asperellum and T.viride) and three bacterial biocontrol agents (Bacillus subtilis S4KB5, B. subtilis S8KB2 and B. subtilis B3). All the five fungicides were found to be compatible with all the biocontrol agents at 100ppm and 250ppm. All the fungicides except thiram, showed complete inhibition of T. asperellum at 1500ppm and 2000ppm and with T. viride, 100 per cent inhibition is shown by all the fungicides at 1500ppm and 2000ppm except carboxin + thiram. With biocontrol isolates, B. subtilis S4KB5, B. subtilis S8KB2 and B. subtilis B3, highest inhibition zone were recorded by prochloraz + tebuconazole (2000ppm), tebuconazole (2000ppm) and thiophanate methyl + pyraclostrobin (2000ppm). Present findings suggest that compatible fungicides can be used with biocontrol agents in an integrated disease management practices for the control of seed and soil borne pathogens.