Evaluation of Substrates for Mass Production of Trichoderma harzianum and its Compatibility with Chlorpyrifos + Cypermethrin

Abstract

Coir pith compost, rice husk and sugarcane bagasse with and without 5% Jaggery solution as nutritional supplement was evaluated for the mass production of Trichoderma harzianumin comparison with coffee husk (parchment).On incubation up to 60 days, maximum number of propagules were recorded in coir pith compost (43 × 1010), coir pith compost + 5% jaggery (32.33 × 1010) and sugarcane bagasse (21 × 1010) followed by rice husk (38 × 1010) and rice husk + 5% jaggery (23.33 × 1010).Coir pith compost and sugarcane bagasse recorded more population than other substrates and hence could be used in mass production.In another experiment, the compatibility of T. harzianumand insecticide combination, Chlorpyrifos 50% + Cypermethrin 5% was studied by poisoned food technique on PDA medium at concentrations of 55, 83, 110, 138, 165, 193 and 220 ppm.In the first set, the insecticide was added to the autoclaved medium (hence not heated) and in the second set the insecticide was autoclaved along with the medium.In both the cases, the colony growth was very slow initially for 5 days, however continued to grow as evident from the measurements on 10th and15th day.Thus the insecticide was partially compatible with T. harzianumin in-vitrostudies at all the concentration levels.Later, T. harzianumand Chlorpyrifos + Cypermethrin were incorporated into soil taken in containers so as to get the above insecticide concentrations and studied the compatibility by monitoring the population by serial dilution plate technique.After 30 days, it was found that the propagules in all the insecticide concentrations were on par with each other.Hence it is implied thatthe insecticide did not affect the population of T. harzianumin in-vivoconditions and found compatible for field application