Effect of fungicides, plant extracts / botanicals and bioagents against damping off in brinjal

Brinjal damping off incited by Pythium ultimum Trow. is one of the most important and destructive disease of brinjal, which can cause mortality upto 90% (pre -emergence seed rot and post emergence seedling mortality). Being soil borne, P. ultimum is very difficult to manage with fungicides alone and also uneconomical. Therefore, the present in vitro studies were undertaken to test bioefficacy of the nine fungicides (each at 500, 1000 and 1500 ppm), ten plant extracts / botanicals (each at 10, 15 and 20 %) and seven bioagents against P. ultimum. The experiments were designed with CRD and all the treatments replicated thrice. Results reveal that all the fungicides, botanicals and bioagents tested were found effective and were fungistatic against the test pathogen and significantly inhibited its growth over untreated control. Of the fungicides tested, Metalaxyl was found most effective and recorded 84.22% mean growth inhibition of the test pathogen. The second and third best fungicides found were Captan + metalaxyl and carbendazim + Mancozeb with mean growth inhibition of 82.42 and 62.88%, respectively. The rest of the fungicides tested recorded mean growth inhibition in the range of 24.50 to 52.79%. Of the botanicals evaluated, garlic was found most effective and recorded significantly the highest mean mycelial growth inhibition (94.83%). The second and third best botanicals found effective were Adulsa (75.53 %) and Datura (60.65 %). The rest of the botanicals tested recorded mean growth inhibition in the range of 20.82 to 56.83%. Of the bio-agents evaluated, Trichoderma viride was found most effective and recorded significantly highest mean mycelial growth inhibition (69.44%). The second and third best bioagents found effective were Trichoderma koningii (67.32%) and Trichoderma hamatum (63.99%); the rest of the bioagents also recorded significant inhibition of the test pathogen. Results reveals that seed treatment of captan (at 1.5 g/kg) + metalaxyl (at 3g/kg seed)+ garlic extract (at 100ml/kg soil) +soil application of T. viride (at 25g/kg soil) was the most effective treatment which could be practiced on large scale for management of damping off disease in brinjal and other solanaceous vegetable crops. Key words: Pythium ultimum, plant extracts/ botanicals, bioagents, fungicides, Brinjal.