Evaluation of different fungicides and antagonists In vitro and In vivo condition against Alternaria blight of pigeonpea

Abstract

Efficacy of bio agents and systemic and non-systemic fungicides @ 50, 100, 200, 250 and 500 ppm were evaluated In vitro against Alternaria tenuissima causing Alternaria blight of pigeonpea. The relative efficacy of bio agents were studied in dual culture plate method showed that Hypocrea rufa was found most effective antagonist against test pathogen followed by T. harzianum. Efficacy of six fungicides was tested in poisoned food technique. Among the six fungicides tested, mancozeb was found most effective against test pathogen followed by Chlorothalonil and Iprodione. Propineb was least effective against mycelial growth of test pathogen. Raise in concentration of fungicides was more effective in inhibiting the mycelial growth of the pathogen. Field condition studies were found out to be the effect of seed treatment, foliar spray, seed treatment+ foliar spray with six fungicides and two bio agents and their combination used as against pathogen. Artificial inoculation of mass culture of A. tenuissima was done in the inoculated seed treatment and after foliar spray on the plants sixty DAS. Amongst them twenty five treatments, combination of Mancozeb with H. rufa was found most effective in reducing the disease intensity and disease control followed by Mancozeb with T. harzianum and Mancozeb alone, respectively. While, T. harzianum alone was least effective and maximum disease intensity recorded as a compared to control followed by T. harzianum with double dose and T. harzianum and H. rufa combination treatment, respectively. In case of both seed treatment and foliar spray of Mancozeb with H. rufa was found most effective in reducing the disease intensity and disease control followed by combination of Mancozeb with T. harzianum and Mancozeb alone, respectively. Whereas, least effective and maximum disease intensity and disease control were observed T. harzianum alone as compared to control.