In vitro evaluation of botanical extracts and fungicides against phytophthorablight of chili pepper (Capsicum annum L.).
Recently, an increasing interest has been observed in utilization of botanicals to manage phytopathogenic fungi. An investigation was undertaken to evaluate six different aqueous botanical extracts in vitro for their antifungal activity against Phytophthora capsici associated with chili blight. Aqueous botanical extracts of Parthenium hysterophorus revealed promising antifungal activity against the pathogen and exhibited up to 100% inhibition compared to control. While, aqueous extracts of Azadirachta indica, Calotropis gigantea, Cassia fistula, Nerium oleander and Oscimum basilicum were not effective against the pathogen. Instead, they revealed a stimulatory effect on colony growth of the pathogen with negative values of percent inhibition. Cassia fistula had the most stimulatory effect on colony growth of the pathogen. Three different fungicides Ridomil (Metalaxyl+Mancozeb), Curzate (Cymoxanil+Mancozeb) and Proctor (Difenconazole) were also tested in vitro at three different concentrations 50, 100 and 150 ppm against the colony growth of the pathogen. Ridomil and Proctor produced 100% inhibition of the pathogen at all tested concentrations followed by Curzate.