In vitro evaluation of botanicals against Alternaria alternata (fr.) keissl., causing alternaria leaf spot of niger (Guizotia abyssinica (L.F.) cass.)

Niger (Guizotia abyssinica (L.f.) Cass.), a minor oilseed crop suffers from substantial damage due to leaf spot disease incited by Alternaria alternata (Fr.) Keissl. Results of the in vitro evaluation of various botanicals against A. alternata revealed that all the test botanicals significantly inhibited mycelial growth of A. alternata, over untreated control. Aqueous extracts of all the botanicals tested (@ 10%) were antifungal to the test pathogen. Among the effective botanicals, highest average mycelial growth inhibition was recorded with bulb extract of garlic (67.30%) followed by leaf extract of eucalyptus (60.08%), neem (56.28%) and turmeric (54.37%). Whereas, desi baval (43.67 mm), Lantana camera (58.00 mm) and tulsi (64.33 mm) were found comparatively less effective.