Original article Antifungal efficacies of plant extracts against Alternaria solani (Ellis and Martin) Jones and Grout under in vitro condition

Abstract

The antifungal activity of crude plant extracts of ten pla nt species, viz., neem (Azadiracta indica), prosopis (Prosopis juliflora), onion (Allium cepa), eucalyptus (Eucalyptus obliqua), pungam (Pongamia pinnata), curry leaf (Murrya koenigii), garlic (Allium sativum), henna (Lawsonia inermis), turmeric (Curcuma longa) and ginger (Zingiber officinale) were evaluated against Alternaria solani (Ellis and Martin) by using poisoned food technique under in vitro conditions. The results showed that turmeric extract recorded minimum radial mycelial growth of 9 .5 0 mm with maximu m per cent inhibition of 8 9.4 4 over control. It was followed by ga rlic observed (12.80 mm, 85.77 per cent) and eucalyptus (24.27 mm, 73.03 per cent) respectively. Extract of C. longa, A. cepa and E. obliquea reduced conidial germination to 91.11, 84.44 and 80.06 per cent over control, respectively. Thermal stability of extracts were tested against pathogen from preliminary screening; extracts of tested plant species were found to be heat stable and aqueous extracts of C. longa showed the highest antifungal activity (10.78 mm), followed by A. cepa (13.42 mm). Results of this study indicated that all plant extracts have the antimicrobial activity among all, both extracts of turmeric and garlic were strong inhibitors of this fungus and to levels comparable to standard fungicides.