Bijaya Laxmi Maharjan*, Shaila Basnyat* and Kanti Shrestha**
*Central Department of Microbiology, Tribhuvan University, Kathmandu
**Nepal Academy of Science and Technology, Khumaltar, Lalitpur
Abstract
Solanum tuberosum (Potato) is one of the most important tuber crops with the Production of 325 million tons worldwide per year. In the present study an attempt has been made to screen and evaluate the antifungal activity of plant extracts against the fungal pathogens of potato plant. Crude ethanolic extracts of five different plant materials viz. Brassica nigra (cake). Cinnamomum camphora (fruits), Eupatorium adenophorum (twigs), Lantana camara (twigs) and Melia azedarach (fruits) were screened and tested against the three fungal isolates (Phytophthora infestans, Alternaria solani and Fusarium oxysporum) from diseased potato leaf samples. The antifungal activity) of the crude extracts obtained was evaluated by agar well diffusion method and two fold broth dilution method. C. camphora gave the highest yield of 70% while M. azedarach had the lowest yield of 9.75% of crude extracts. B. nigra was found most effective against P. infestans with both MIC and MFC values 6.25mg/ml. Similarly, M. azedarach showed the higher antifungal activity against A. solani with both MIC and MFC values 3.125mg/ml. C. camphora was found least effective against P. infestans and A. solani while it was most effective against F. oxysporum
with both MIC and MFC values 3. 125 mg/ml. Different types of plant extracts with different concentration significantly inhibited the growth of all the fungal pathogens at P (<0.05). The extracts used in this experiment were found to be suitable for the control of these fungal pathogens.
Keywords: late blight, early blight, fusarial wilt, plant extract