Study on fungicidal effect of plant extracts on plant pathogenic fungi and the economy of extract preparation and efficacy in comparison to synthetic/chemical fungicides

Abstract
Providing food security to devastatingly increasing population with limited natural resources along with destruction caused by pre- and post-harvest pathogens are the foremost concerns for the developing countries. Numerous pesticides, herbicides and chemical fertilizers are being applied by the farmers to deal with the existing situation but leave very disastrous and undesirable after effects on ecosystem as non-degradable molecules.. Botanicals can be utilized as an ecofriendly and effective alternative against chemical as they are of natural origin. In this context, two chemical/synthetic fungicides namely Manzate and Nystanin in three different concentrations namely 500ppm, 1000 ppm and 1500 ppm were evaluated against Sclerotium rolfsii, Alternaria alternata, Fusarium monilifrome, Rhizoctonia solani and Aspergillus niger in vitro to compare them with ethanolic botanical extracts of spices (clove, cinnamon, thyme) and weeds (parthenium and calotropis) at 5%, 10%, 15%, 20% and 25%. Results revealed the high efficacy of botanicals i.e. clove extracts showed maximum inhibition (100%), followed by reduced inhibition in cinnamon, thyme, Parthenium and Calotropis treated plates against all five pathogens even at 5% concentration in comparison to chemical of 500 ppm concentration i.e. 100% in case of S.rolfsii only. Hence the herbal products can be further analyzed and applied as a potent, ecofriendly and economical substitute to chemicals.