Evaluation of different aqueous plant extracts against rice blast disease fungus (<i>Magnaporthe oryzae</i>)

Abstract

The antifungal potentials of some medicinal plant leaf extracts have been established against fungal diseases. This research work was conducted to evaluate the effects of aqueous plant leaf extracts of five plants: Apple of Sodom (Calotropis procera), Neem tree (Azadirachta indica), Thorn  Apple/Angel's trumpet (Datura metel), Aleo plant (Aleo vera) and Siam weed (Chromolaena odorata)) at different concentration (25, 50, and 100%) against rice blast disease (Magnaporthe oryzae) in-vitro and in-vivo. The research work was laid out in a split-split plot arrangement using a randomized complete block design with three replications. Data were collected for disease severity, disease incidence, number of tillers per plant, number of filled grains, the weight of 1000 grains, and panicle weight. The data collected were analyzed using IRRI STAR software (IRRI, 1979). Percentage inhibition was significantly higher at higher concentrations for all the aqueous plant extracts as compared to lower concentrations. The field trial result shows that there were significant differences among all the studied traits though at different levels for all the sources of variation. The leaf plant aqueous extracts at all the varied concentrations reduced the rate of disease severity and incidence while the number of tillers per plant, the number of filled grains, the weight of 1000 seeds, and panicle weight increased compared to control. The result revealed that Apple of Sodom (Calotropis procera) is the most efficient in combating rice blast disease followed by Neem tree (Azadirachta indica), Thorn Apple/Angel's trumpet (Datura metel), Aleo plant (Aleo vera), and Siam weed (Chromolaena odorata) in that other. These aqueous plant extracts can be used to manage rice blast disease at a low cost and it is ecofriendly compare to chemical fungicides.

Keywords: Disease severity, Magnaporthe oryzae, Medicinal plants, Plant extracts, Rice