Antifungal activity of crude extracts of Ageratum conyzoides and Chromolaena odorata for management of Lasiodiplodia theobromae and Lasiodiplodia pseudotheobromae through in vitro evaluation

Abstract

Lasiodiplodia is an important genus of fungi causing destructive diseases on perennial crops, including cocoa. Two crucial species of Lasiodiplodia that cause diseases in cocoa are Lasiodiplodia theobromae and Lasiodiplodia pseutheobromae. A variety of weeds is the potential to be applied as botanical fungicides to control the pathogens. The main objective of this study was to evaluate Ageratum conyzoides and Chromolaena odorata leaf extract to inhibit the growth of L. theobromae and L. pseudotheobromae on a synthetic medium. Solvent organic was methanol for weed extraction with a ratio of 1:5. The experiment was conducted through the poison food technique method, both in the solid and liquid medium in three different concentrations, 1, 3, and 5%. The result showed that A. conyzoides and C. odorata were significantly inhibited the colony growth of both Lasiodiplodia in all concentrations in a solid medium. A. conyzoides performed better than C. odorata in all concentrations of both Lasiodiplodia in inhibition. A. conyzoides 5% performed well to suppress the colony growth of L. pseudotheobromae (100%), followed by A. conyzoides 3% and A. conyzoides 1%. A. conyzoides 5% able to inhibit the colony growth of L. theobromae until 100%, followed by A. conyzoides 3% and 1%. Meanwhile, A. conyzoides and C. odorata extract tested on PDB medium at 1, 3, and 5% reduced the fungal biomass significantly at all concentrations. C. odorata was found most effective in inhibiting fungal biomass of both pathogens either on wet weight or on dry weight at 1, 3, and 5% %. A. conyzoides and C. odorata can manage the growth of L. theobromae and L. pseudotheobromae through in vitro conditions.