Antifungal activity of extracts of Melia azedarach and Ageratum conyzoides against Lasiodiplodia pseudotheobromae through in vitro test

Lasiodiplodia pseudotheobromae is one of the pathogens of the cocoa dieback disease. Currently, the disease is considered a significant disease in cocoa, which is a newly emerging disease in Sulawesi. The control tools and methods remain unexplored comprehensively. The main objective of this study was to evaluate Melia azedarach and Ageratum conyzoides leaf extract to inhibit the growth of the L. pseudotheobromae. Three different concentrations were applied for each weed extract, namely: 1%, 3%, and 5%. The experiment was conducted through the poison food technique method both in solid medium and liquid medium. M. azedarach and A. conyzoides were significantly inhibited the colony growth of L. pseudotheobromae in all concentrations in solid medium. However, A. conyzoides 5% performed well to suppress the colony growth of L. pseudotheobromae (42.7%), followed by M. azedarach 5% (16.0%). The mycelium biomass of L. pseudotheobromae was significantly inhibited by M. azedarach and A. conyzoides as well. A. conyzoides 5% showed a higher inhibition of the fungal biomass either wet biomass (90.3%) or dry biomass (95.5%), followed by M. azedarach 5% both wet biomass (85.6%) and dry biomass (78.1%). M. azedarach and A. conyzoides remain to inhibit the colony growth and fungal biomass regardless of the type of concentrations. M. azedarach and A. conyzoides can potentially be an option for controlling dieback disease caused by L. pseudotheobromae.