Ethanolic extract of Copaifera, Croton and Lippia on the control of phytopathogenic fungi

Abstract

ABSTRACT The search for vegetable extracts for phytosanitary control has been expanded to find new active ingredients to control plant diseases. This study aimed to evaluate the in vitro effect of the fixed constituents of Copaifera luetzelburgii, Croton zehntneri and Lippia lasiocalycina, at the concentrations of 2, 20, 200 and 2,000 μg mL-1, on the percentage of mycelial growth inhibition of Colletotrichum siamense, C. truncatum, Fusarium sacchari, F. udum, Lasiodiplodia theobromae and Thielaviopsis ethacetica, as well as the conidium concentration of C. siamense, F. sacchari and F. udum produced in culture medium with all the extracts. The tested ethanolic extract, especially at the highest concentration, inhibited the percentage of mycelial growth and/or conidium concentration of the evaluated fungi. The other concentrations showed low inhibitory effects or no activity against the fungi. The average values for percentage of mycelial growth inhibition of the ethanolic extract from L. lasiocalycina, C. zehntneri and C. luetzelburgii against the six fungi were 62.5, 53.4 and 51.0 %, respectively. The ethanolic extract of L. lasiocalycina showed the most significant effect on the percentage of mycelial growth inhibition and conidia concentration. The fixed constituents of C. luetzelburgii, C. zehntneri and L. lasiocalycina at 2,000 μg mL-1 showed to be efficient in inhibiting the mycelial growth of C. siamense, C. truncatum, F. sacchari, F. udum, L. theobromae and T. ethacetica, and inhibit the conidia production of C. siamense, F. sacchari and F. udum.