Antifungal activity in vitro of Flourensia spp. extracts on Alternaria sp., Rhizoctonia solani, and Fusarium oxysporum

There are 32 species of Flourensia genus with 9 native to Mexico. These species contain compounds with potential use for pest control. In this paper, we report the antifungal activities of ethanol extracts from three endemic species in Coahuila state: Flourensia microphylla, Flourensia cernua, and Flourensia retinophylla. Also, preliminary information on the chemical composition of the extracts is included. Antifungal activity was tested against three pathogens attacking commercial crops: Alternaria sp., Rhizoctonia solani, and Fusarium oxysporum. The extracts concentration varied from 10 to 1500 mu l l(-1). The ANOVA showed highly significant differences (P <= 0.01) with the extracts, the doses, and on the interaction extract x dose. Inhibition effect was observed from 10 R mu l(-1) in all three species. Total inhibition was found only with F cernua and F retinophylla at 1000 mu l l(-1) for R. solani, the three species inhibited the three pathogens at 1500 mu l l(-1). Infrared analysis showed similar absorption signals for the extracts of the three species although in different concentration. This suggests that similar compounds may be present. The control of these pathogens by natural compounds is interesting both for environmental and economic reasons. The use of semiarid lands plants may improve the socioeconomic level of the people within the region. (c) 2006 Elsevier B.V. All rights reserved.