Effect of Aqueous and Hydroalcoholic Extracts of Hyptis suaveolens (L.) Poit. (Lamiaceae) on Seedlings of Three Cultivated Species: Zea mays L. (Poaceae), Phaseolus vulgaris L. (Fabaceae), and Solanum lycopersicum L. (Solanaceae)

Synthetic herbicides use in weed management has negative effects on human health and environment. This study was carried out to assess the allelopathic effects of Hyptis suaveolens on seedlings of Solanum lycopersicum, Zea mays and Phaseolus vulgaris. Aqueous and hydroalcoholic solvents at concentrations of 10% and 20% were used to prepare extracts from fresh and dried leaves of this species in foliar and root application in honeycomb plates. The results showed that extracts of Hyptis suaveolens leaves inhibite the development of seedlings of the target species in root application. Concerning the effect of the extracts on the development of Zea mays seedlings, the 20% hydroalcoholic extracts of dry and fresh leaves showed a better mortality rate. This rate varied between 61.67% and 71.08% depending on the species. For Phaseolus vulgaris seedlings, the 20% hydroalcoholic extract of fresh leaves showed a better mortality rate (72.43%). In the case of Solanum lycopersicum seedlings, the aqueous extract of dried leaves induced a better mortality rate (88.97%). It may be concluded that extracts of Hyptis suaveolens leaves could be sprayed as bioherbicide.