Herbicidal potential (phytotoxic) of honey bee propolis extracts of the Brazilian northeast on weeds of cultivated pastures

Abstract

Propolis is made up of complex mixtures of substances made by bees and has shown great potential for use in diverse human applications over the years, but studies reporting its herbicidal activity are still very scarce in the literature. This study aimed to characterize the chemical composition and the allelopathic potential activities of different propolis types from the state of Rio Grande do Norte, Brazil. The extracts mixed in eluent 80% ethanol were tested on the seed germination and the growth of the radicle and hypocotyl weed areas of cultivated Mimosa pudica and Senna obtusifolia pastures. The extracts exhibited that the allelopathic activity intensities varied with the concentration, origin of the propolis, receptor plant, and examined plant part. The intensities of the inhibitions were positively associated with the concentration, reaching maximal inhibitions verified at 0.75% and 1.0%. The inhibition of germination was the most noticeably influenced factor. Malice was the test plant most sensitive to the effects of the extracts. In comparison, the extract of red propolis showed greater potential to inhibit the germination and development of the two receptor plants, particularly the seed germination, when the differences were most striking.