Leaf-surface characterization and the effects of the herbicide saflufenacil on the leaves of weeds

Abstract

Effects of saflufenacil in Merremia aegyptia (Convolvulaceae), Luffa aegyptiaca (Cucurbitaceae) and Mucuna aterrima (Fabaceae - Leguminosae) were analyzed by scanning electron microscopy one day before and after application. Stomatal density, stomatal index and length of the stomatal aperture were determined by imprinting the leaf epidermis. These species showed stomata on the adaxial and abaxial epidermis. M. aegyptia showed paracytic stomata, unicellular tector trichomes on the abaxial surfaces, especially around leaf veins, and absence of epicuticular wax crystals. L. aegyptiaca was characterized by having anomocytic stomata, glandular trichomes and multicellular trichomes on both sides of the leaf, and did not have epicuticular wax crystals. M. aterrima showed anisocitic stomata, glandular and unicellular trichomes on both sides as well as a large amount of epicuticular wax crystals. The herbicide saflufenacil promoted dispersion of waxes, epidermal surface roughness and depletion of trichomes on L. aegyptiaca and M. aterrima plants. There were significant differences in the stomatal index, density and length of stomatal aperture among the studied species.