The efficacy of leaf - applied herbicides is influenced by the morphological and physical-chemical characteristics of the leaf surface on which the herbicide solution is sprayed. The topography of the leaf surface, thickness of the cuticle, and the degree and type of epicuticular wax and the presence and type of trichomes, are characteristics that influence the distribution of the herbicide spray solution on the leaf surface and thus the efficacy of weed control. Therefore, the objective of this experiment was to obtain information on the morphological characteristics of three foliar surfaces of prickly sida (Sida rhombifolia, Sida glaziovii and Sida cordifolia). The experiment was conducted at the Electronic Microscopic Center Applied to Agriculture (NAP/MEPA), of Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo, Piracicaba-SP, Brazil. The experiment using electronic microscopy technique showed that the species S. rhombifolia presented a higher amount of epicuticle-striped wax while the species S. cordifolia presented a flat and smooth cuticle. The species S. glaziovii showed the highest amount of trichomes on the adaxial foliar surface. All the species analyzed had stomata in both surfaces of the leaves, with a predominance of the anomocytic type.
scanning electron microscopy; weeds; Malvaceae; epicuticular wax
