Leaf anatomy of Urochloa brizantha and Urochloa ruziziensis (Poaceae) plants subjected to different fertilization management practices

Abstract

Brazilian agribusiness is heavily influenced by beef export. Thus, it is important to evaluate the quality and growth rate of forage species used as cattle food. Given that the structural organization of leaf cells and tissues is directly related to forage-plant growth, we aimed to analyze the foliar anatomy of Urochloa brizantha and U. ruziziensis subjected to different fertilization management practices. Experimental design was completely randomized split-split-plots. Plots were allocated to fertilization strategies, namely single and split fertilizer application. Subplots were allocated to two fertilizer doses for the carrying capacities of 7 and 10 head of cattle per hectare (AU ha-1). Sub-subplots were distributed to the forage plant species U. brizantha and U. ruziziensis. Three leaves were collected from each treatment for the anatomical processing of cross-sections, epidermal imprints and diaphanizations. Based on a parsimonious model, U. brizantha showed thicker leaf tissues than U. ruziziensis. Split fertilizer application increased thickness of the adaxial and abaxial cuticle and of bulliform cells. Fertilizer dose of the higher carrying capacity determined increased thickness of the leaf blade, bulliform cells, and regular homogeneous parenchyma on both studied species. We concluded that increased fertilizer dose and split application interfere with the leaf anatomy of U. brizantha and U. ruziziensis, providing both species with enhanced growth and yield.