Produtividade e resposta morfológica do capim Andropogon (Andropogon Gayanus) submetida á diferentes níveis de adubação foliar

Abstract

The present study aimed to evaluate the effects of different levels of foliar nitrogen fertilization on the morphogenic growth and productivity of Andropogon grass (Andropogon gayanus), a forage species of great importance in tropical livestock systems. The experiment was conducted in a greenhouse at the State University of Piauí – UESPI, Campus Deputado Jesualdo Cavalcante, in Corrente-PI, using a completely randomized design (CRD), with four foliar fertilization treatments based on Aggro Folhas Completo 20-10-10 + Micros (0, 50, 100, and 150 g/L) and three replications, totaling 12 experimental units. The variables evaluated included plant height, leaf length and width, number of tillers, and leaf area over 45 days. The results showed that the 50 g/L concentration provided the best growth indices, with greater leaf length and width, as well as higher tillering, indicating a positive and balanced effect of foliar fertilization on forage development. In contrast, higher concentrations (100 and 150 g/L) caused negative effects similar to the control, with a marked reduction in the evaluated characteristics, suggesting possible phytotoxicity. It is concluded that foliar nitrogen fertilization, when applied at appropriate doses, can be an effective tool to enhance the performance of Andropogon grass, representing a complementary alternative to soil fertilization. However, it is necessary to pay attention to the precise definition of doses and management practices to avoid performance losses and ensure greater nutrient use efficiency.