Efeito de diferentes adubações e lâminas de irrigação sobre o crescimento inicial da mandioca

Abstract

Cassava (Manihot esculenta Crantz) stands out as one of the main crops with socioeconomic relevance in Brazil, especially in tropical and semi-arid regions. Among the practices that can enhance plant productivity and quality, a promising alternative is the use of foliar sprays and pre-plant treatments of cuttings. In this context, the objective was to evaluate the influence of nutrient solution application by immersion and foliar spraying associated with different irrigation levels on the initial growth of cassava. The experiment was conducted in a greenhouse at the Campus of Engineering and Agricultural Sciences of the Federal University of Alagoas, in Rio Largo – AL. The experimental design was completely randomized in a 3 × 2 factorial scheme with four replications, the first factor consisting of three fertilization methods (immersion, foliar spray, and absence of fertilization) and the second factor of two irrigation levels (100% and 50% of field capacity). Growth variables were evaluated (number of leaves, plant height and stem diameter, fresh and dry shoot biomass, root density, fresh and dry root biomass, and Dickson Quality Index), as well as chlorophyll variables (chlorophyll A and B). The results were subjected to analysis of variance using the F test, and means were compared using Tukey’s test at 0.05. Foliar spraying showed superiority for shoot biomass at 30 DAP, stem diameter at 45 DAP, fresh and dry shoot biomass, fresh and dry root biomass, and DQI. Water stress affected chlorophyll A and B production, presenting higher values than those under full irrigation. The combination of agronomic strategies favored crop development, mainly regarding shoot biomass and number of leaves at 45 DAP, fresh shoot biomass, and root density, demonstrating that adequate fertilization, combined with proper irrigation management, enhances the initial growth of the crop.