Estratégias de irrigação nas fases fenológicas da bananeira sob adubação potássica.

Abstract

The banana crop is of great socioeconomic importance both for Brazil and worldwide, but its production may be limited by low water availability. Therefore, irrigation management strategies combined with potassium fertilization are promising alternatives for agricultural production in these regions. In this sense, the objective was to evaluate the morphology of banana cv. Nanica under irrigation management strategies and potassium fertilization in the phenological stages of the plants. The research was carried out under field conditions, located in São Domingos/PB, using a randomized block design in a 3 × 2 factorial scheme, whose treatments resulted from the combination of three irrigation management strategies: with water deficit in the phenological phases irrigation with 50% (water deficit) in the juvenile phase - JU and fruiting phase - FR and SE - without stress, 100% of the plant's water requirement throughout the crop cycle, and two doses of potassium applied via soil - DK ( 50 and 100% of K2O), with 4 replications The dose corresponding to 50% of K2O favors the synthesis of chlorophyll a and an increase in the levels of chlorophyll b in banana cv. Nanica under water deficit in the juvenile and fruiting phases at 180 days after planting. The dose corresponding to 50% of K2O promotes an increase in initial fluorescence (F0) and variable fluorescence (Fv) when they receive water stress in the juvenile stages of banana cv. Nanica at 180 days after planting. The dose corresponding to 50% of K2O reduces the maximum fluorescence (Fm) in the juvenile stages under water deficit of banana cv. Nanica at 180 days after planting. Water stress caused in the juvenile phase promotes greater negative effects on growth, water content, damage to the cell membrane of banana cv. Runt. The dose corresponding to 50% of the K2O recommendation reduces the growth of banana plants cv. Nanica at 210 days after planting.