Trocas gasosas em genótipos de bananeira tipo maçã

Abstract

The objective of this study was to evaluate the gaseous exchange of apple-type bananas, at different times of the year and at times, in a semi-arid environment. The treatments, seven genotypes, Maçã, Caipira, BRS Tropical, BRS Princesa, YB42-03, YB42-17 and YB42-47, were arranged in a completely randomized experimental design with five replicates and four useful plants per plot. For the physiological characteristics, a 7x7x2 factorial arrangement was considered, seven genotypes, seven evaluation times, two reading times, 8 and 14 hours. The gas exchange, the carboxylation efficiency and the instantaneous efficiency of the water use are higher at 8 hours, favored by the climatic conditions, while the leaf temperature and the transpiration rates are higher at 14 hours, due to the elevation of the air temperature and Low humidity. The months of July, August and September allow the banana plants to express higher values of photosynthesis rates and greater efficiency of carboxylation and photochemistry of photosynthesis. The genotypes YB42-47 and Maçã present higher values of water use efficiency and photosynthesis rates, not reflecting in productivity, with genotypes YB42-17 and BRS Tropical being the most productive in the 2nd cycle.