‘BRS PRINCESA’ ROOT SYSTEM DISTRIBUTION AND WATER EXTRACTION UNDER DIFFERENT IRRIGATION STRATEGIES

Abstract

The aim of this study was to evaluate root distribution and water uptake patterns of the ‘BRS Princesa’ banana under different irrigation strategies in the semiarid region of northern Minas Gerais. To conduct the experiment, fve irrigation strategies were adopted: 50% of water depth reduction (WD), with a 7 day alternation frequency (AF) for the irrigated side of the plant; 50% of WD and AF of 14 days; 50% of WD 21 days; 50% of fxed irrigation WD (one lateral line on only one side of the plant); and full irrigation (two lateral lines with the valve open) throughout the cycle, with samples being collected in four different distances from the pseudostem (0.25, 0.50, 0.75 and 1.0 m) and in fve different soil depths (0.05 to 0.15; 0.15 to 0.25; 0.35 to 0.45; 0.55 to 0.65 and 0.75 to 0.85 m). The experiment was arranged in a completely randomized 5 x 4 x 5 factorial design, with three replicates. Average root length density (RLD) was similar among treatments; however, when the banana was subjected to irrigation with partial water defcit, the plant exhibited greater root development; there is a reduction of RLD with the soil depth and maintenance of distribution of the roots with distance from the pseudostem; very thin to small roots are concentrated in a depth of 40 cm in the soil profle and 70 - 90% of these roots are located up to 75 cm from the pseudostem; a shorter interval of alternation of the irrigated side in PRD enables extraction of water in deeper layers.