Precocidade, produtividade e eficiência de uso de água em bananeira sob densidades de plantio e laminas de irriga??o, em regi?o semiárida

摘要

Banana is a crop of major importance for the Brazilian semiarid region. However, because of the low availability and irregularities of the rainfall in this area, it is necessary to combine techniques that allow a higher water-use efficiency. This study aimed to evaluate the influence of different combinations of irrigation depths and planting densities on the precocity, yield and water-use efficiency of BRS Platina banana plants, in the semiarid region of the Bahia state, Brazil. A randomized block design with four replicates was used, in a split-plot arrangement. Irrigation depths of 55 %, 70 %, 85 % and 100 % of the crop evapotranspiration (ETc) were assigned to the plot, and the planting densities of 1,600 plants ha -1 , 2,000 plants ha -1 , 2,666 plants ha -1 and 3,333 plants ha -1 to the split-plot. The hands weight and number of fruits decreased in a linear way with the increase in the planting density (1,600 plants ha -1 to 3,333 plants ha -1 ) from 10.89 kg to 9.49 kg and from 97.16 to 89.86, respectively; whereas the hands yield (15.5 t ha -1 to 25.79 t ha -1 ) and the harvest period (442 to 455 days) increased. The number of fruits increased linearly from 89.46 to 98.08 with the irrigation depth of 55 % to 100 % of the ETc. The yield and water-use efficiency increased linearly as the planting density increased (1,600 plants ha -1 to 3,333 plants ha -1 ) from 5.14 to 8.60, while the water-use efficiency decreased with the irrigation depth from 7.97 to 5.50, conidering 55 % to 100 % of the ETc. It is possible to obtain higher yields and a higher water-use efficiency by using a higher planting density and irrigation levels below 100 % of the ETc.