Bananeira ‘Prata-Anã’ e ‘Grande Naine' sob aplicação de Paclobutrazol no solo e 2,4-D em pré-colheita: uma abordagem multivariada

Abstract

The use of growth regulators can increase the production of plant species or reduce the size to allow for the densification of crops. The objective of this work was to evaluate the production and post-harvest characteristics of 'Prata-Anã' and 'Grande Naine' banana in the first, second and third cycles as a function of paclobutrazol in soil and 2,4-D in pre- -harvest. A randomized block design in a 4 x 4 factorial arrangement was used for the concentrations of paclobutrazol (0, 0.1, 0.3, 0.5 g L-1) and 2,4-D (0, 10, 20, 30 mg L-1) with three repetitions. In the flowering of the plants, five vegetative and one physiological characteristics were evaluated, in the bunch harvest, nine production variables were evaluated and after the fruit harvest, five fruit quality variables were evaluated. For the 'Prata – Anã' banana, there were increases in the values of seven production variables and a decrease in the value of one production variable as three production cycles followed. There is no effect of auxin doses on the characteristics associated with fruit production. However, higher doses of auxin tended to show lower fruit firmness. Higher PBZ doses provide higher estimates for two postharvest variables. Higher paclobutrazol doses lead to lower estimates for six production variables and three vegetative variables. For the 'Grande Naine' banana, there was no effect of the paclobutrazol and auxin treatments to increase the values of six production variables in three production cycles. The main effect for the increase in the values of production variables was due to the increase in vigor, height and productivity of plants during the three production cycles. The dose of 0.5 g i.a paclobutrazol plant-1 in the first and second production cycle provided lower estimates for three production variables and two growth variables and presented higher estimates for the physiological variable chlorophyll index (SPAD). Doses of paclobutrazol and auxin did not show results for postharvest variables in the first production cycle. Higher doses of auxin provided, in the second and third production cycles, lower estimates of Firmness, pulp pH and Brix, demonstrating an influence on fruit ripening.