Flowering control, development, and growth of cv. Vitoria pineapple using Paclobutrazol

The objective of this work was to evaluate the effect of the concentration of paclobutrazol (PBZ) and the application date in the pineapple ‘Vitória’. The experimental design was in randomized blocks in a factorial scheme (3x3+1), with three concentrations (75, 150, 300 mg L-1) of PBZ and three periods (P1:April-May, P2: May-June, and P3: June-July) and additional treatment (control). Calculation of the flowering, analysis of the plant development, photosynthetic pigments, carbohydrate, total nitrogen, and fruit physicochemical analysis were performed and the data were submitted to analysis of variance and the test of Tukey (p < 0.05). All PBZ concentrations inhibited flowering and a reduction was observed in the inhibition time. The PBZ at the concentration of 150 and 300 mg L-1 inhibited the natural flowering in P1 and P2 and 80% in P3. The PBZ induced the development of leaves in relation to the control, however, the effect reduced as the concentrations increased. Chlorophyll contents were higher with 150 and 300 mg L-1. For the carbohydrate contents, the starch showed asignificant difference. Nitrogen was influenced in the apical and median parts of the leaves. The PBZ reduced the fruit mass and consequently increased the content of Brix, vitamin C,ratio. Therefore, a concentration of 75 mg L-1 is recommended in the period from May to June.