The objective of this study was to evaluate the effect of different concentrations (0; 50; 100 and 150 mg L-1) of paclobutrazol (PBZ) on growth, side shoot emission and yield of two tomato hybrids (Jennifer and AF 7631), cultivated in open field and in protected environment. The work was conducted from April to October of 2007, at UNESP - Campus of Ilha Solteira, State of São Paulo. The PBZ was applied to seedlings 15 days after sowing, and its effects were evaluated, considering the tested concentrations, for tomato plants after the transplant. A randomized blocks design was used, in a factorial scheme, with analysis for series of experiments, in a fixed model, consisting of 4 replicates for environment and 9 plants per plot. As results, the hybrid Jennifer showed higher rates of absolute growth, resulting in higher plants than AF 7631, on the 60th day after the transplantation, but, with no differences between them regarding side shooting and crop yield. In the greenhouse, higher plants were obtained, with higher side shooting and higher yield than that observed in the open field. The use of increasing concentrations of paclobutrazol reduced the height of plants and their growth rate, decreased side shooting, and reduced the crop yield.
Solanum lycopersicum L.; growth regulator; greenhouse
