The use of plant growth regulators that act on the biosynthesis of gibberellins, as proexadione calcium, may enable proper balance between vegetative growth and fruiting to maximize production indexes. However, the response of this plant growth regulator depends on the pattern of shoot growth. Thus, the aim of this study was to evaluate the effect of application times of prohexadione calcium on vegetative growth control of apple 'Fuji Suprema', in the climatic conditions of Southern Brazil. It was evaluated different application times of prohexadione calcium at 330 g ha-1, in two growing seasons, using randomized complete block design with ten replication of a plant. In the 2008/2009 growing season were evaluated six times of application (28, 58, 88, 118, 148, and 178 DAFB, days after full bloom), and in the 2009/2010 season were evaluated seven times (20, 50, 80, 110, 140, 170, and 200 DAFB), both compared with check treatment (no application). The prohexadione calcium sprayed in a single application at 330 g ha -1 until 28 days after full bloom may reduce the number, weight and average length of pruned shoots in 'Fuji Suprema'apple trees, but in conditions of excessive vegetative growth have not effect. The use prohexadione calcium at 330 g ha-1 in a single application, regardless of timing application has not effect on fruit production of 'Fuji Suprema' apples.
Malus domestica; plant growth regulador; gibberellins biosynthesis; fruit production
