Published online by Cambridge University Press: 15 April 2003
Introduction. The production of `Tahiti' limes in southern Brazil has
increased in the last 20 years and has become a good alternative for citrus growers in
regions where Citrus Variegated Chlorosis has affected sweet orange groves. One of the main
goals to insure success in growing `Tahiti' limes is to apply the right techniques to induce
out-of-season flowering and winter fruit harvest when the fruit prices are the highest.
This experiment evaluated the effects of gibberellic acid application on fruit set
of `Tahiti' lime trees related to out-of-season flowering and accumulated degree days.
Materials and methods. Eight-year-old plants were treated with five concentrations
of gibberellic acid [ (0, 10, 25, 50 and 100) mg$\cdot$L-1] applied during anthesis
of out-of-season bloom. Accumulation of degree days for fruit set and fruit development
in the conditions of São Paulo State, Brazil, were calculated. The percentage of fruit set
determined by weekly counts of the number of flowers from anthesis to the maturation of the
fruits were determined on each previously marked branch. Data were submitted to regression
analysis. Results and discussion. In regard to fruit set, it was observed that 10 mg
gibberellic acid$\cdot$
L-1 was enough to retain more than 10% of fruits in relation
to the number of formed flowers. Starting from anthesis, (837.7 and 1 115.2) accumulated
degree days were necessary for the stabilization of the fruit set and fruit maturation,
respectively.