Effect of gibberellic acid and temperature on germinatio of Vitex montevidensis Cham.

Abstract

This work aims to evaluate treatments that may help improve speed and uniformity of germination in fruit tree species tarumã. Data were obtained from pyrenes (stones) of ripe fruits which in turn were picked from adult trees in the municipality of Vera Cruz do Oeste-PR. Treatments consisted of applying GA3 solutions at various concentrations (zero, 50 mg L-1, 100 mg L-1 or 200 mg L-1) to pyrenes via immersion for 47 hours, and thermoperiods of alternate 20ºC and 30ºC (8 hours at 20ºC in light conditions, and 16 hours at 30ºC in dark conditions) and constant 30ºC with the same photoperiod. The combination of alternate temperatures of 20ºC and 30ºC with a 200 mg L-1 GA3 solution resulted in an increase both in germination percentage, from 19.2% to 56.2%, and in the germination speed index, from 0.19 to 3.12, with resulting normal, uniform seedlings.