FOLIAR SPRAYS OF UREA AND GIBBERELLIC ACID ON BLOOM AND PRODUCTION OF RED RASPBERRY ?AUTUMN BLISS?

Abstract

The purpose of this research was to study the response of red raspberry (Rubus idaeus L.) ?Autumn Bliss? to foliar applications of gibberellic acid (AG3) and urea. Spraying 50 mg L-1 of AG3 + 10 g L-1 urea in 16-node plants accelerated blooming 18 days, and 13.5 days in 18-node plants, with respect to the control. However, fruit yields were reduced 53 % and 56 %, respectively. In 14-node plants two sprays of 50 mg L-1 of GA3, alone or mixed with urea (10 g L-1), accelerated flowering in 8 and 3 days, respectively. The yield per plant were also reduced 43 % for both treatments. In 14-node plants, a single application of 50 mg L-1 of GA3 delayed blooming by one day but yields were increased 23% in relation to the control.