THE PRESENT investigation was conducted during two …….successive seasons of 2011 and 2012 on "Hollywood" and "Golden Japanese" plum trees (Prunus salicina). The trees were 15 years old and grown in private orchard at Menofia governorate. Gibberellic acid at 25 and 50 ppm alone or combined with citric or ascorbic acid at 50 ppm were sprayed twice (at full bloom and 2 weeks later) on both plum cultivars.
All treatments increased fruit set (%) and fruit yield (Kg/tree) and improved fruit quality of the two cultivars in the two studied seasons. The most effective treatment on fruit yield increment and fruit quality improvement was spraying gibberellic acid at 50 ppm combined with citric or ascorbic acid at 50 ppm (at full bloom and 2 weeks later).