Yield and fruit quality of Barhee date palms as affected by gibberellic acid, boron and active dry yeast sprays

The present investigation was conducted over two consecutive seasons on 15-year-old Barhee date palms (Phoenix dactylifera L.) cultivated in an exclusive orchard 63 kilometers along the Cairo-Alexandria Desert Road in sandy soil under a drip irrigation system. For three times, bunches of the tested palms were misted with GA3, boric acid, or active dry yeast: once a day before pollination, once a month after fruit set, and once a month before harvest. GA3 was sprayed at the previous dates with 50, 100, and 50 ppm, respectively, while boric acid was sprayed at the same dates with 2000, 1500, and 1000 ppm. Similarly, active dry yeast was sprayed at the same dates with 250, 500, and 250 ppm. The investigated treatments were compared with untreated palms. The findings indicate that all spraying treatments improved fruit properties, both chemical and physical, and boosted fruit set and yield compared to the control. In general, the most effective treatment to increase fruit set, production, and the physical and chemical properties in both seasons was the procedure of spraying inflorescences with active dry yeast three times (250, 500, and 250 ppm).