The effect of 10 ppm 3,5,6-TPA (3,5,6-trichloro-2-pyridyloxyocetic acid), 20 ppm GA
3 and their combination on size and weight of cherry fruit (Prunus avium L. ‘Regina’) were studied. 3,5,6-TPA was applied 25 days after full bloom and GA 3 during stage of fruit color change from green to straw-yellow. Fruit height, width, thickness and weight were measured. Width, thickness and weight of control fruit were the smallest.
Fruit from 3,5,6-TPA - treated trees did not show significant difference in comparison to control. However, fruit from GA 3 – treated trees had significantly improved all characteristics in comparison to control fruits. Weight of fruit from trees treated with combination of 3,5,6-TPA and GA 3 was 14% higher than control fruit and 2.8% higher than fruit from GA 3 - treated trees, but there was no significant difference comparing to fruit from trees treated with GA 3 alone. These results are preliminary results after a one-year study and more research should be done to examine the possible influence of other factors, such as ecological factors, before final management recommendations could be made.