EFFECT OF FOLIAR APPLICATION OF ZINC PLUS BORON ON SWEET CHERRY FRUIT SET AND YIELD

The influence of combined Zn and B foliar fertilization on fruit set and yield was studied for two years on sweet cherry (Prunus avium) cvs. ‘New Star’, ‘Giorgia’ and ‘Bing’ grafted on Mazzard rootstock. The influence of Zn and B foliar sprays on yield was determined by counting the number of flowers and the number and mass of fruits on one branch of each experimental tree. Zinc application was made at the end of dormancy (before the vegetative growth in the spring), while B was applied twice: at the beginning of flowering and at full bloom. The treatments were replicated fivefold and treatment differences were assessed by t-test. There was a general trend for fruit set and yield to be higher in the Zn plus B treatment trees compared to the control trees; however, none of the differences in measured responses were statistically significant.