EFFECT OF BA (6-BENZYLADENINE) AND GA₄₊₇ ON FEATHERING OF SWEET CHERRY CULTIVARS IN THE NURSERY

A series of trials was begun to determine the effect of 6-benzyladenine (BA) on feathering of one-year-old sweet cherry trees in the nursery. In the first trial (1993), 0.02% BA (water soluble formulation, Paturyl 10 WSC) treatment, applied 3 times, did not affect the number and length of long shoots; however, the number of spurs increased significantly. In a further trial (1997), BA was applied 3 times alone or plus two additional GA₄₊₇ applications to one-year-old 'Germersdorfi óriás' sweet cherry trees. Growth was measured at the end of the growing season, as were the number and length of laterals. BA treatments significantly increased the total number of laterals compared to the untreated control. Additional GA₄₊₇ treatments did not affect the total number of laterals, but increased the length of lateral shoots. In 1998, the effect of different BA concentrations (0.04%, 0.06% and 0.08%) and repeated treatments on lateral shoot formation was studied. Three applications of 0.04% BA with two additional GA₄₊₇ sprays improved the feathering of `Biggareau Burlat', 'Germersdorfi óriás', and 'Linda' in the nursery. The higher concentration (0.06%) increased the number of short shoots and decreased apical growth of nursery trees of the easily feathering 'Van'. The repeated sprays (3x, 4x, 5x) of the higher (0.06%) BA concentration did not affect the terminal growth of 'Van' trees, but improved the formation of lateral shoots shorter than 30 cm. We conclude that 0.04% BA sprayed three times plus two GA<sub>4+7</sub> sprays is suitable to improve the feathering of one-year-old sweet cherry trees in the nursery. More applications might be needed to increase the number of short shoots and decrease apical growth of `Van’ cherry trees.