EFFECT OF N-PHENYL-PHTHALAMIC ACID AND FERTILIZATION ON FLOWERING, FRUIT SET AND FRUIT QUALITY PARAMETERS OF SWEET CHERRY

The influence of N-phenyl-phthalamic acid (NPPA, Nevirol 60 WP) and nutrient fertilization on flowering, fruit set and fruit quality of five sweet cherry (Prunus avium L.) cultivars (Burlat, Germersdorfi, Hedelfingen, Katalin and Van) was studied. The use of NPPA plus fertilizer applications improved fruit set and increased yield. There was a significant difference between cultivars. The most sensitive to the treatments were ‘Germersdorfi’ and ‘Van’. To use NPPA effectively, an increased need for fertilizer also must take into consideration due to the effect on increasing yield; otherwise, fruit mass and diameter will decrease, negatively affecting potential yield.