Fruit drop rates of 9 sour cherry cultivars (‘Érdi bőtermő’, ‘Debreceni bőtermő’, ‘Kántorjánosi’, ‘Újfehértói fürtös’, ‘Éva’, ‘Petri’ ‘Oblacsinszka’, ‘Pandy 279’ and ‘Csengődi’) were studied. Trees were eight years old, grafted on Prunus mahaleb and grown in Újfehértó, located in the Eastern north part of Hungary. Significant differences have been found in fruit set among cultivars. The average fruit set was 18.3%; ‘Oblacsinszka’ fruit set was highest (32.6%), while ‘Debreceni bőtermő’ and ‘Pandy 279’, was lowest (12%). Seasonal changes for fruit set and drop revealed four abscission peaks. The first fruit abortion wave appeared during the second week after pollination. Thereafter, the second and third periods occurred during the third and fourth weeks after pollination. The fourth abscission peak was during the fourth week after pollination. The highest fruit drop occurred in ‘Pandy 279’ (92.4%) followed by ‘Éva’ (90%), while the lowest fruit drop was observed in ‘Oblacsinszka’ (71.5%).

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