Pollination, Fertilization, Autogamy Degree and Fruit Set of Some Sour Cherry Cultivars in Growing Conditions of Poland

An investigation of the floral biology, fruit set and yield of six sour cherry cultivars ('Schattenmorelle IR-2', 'Koral', 'Debreceni Botermo', 'Ujfehertoi Furtos', 'Karneol', and 'Vowi') was carried out from 2006 to 2009. Flowers of 'Schattenmorelle IR-2', 'Koral' and 'Vowi' had a higher amount of germinated pollen grains per stigma as well as the most fertilized pistils (based on the percentage of pollen tubes that had reached the ovule) than the other cultivars. Most of the germinated pollen grains per stigma and fertilized ovules were noted at the middle or the end of the bloom period, depending on season. High fruit set, both by self-and open-pollination, was obtained in 'Schattenmorelle IR-2', 'Koral' and 'Vowi'. These three cultivars also gave high yields. The Hungarian cultivars ('Debreceni Botermo' and 'Ujfehertoi Furtos') and 'Karneol' set only a few percentage of fruits by autogamy and a bit more by allogamy, and resulted in insufficient yields.