Initial and final fruit set in some plum (Prunus domestica L.) hybrids under different pollination types

The paper presents results of two-year study (2009-2010) of initial and final fruit set in promising plum (Prunus domestica L.) hybrids developed at Fruit Research Institute - Cacak, under different pollination conditions. The following hybrids were studied: 38/62/70 (‘Hall’ x ‘California Blue’), 32/21/87 (‘Stanley’ x ‘Scoldus’), IV/63/81 (‘Large Sugar Prune’ x ‘Scoldus’), 22/17/87 (‘Cacanska Najbolja’ x ‘Zh'lta Butilcovidna’), 29/29/87 (‘Stanley’ x ‘Scoldus’) and 34/41/87 (‘Valjevka’ x ‘Cacanska Lepotica’). Each of the hybrids was studied both under self- pollination and open pollination. In vitro pollen germination was also performed as well as characteristics of flowering phenophase and flowering abundance. Generally, the results suggest lower flowering abundance in the second year of the study. Pollen germination ranged from averagely 25.31% (29/29/87) to 40.01% (38/62/70). With averagely 31.59% final fruit set under self-pollination and 29.38% under open pollination variants, respectively, hybrid 34/41/87 gave the best results. The lowest performance was observed in hybrid 32/21/87 with 1.61% and 7.69% final fruit set under self- and open pollination variants, respectively. [Projekat Ministarstva nauke Republike Srbije, br. TR-31064]