determining the pollinizer for pecan cultivars

this study was conducted to determine the best pollinizer for five selected pecan cultivars in southwest of iran at safiabad agricultural research center in 2014-2015. the cultivars included: 'gratex', '10j', 'wichita 6j', 'graking', 'choctaw' as pollinated cultivars (♀) and 'gratex', 'peruque', 'comanche 4m', '10j', 'wichita 6j', 'mohawk', 'mahan', 'stuart 2j', '3j', 'stuart 4j', 'graking', 'choctaw', 'apache', '6m', 'wichita 7j' and 'comanche 5m.' as pollinizer cultivars (♂). in the first step, a pollination chart of cultivars was determined in two years. the pollination chart of cultivars showed that all the cultivars investigated during this study were dichogamous and also protogynous except for the 'peruque'. ‘graking’ had the longest duration of shedding pollen. pollination chart showed that 'peruque', ‘graking’, and 'stuart 2j' had flowering overlap with the selected cultivars. pollen germination test showed that the germination ability was different among the cultivars. it was 45% for 'graking' and 35% for 'peruque', which were both recommended as pollinizers in this study. '6m', 'gratex' and 'stuart 4j' cultivars had the highest pollen germination percentage of 65%, 60% and 60%, respectively. the results of controlled pollinationtest showed that different pollen sources had no significant effect on nuts per cluster but self-pollinated all of the cultivars significantly reduced fruit set in first and second years. based on the present research, pollination in pecan orchard was necessary for adequate yield. also, 'peruque', 'graking' and 'stuart 2j' were the best pollinizers for five selected cultivars in southwest of iran.