With the development of pecan orchards in subtropical regions of Iran in recent years, it is very important to release vigorous and hot weather tolerant rootstocks for grafting. For this purpose, 15 pecan cultivars were evaluated in terms of seed germination rate, seedling growth rate, and summer heat stress damage in 2019-2021 at Safiabad Agricultural Research Center. The cultivars were included ‘GraTex’, ‘Peruque’, ‘Comanche 4M’, ‘10J’, ‘Wichita 6J’, ‘GraKing’, ‘Choctaw’, ‘Apache’, ‘Wichita 7J’, ‘Comanche 5M’. ‘Stuart 2J’, ‘Stuart 4J’, ‘6M’, ‘Mahan’ and ‘Mohawk’. The evaluated traits were seed germination rate, determination of seedling production index per kilogram of seed, seedling height and diameter, and amount of seedling damage due to heat stress. The results showed that ‘Peruque’, ‘Apache’, ‘Mohawk’, and ‘Wichita 7J’ were preferred with the possibility of producing 126, 86, 75, and 74 seedlings per kilogram of seed, respectively. The results of the height and diameter of the seedlings showed that ‘Peruque’, ‘Stuart 2J’, ‘Comanche 5M’, ‘Mahan’ and ‘Apache’ were vigorous. The heat stress was so intense in 2021 that even several decades old and large pecan trees were damaged. Meteorological information of Safiabad station showed that, the temperature was above 45 degrees Celsius for 435 hours in 2021. The results showed that the seedlings of ‘Peruque’ and ‘Apache’ were the most tolerant and ‘GraTex’ and ‘Mohawk’ were very sensitive. According to the evaluation of seedlings of pecan cultivars in the years, 2019 to 2021, ‘Peruque’ and ‘Apache’ for pecan rootstock production are recommended. پرونده مقاله

This research was conducted to determine the most appropriate grafting method for pecan trees in Dezful between 2019- 2022. Two experiments were carried out based on a completely randomized design in the form of a split-plot in three replications with grafting time at eight levels (from the second week of March to the first week of May) and three scion cultivars: ‘GraKing’. ‘Wichita’ and ‘Choctaw’. In the first experiment, fresh scions were used, and in the second experiment, the scions were prepared and kept at 4oC for one month. The results of the first experiment showed that the grafting success in the first week of March was significantly higher than other dates at the level of 1%. The grafting was not successful in the second week of March and the first week of May. In the second week of April, ‘Choctaw’ had the highest rate of grafting success with 94%. The effect of grafting date and scion cultivar was significant at the 5% probability level in the growth, and ‘Choctaw’ had the highest height and diameter in the first and second year. In the second experiment, the results showed that the grafting success was significantly highest in the first week of April and the grafting was not successful in the second and third weeks of March. Finally, the middle of April was recommended as the best time for pecan trees top-working in Dezful condition. پرونده مقاله

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. پرونده مقاله