a study on growth and quality characteristics of budded asian pear (pyrus serotina rehd.) cultivars on european pear (pyrus communis l.) seedling rootstocks under tehran environmental conditions

to evaluate growth characteristics and adaptation of new asian pear cultivars (pyrus serotina rehd.) in iran, some growth characteristics and physiological factors of nine asian pear cultivars named ‘ks’6, ‘ks’7, ‘ks’8, ‘ks’9, ‘ks’10, ‘ks’11, ‘ks’12, ‘ks’13, ‘ks’14 and one european, present commercial cultivar ‘shahmiveh’ of iran (control) were evaluated under the climatic conditions of tehran province. the experiment was carried out employing nine asian pear cultivars grafted on european pear (pyrus communis l.) seedling rootstocks. some growth characteristics and physiological factors of budded plants were assessed during two growing seasons. the results showed that more than 80% of grafting was a success in the first season and survival of budded trees amounted to 100% towards the end of the second growing season. budded cultivars showed different growth responses in terms of shoot growth, trunck cross sectional area (tcsa), leaf number and area in the first and second seasons growth. ‘shahmiveh’ (control), ‘ks’7 and ‘ks’11 cultivars had the highest shoot length, leaf number, tcsa and leaf area in the first season. ‘shahmiveh’ showed a higher absolute growth rate (agr) by the end of the first season's growth. although, the differences between asian pear cultivars in terms of agr were not significant but these cultivars showed a higher agr than ‘shahmiveh’ cultivar during the second season's growth. the differences on such leaf mineral concentrations as n, p, k, ca, mg, mn and zn among studied cultivars were significant. the highest n, p, and k was observed in ‘ks’9, ‘ks’12 and ‘ks’6 cultivars respectively, while the lowest concentration was respectively shown in ‘shahmiveh’, and ‘ks’7. the lowest ca, mg and the highest mn were observed in ‘shahmiveh’ cultivar. in total, asian pear cultivars showed a good growth performance on european pear seedling rootstocks under tehran province, environmental conditions. they, after being established, demonstrated a good growth characteristics and efficient nutrient absorption.