The rootstock type affecting fruit yield, and quality, and fire blight resistance of ‘Dargazi’ and ‘Beyrouti’ pear genotypes

Finding and developing pear genotypes, with superior fruit production and disease resistance is of significant health and economic importance. Therefore, this study investigated the growth, fruit yield, and disease resistance of the ‘Dargazi’ and ‘Beyrouti’ (Louise Bonne) pear genotypes grafted onto PyroDwarf and OH × F 69 rootstocks. The two-year experiment (2019–2020 and 2020–2021) was performed at the Garden of Astan Quds Razavi, Mashhad, Iran. The results showed variation in growth and bearing properties of different combinations of PyroDwarf and OH × F 69 rootstocks with ‘Beyrouti’ and ‘Dargazi’ genotypes throughout the experimental years. The OH × F 69 rootstock, significantly increased tree height (by 12%), shoot growth and internode length of the experimental genotypes, related to the PyroDwarf rootstock. However, higher trunk diameter (by 20%) and leaf area density of both genotypes were found in PyroDwarf rootstock. Although the time of blooming and fruit ripening were different between the ‘Dargazi’ and ‘Beyrouti’ genotypes, they were not influenced by the rootstock type. ‘Dargazi’ genotype and PyroDwarf rootstock produced the highest number (35.53 per tree), weight (195.04 g, 96.20% higher than ‘Beyrouti’) and yield (4.95 kg per tree, 2.1 times higher than ‘Beyrouti’) of pear fruit significantly enhancing yield attributes in both genotypes. The quality of fruits was also affected by the combination of genotypes and rootstocks. The grafted ‘Dargazi’ genotype on PyroDwarf rootstock showed lower tree infection by fire blight and psylla. The ‘Dargazi’ genotype grafted on the PyroDwarf rootstock may be recommendable to achieve high pear fruit yield and quality.