COMPARISON AMONG PEAR TRAINING SYSTEMS AND ROOTSTOCKS FOR HIGH DENSITY PLANTING (HDP) OF THE CULTIVAR 'ABBÉ FÉTEL'

Nowadays, early bearing and smaller tree size in pear orchards can be achieved decreasing spacing among trees and grafting them on quince rootstocks which are particularly suitable for this purpose. To achieve this aim the choice of training system also holds a key role; in fact some training systems prove more suitable for HDP than others. In 2006, an experimental orchard was set up in the vocational area of Ferrara, with the goal of comparing different training systems suitable for the most important Italian cultivar ‘Abbé Fétel’. ‘Abbé Fétel’ was grafted on several rootstocks (Adams, Sydo®, BA29, MC, MH®, and BH-MC), and trained to the following systems (spindle, vertical axis, V system, very intensive V system (only on MC), or double axis (Bi-axis)), with planting densities ranging from 2,857 to 9,524 trees/ha. The first results (2008) underlined an early bearing of the orchard and yield differences according to the training system, with the very intensive V system and the vertical axis the most productive systems (36 and 31 t/ha, respectively). These results are due to the high density planting of these systems that enhances early bearing more than in the others. MC was the rootstock that provided the highest average yield during the first year (31 t/ha), while BH-MC the lowest (17 t/ha). In 2009, in general, average yields decreased for all the systems due to environmental conditions, but however the vertical axis stood out for its highest average production (21 t/ha), while the Bi-axis halved its yield with respect to 2008. Among the rootstocks, Adams contributed to the highest average yield (18 t/ha), but was not statistically different from the other rootstocks. In the first two years of data, Abbé Fétel on MH® trained to bi-axis emerged as the combination that supplied the highest percentage of fruit over 70 mm (around 83%) with an average fruit weight of 323 g in 2008 and 355 g in 2009. But in 2010, ‘Abbé Fétel’ grafted on MH® and trained at vertical axis and Bi-axis reported a considerable decrease in %or fruits over 70 mm. At the 5th year, Sydo® and BA29 registered the best performances in terms of fruit size (>85%).