IMPROVED TRAINING AND PRUNING TECHNIQUES INCREASED PRODUCTIVITY OF 'ROCHA' PEAR

Abstract

‘Rocha’ pear yield has been improving steadily in the last decades, through intensification and refinement of cultural practices. Three orchards P1 (2700 trees ha-1), P2 (3600 trees ha-1) and P3 (5400 trees ha-1) were planted in 2004, 1999 and 2004, respectively, to determine the adaptability of ‘Rocha’ pear to high density producing models. During four years an experiment was conducted to study the effects of alternative training (P1 and P3) and pruning techniques (P2). Three training treatments consisted of alternate axis-tilt angles of 0, 12 and 17° in orchard P1 and 0, 5 and 10° in orchard P3. Pruning treatments consisted of three levels of pruning intensity (non-pruning, light and severe pruning). Extensive measurements were done in the soil, plant and atmosphere. Emphasis was on the light environment, using a ceptometer, net photosynthesis, light and CO2 response curves of individual leaves, using an IRGA, biomass partitioning, fruit growth and quality and final yield. ‘Rocha’ showed very good adaptation to high-tree density. The four-year average productivity of P1-orchard increased with axis-tilt; it was respectively 52.9, 62.5 and 70.0 t ha-1. The four-year average productivity of P3-orchard was higher for the higher axis tilt (86.2 t ha-1), but there was no improvement with axis-tilt in the other cases. Pruning treatments resulted in productivities of 77.1, 106.6 and 105.7 t ha-1 for non-, light and severe pruning. Both tilt angle and pruning intensity increases resulted in higher fruit grades due to a significant positive effect on fruit growth. Axis-tilt increased PAR interception and photosynthetic rates, mainly deep inside the canopy. At solar noon, the fraction of intercepted PAR exceeded 60% in the most effective treatments, 10% more than 0° tilt trials. ‘Rocha’ pear has shown high yield potential, and productivity and fruit quality increased with appropriate combination of planting density, training and pruning techniques.