Relationship between crop load and fruit quality in low-chill peaches and nectarines

Fruits from low-chill peach and nectarine cultivars have lower quality in comparison with traditional varieties. One of the factors that most affect both fruit quality and fruit yield is the crop load (CL). The objective of the present work was to evaluate the relationship between CL and the external and internal fruit quality of low-chill peaches in a temperate-subtropical transition zone of the central-east region of Santa Fe province (Argentina). Fruit diameter (mm), total soluble solids (degrees Brix), titratable acidity (%), juiciness (%), skin red over-colour (%) and the Commission Internationale de l'Elcairage (CIE) colour parameters, and fruit yield efficiency (kg cm(-2) trunk cross-sectional area; TCSA) were evaluated in nine low-chill peach cultivars under three CL treatments: 1.0 (low), 1.5 (medium) and 2.0 (high) fruit cm(-2) TCSA. Increasing from low to medium CL did not affect the internal or external fruit quality attributes of any of the nine low-chill cultivars studied but increased fruit yield from 20% to 44% according to the genotype. In some cultivars, such as 'Don Agustin' and 'Lara', it was possible to increase the CL to 2 fruit cm(-2) TCSA without affecting fruit quality.