Relationship between light microclimate, fruit growth, fruit quality, specific leaf weight and N and P content of spur leaves of ‘Bartlett’ and ‘Anjou’ pear

Abstract

Hemispherical photography was used to measure the light microclimate surrounding fruiting spurs of ‘Bartlett’ and ‘Anjou’ pear ( Pyrus communis L.) and to relate the percentage of sky visible in the photograph (% sky) to fruit growth patterns and fruit size and quality at harvest. Each cultivar responded differently to the variation in % sky within the spur microclimate. Fruit size and concentration of total soluble solids at harvest of ‘Anjou’ was positively correlated to % sky. For ‘Bartlett’, fruit firmness and concentration of total soluble solids at harvest were positively correlated to % sky, whereas two components of fruit color, hue angle and chroma, were negatively correlated to % sky. Spur leaf N on an area basis was positively correlated to % sky and spur leaf P on a dry weight basis was negatively correlated to % sky for both cultivars. There were no consistent relationships between the N and P status of spur leaves and any measures of fruit quality. For the 3 years of the study, the number of blossom clusters of ‘Anjou’ was positively correlated to % sky the previous summer.