RELATIONSHIP BETWEEN LIGHT MICROCLIMATE, FRUIT-GROWTH, FRUIT-QUALITY,SPECIFIC LEAF WEIGHT AND N-CONTENT AND P-CONTENT OF SPUR LEAVES OF BARTLETT AND ANJOU PEAR

Hemispherical photography was used to measure the light microclimate s urrounding fruiting spurs of 'Bartlett' and 'Anjou' pear (Pyrus commun is 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 o f fruit color, hue angle and chroma, were negatively correlated to % s ky. Spur leaf N on an area basis was positively correlated to % sky an d spur leaf P on a dry weight basis was negatively correlated to % sky for both cultivars. There were no consistent relationships between th e 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' w as positively correlated to % sky the previous summer.