The quality characteristics of ‘Royal Gala’ apple, presented as the
trait means from nine storage interval assessments, were significantly
influenced by both the timing and intensity of early-season
crop thinning, typically used to set tree crop loads for determining
fruit size (Tables 1–3). Unthinned control trees had fruit numbers
2.5 times greater than the highest crops set by crop load treatments,
which contrast analysis showed was associated with significantly
lower FF, SSC, TA and DMC as well as smaller fruit size. With ‘Cox’s
Orange Pippin’ apple, Johnson (1992) similarly concluded that all
thinning treatments significantly increased fruit size, post-storage
FF and DMC when compared with no thinning. Two aspects of
fruit storage metabolism showed contrasting trends: weight loss
by fruit from unthinned controls was not different, whereas starch
hydrolysis was significantly more rapid than in all other crop load
treatments. The characteristics of fruit from these unthinned trees
with a naturally set very high crop load quantify the genotypic
expression of fruit quality traits seldom defined or available to use
in interpretation of effects of tree management on storage fruit
quality