VARIABILITY IN MATURITY, QUALITY AND STORAGE ABILITY OF JONAGOLD APPLES ON A TREE

We found that the variability in maturity and quality at a certain picking date of Jonagold apples on the same tree is very important. Data are given on the variation in starch content, firmness, green-yellow skincolour, Brix value and fruit weight. The variability in maturity makes it necessary to pick at different times. The quantity to be picked at each picking time varies between 2.5% (1st picking time), 25.7% (2nd), 42.4% (3rd), 22.4% (4th) and 1.9% (5th). Values of indices are given to determine optimum maturity characteristics at each picking time. For the first picking time a starch content of 50–60% dark surface with a firmness greater than 7.5% lbs (0.5 cm) is important. At the last picking time the optimal picking occurs at an optimum starch content of 40–50% dark surface and a sufficiently green ground colour (lower than 7). In literature some interpretation is given of the variability in maturity of the Jonagold apples on a tree.