THE EFFECT OF FLOWER AND FRUIT THINNING ON THE FIRMNESS OF COX ORANGE PIPPIN APPLES AT HARVEST AND AFTER STORAGE

In two out of three years the removal of all but the first axillary flower or fruitlet 5 or 37 d after full-bloom, respectively, increased the firmness of 'Cox' apples at harvest and after storage in 1.25% O2 (< 1% CO2) at 3.5-degrees-C. Thinning 19 d after full bloom did not increase firmness. Firmness increase in fruit from thinned trees was accompanied by higher dry matter and P concentration in the fruit at harvest. Fruits from thinned trees were larger, less dense and contained more K and less Ca than those from unthinned trees. Thinning tended to increase susceptibility to physiological storage disorders.