Fruit-Thinning Effects on the Development and Storage Quality of Cox’s Orange Pippin Apple Fruits

Abstract

SummaryFruit-thinning treatments were applied in the three seasons 1963–65 to Cox trees to investigate the relationships between leaf : fruit ratio, fruit size, cell volume and cell number, and the incidence of rotting and disorders following air storage at 2·8° C. (37° F.) and o° C. (32° F.). Progressively more severe thinning was required, sis fruit development proceeded, to obtain a similar increase in fruit size. This declining response to thinning was accompanied by a progressively smaller increase in the cell numbers of fruits as the treatments were delayed. Thinning also caused an increase in cell-enlargement rate but the magnitude of the response varied between different experiments and did not appear to be related to the developmental stage at which the treatment was applied.The larger fruits from thinned trees were more susceptible to bitter pit, breakdown, and rotting caused by Gloeosporium perennans, but were less susceptible to low-temperature injury than fruits from unthinned trees. Bitter-p...