The potential for commonly measured at-harvest fruit characteristics to predict chilling susceptibility of ‘Hort16A’ kiwifruit

Abstract

The propensity for physiological disorders to arise during low temperature storage of kiwifruit is a significant commercial risk. The potential to use fruit characteristics (flesh colour, soluble solids content (SSC), dry matter and firmness) estimated non-destructively at harvest as markers for the susceptibility of ‘Hort16A’ kiwifruit to chilling injury (CI) has been investigated for individual fruit. While the fruit that developed CI during storage were some of the least advanced fruit on each orchard, the flesh colour, SSC, firmness and dry matter of the susceptible fruit differed considerably among orchards, such that there was not a clear minimum or maximum threshold for which fruit did or did not develop CI across all orchards. There was a large ‘orchard factor’ in the susceptibility of fruit to CI that was as important, if not more important, than the flesh colour, SSC, firmness and dry matter values. The ‘orchard factor’ may derive from a combination of environmental conditions and/or orchard management practices, in conjunction with fruit growth and development. Hence it is concluded that a generally applicable at-harvest prediction of ‘Hort16A’ fruit susceptibility to CI is not possible from an at-harvest non-destructive estimation of flesh colour, SSC, firmness and dry matter.