Development of a Sampling Plan and Application of a Grading Scheme for Determining Apple Packout Losses

Abstract

Abstract A sampling plan was developed and used along with a modified grading scheme as a tool to predict apple (Malus domestica, Borkh.) fruit quality, thus providing a means to evaluate the impact of orchard management practices on market potential. Apple extra fancy/fancy packout was predicted to within 10% by examining a 100-fruit sample from each of five bins at the submersion tank. Packout loss factors were predicted to within 5% by sampling 100 fruit from each of four bins. A modified Russo/Rajotte grading scheme in chart format proved to be a useful tool for assessing packout losses. An evaluation of downgraded fruit, comparing the grading scheme to grower practice, yielded coefficients of determination ranging from 0.83 to 0.94 for five of six fruit lots sampled. The grower’s marketing intentions and the tendency of packinghouse staff to give more attention to the most obvious defects during grading influenced the ability to predict packout and the severity of loss factors.