Assessment of Fruit Firmness in Selected Sour Cherry Genotypes

Abstract

Abstract Significant differences in firmness were detected when the Instron Universal Testing Machine was used to test fruit firmness in a group of 13 sour cherry (Prunus cerasus L.) cultivars and selections. Deformation testing of intact fruit resulted in the establishment of seven statistically distinct firmness groups. Selections and cultivars that were firmer than ‘Montmorency’ were identified. Differences in skin strength, as determined by an Instron puncture test, were not as distinct. At harvest, firmness was not correlated with soluble solids content, fruit removal force or fruit weight, indicating the inadequacy of any of these parameters alone as an index of fruit maturity. Deformation testing with the Instron can be used to accurately assess whole fruit firmness in sour cherry breeding programs. Modification of the puncture test would be required to increase the precision in detecting differences in skin strength.