Effe-gi, Magness-Taylor, and Instron Fruit Pressure Testing Devices for Apples, Peaches, and Nectarines1

Abstract

Abstract Pressure test values obtained on various fruits with 2 manual fruit pressure testers (the Magness-Taylor and the smaller Effe-gi) and the Instron Universal Testing Instrument were compared. Tests were made on 5 apple, 1 nectarine, and 3 peach cultivars on an individual fruit basis. Differences in pressure readings were marked among instruments. Responses to the instruments differed among cultivars. Some apples were classified in different ripeness categories according to different pressure testers. For nectarines and peaches, high correlations, but not complete agreement, were obtained among instruments. For all 3 fruits, differences were sufficient to require specification of instrument and method of measurement when fruit pressure test values are reported and to necessitate compensation when measurements made with different types of instruments are compared. Regression equations such as we report should be used to permit accurate comparisons.