The Physiology of Growth in Apple Fruits III. Cell Characteristics and Respiratory Activity of Light and Heavy Crop Fruits

Cell size, total and protein nitrogen, and preclimacteric respiration have been studied for light and heavy crop fruit of certain Tasmanian-grown apple varieties. Differences in size of fruit from light and heavy crops have been shown to be due mainly to differences in cell size rather than in cell number. Respiration per cell, protein nitrogen per cell, and cell volume were closely intercorrelated but respiration per unit protein is greater in light crop fruit than in heavy crop.