The Physiology of Growth in Apple Fruits IV. Seasonal Variation in Cell Size, Nitrogen Metabolism, and Respiration in Developing Granny Smith Apple Fruits

Results of investigation of cell size, fruit size, nitrogen metabolism, and respiration rate over three successive seasons confirm the main conclusions of earlier papers in this series. Fruit left on the trees for a period beyond normal commercial maturity showed a very -large increase in soluble nitrogen with only slight increase in protein nitrogen. The relation of the nitrogen and organic acid metabolism to the climacteric rise in respiration is discussed.