Respiration Studies of Developing Jonathan Apples

1.The size of fruit.The smaller fruits would have a greater surface area per unit of weight which imay facilitate gaseous exchange.2. The comparative penetrability of the skin (stomata and lenticels) as the fruits develop.3. The composition of individual fruits, wlhich mlay be affected by tem- perature, exposure to light, number of fruits per spur, and number and size of spur leaves.4. The number of fertile seeds per fruit. Materials and methodsThe Jonathan apples used in this study%+ were grown in the Brigham YoungIUniversity Orchard, Provo, Utah.The experim'iental frutits were thinned onie to each spur, and the leaves were also thinned in such a manner that each spur lhad approximately the samiie leaf area.All experimental spurs were located on the periphery of the tree buit there was considerable variation in exposure, that is, spiiris were used fromii all four sides of the tree.In the selection of apples for respirationi determiniationis, an effort wvas miiade ISo