Carbohydrate reserves are major substrates for cold hardiness and respiration during winter and for early growth during the following season for most woody plants. In apple, carbohydrate reserve accumulation occurs mainly in late summer and autumn as temperature and photoperiod decrease. However, information on the response of reserve carbohydrate accumulation and photosynthate partitioning into sorbitol, sucrose, and starch in apple to decreasing temperature and photoperiod is limited. One-year-old `Gala' apple plants were grown in controlled environments at 26 °C and 16-h photoperiod for 50 d and then either remained in 26 °C/16 h or were subjected to a lower temperature and shorter photoperiod for 28 d that resulted in four treatments of 26 °C/16h (HT/LD), 26 °C/8h (HT/SD), 13 °C/16h (LT/LD), 13 °C/8h (LT/SD). Newly fixed 14C-photosynthates and reserve carbohydrates were analyzed in leaves, stems, and roots. Leaf photosynthesis and plant growth parameters were also examined. The LT treatments inhibited plant shoot growth and leaf initiation rates while SD treatments had little additive effect. Plants with LD treatments had greater specific leaf weight, but decreased photosynthetic rates compared to SD regimes. A decrease in temperature altered partitioning of newly fixed 14C-photosynthates into sorbitol, sucrose, and starch and carbohydrate accumulation in various plant organs. Low temperature effects were modified by photoperiod.