Abstract
1. With 3-year-old Muscat of Alexandria grapes grown in pots under vinyl film shelter, the effect of night temperature on the berry growth, yield and quality was observed. Vines were kept at night (6 p.m. to 8 a.m.) in the controlled temperature chambers of 15°, 22°, 28° and 35°C respectively, only for one growth period of shoot elongation (27 days), berry enlargement (20 days) and berry maturity (20 days).
2. In the treatment at the shoot elongation stage, all flower buds shed down at 35°C before blooming. In the treatment at the early stage of berry enlargement, both the berry growth and yield at harvest were the worst at 35°C. Berry shape was almost round at 35°C, and oblong at the lower temperatures than 28°C.
3. From the various standspoints, 28°C was the best temperature at any stage of the growing season. The higher or the lower the treating temperature than 28°C, the more inferior the berry growth, yield and quality. The similar relation existed also between the temperature and pollen germination, showing the highest germination per cent at 28°C.
