@article{whitworth_young_1992, title={CHILLING UNIT ACCUMULATION AND FORCING EFFECTS ON CARBOHYDRATES OF YOUNG APPLE ROOTSTOCKS}, volume={67}, ISSN={["0022-1589"]}, DOI={10.1080/00221589.1992.11516241}, abstractNote={Sucrose, glucose, hexose (glucose + fructose), and sorbitol were measured enzymatically in root and shoot tissues of young apple (Malus x domestica Borkh.) MM. Ill rootstocks during rest (0 to 2400 chilling units (CU) and 0 to 36 days of forcing (DF). Changes in starch and sorbitol concentrations during chilling and forcing were variable. Starch generally decreased with increasing chilling and forcing. Sorbitol showed little change with forcing. Sorbitol concentration generally declined until chilling was adequate for 50 to 90% budbreak (1200-1600 CU), then increased. The magnitude of changes was greater overall for starch in roots and for sorbitol in shoots. Sucrose and hexose concentrations in shoots and roots increased from 0 to 12 DF, remained relatively stable from 12 to 24 DF, and declined from 24 to 36 DF. Sucrose increased from 0 through 800 CU, decreased between 800 and 1200 CU (chilling requirement for 50% budbreak), and remained relatively stable from 1200 through 2400 CU. During rest, hexose d...}, number={2}, journal={JOURNAL OF HORTICULTURAL SCIENCE}, author={WHITWORTH, JL and YOUNG, E}, year={1992}, month={Mar}, pages={225–230} }