North Carolina Agricultural Research Service - 1989 Young, E. (1989). First-year shoot development and carbohydrate distribution in fall- and spring-planted apple trees. HortScience, 24(2), 234. Young, E. (1989). Cytokinin and soluble carbohydrate concentrations in xylem sap of apple during dormancy and budbreak. Journal of the American Society for Horticultural Science, 114(2), 297. Stuber, C. W. (1989). Marker-based selection for quantitative traits. Science for Plant Breeding : Proceedings of the XII. Congress of Eucarpia, February 27-March 4, 1989, Go?Ttingen, Germany F.R., 16, 31.