Root and Shoot Growth Patterns of Newly Rooted Woody Plants

Abstract Changes in primary root number (RN), root dry weight (RDW), and shoot dry weight (SDW) on newly rooted stem cuttings of 7 woody ornamental plants were evaluated over 18 or 24 weeks after either no root removal or root removal where remaining RN equalled 25%, 50%, or 100% of the average RN at transplanting. Regardless of root removal treatment or season (February, June, or July), increases in primary RN occurred after transplanting and preceded increases in RDW and SDW. RDW and SDW increased progressively and together after primary RN ceased increasing. Cuttings started in February attained maximum RN in 12 to 18 weeks after transplanting, whereas those started in June and July required 6 weeks. Results suggest that stem cuttings of woody plants have a minimum, species dependent, primary RN which must be attained before measurable shoot growth is initiated.