Sweet Potato Canopy Architecture: Branching Pattern

Abstract

The effect of the plant density (15, 30, 45 × 96-cm spacing) on the branching pattern `Jewel' sweet potato [Ipomoea batatas (L.) Lam.] was determined bi-weekly for 18 weeks. Plant density effects were significant for the number of branches formed and timing of branch formation. Plant density did not affect the type of branches formed (e.g., primary, secondary, and tertiary), but did alter the timing of induction during the growing season. By the end of the growing period, the ratios for the number of primary to secondary branches were 1.5:1, 1.3:1, and 0.6:1 at the 15-, 30-, and 45-cm spacing, respectively. Few tertiary branches were formed, but were present on some plants at each spacing. Tertiary branches most commonly occurred on plants at the widest spacing. While the number of branches per plant was highly plastic and inversely related to plant density, nodes per branch and internode length were not significantly affected. Average internode length per branch decreased with descending branch hierarchy (i,e., main stem < primary branch < secondary branch). `Jewel' sweet potato responded to increased space available largely through production of additional branches with the modification of branching pattern increasing as the season progressed.