A pot experiment was conducted in a tropical mid-elevation environment (861 m altitude) to evaluate sweetpotato (Ipomoea batatas (L.) Lam.) clones of different origin and breeding intensity for traits related to growth phenomena, nitrogen-use efficiency, and transpirational water-use efficiency (WUE) as affected by different levels of N fertilization. Genotypes with small canopies were associated with a consistently positive response in their final storage root dry matter (DM) yields to increasing N supply, and with efficient allocation of DM and N to storage roots. Genotypes with high canopy net assimilation rates (NARs) had a high proportion of leaves exposed to the sun and high chlorophyll content in leaves. Nitrogen stress led to increased transpiration per unit leaf area and decreasing WUE. Decreasing WUE under N stress was due to lower total plant DM production rather than to increased total water transpiration per plant.
Authors: M. Kelm, Michael Hermann, B. Sattelmacher, H. Brack, M. Kelm, Michael Hermann, B. Sattelmacher, H. Brack
Contributors: Administrator, Administrator
Subjects: Agronomy
Publisher: International Potato Center
Publication Date: 2001
Keywords: Net assimilation rate, Nitrogen, Water use efficiency
HOW TO CITE
Kelm, M., Brück, H., Hermann, M. and Sattelmacher, B. 2001. Plant productivity and water use efficiency of sweetpotato (Ipomoea batatas) as affected by nitrogen supply. CIP Program Report 1999–2000, pp.273-279.