Postdoc USDA-ARS, University of Illinois Urbana-Champaign
Disclosure: Disclosure information not submitted.
Optimizing crop canopies to improve light absorption and CO2 assimilation is among the strategies often cited to increase yield and meet the needs of a growing population by 2050. Because most of population increase is expected to occur in the Sub-Saharan Africa and because of the yield gap currently present there, it is crucial to develop high yield crops that are pertinent for this region. In this study, we screened 50 cowpea (Vigna unguiculata (L.) Walp) lines from the MAGIC population for canopy architectural traits as well as canopy photosynthesis and water-use efficiency using a canopy chamber in order to improve our understanding of the relationship among those traits. Canopy architecture contributed 38.6% of the variance observed in canopy photosynthesis. Results suggest that the light environment within the canopy was a limiting factor in the canopy CO2 assimilation. Indeed, traits favoring greater exposure of leaf area to light such as the width of the canopy relative to the total leaf area were associated with greater canopy photosynthesis, especially in canopies of high biomass. The canopy photosynthetic activity was a strong predictor of the canopy water-use efficiency and, therefore, the canopy architecture, indicating that optimizing the canopy will also contribute to improve the canopy water-use efficiency in the MAGIC population.