|Reese, C. - SOUTH DAKOTA STATE UNIV|
|Clay, D. - SOUTH DAKOTA STATE UNIV|
|Beck, D - SOUTH DAKOTA STATE UNIV|
Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: July 29, 2004
Publication Date: October 31, 2004
Citation: Reese, C.L., Clay, D.E., Beck, D., Long, D.S. 2004. Using stable isotopes and crop reflectance to characterize water and nitrogen stress in hard red winter wheat. Agronomy Abstracts. Technical Abstract: Hard red spring wheat (Triticum aestivum L.) in the Great Plains is nitrogen (N) and water limited. A diagnostic tool for separating the effects of N and water stress on wheat yield is needed. Nitrogen and water stress are known to influence C^13 discrimination during photosynthesis. The objective of this study was to determine if C^discrimination could be used to assess the impact of water and N stress on wheat yield variability. Wheat was grown at seven different N treatments in the Northern Great Plains. N treatments were (a) 0, (b) 40, or (c) 80 kg ha^-1 pre-emergence, (d) 26 kg ha^ -1 pre-emergence and 54 kg ha^-1 at 5 to 6 leaf stage, (e) 54 kg ha^-1 at 5 to 6 leaf stage, (f) 80 kg ha^-1 at 5 to 6 leaf stage and (g) 13 kg ha^-1 pre-emergence, 54 kg ha^-1 at 5 to 6 leaf stage and 13 kg ha^-1 at flag leaf. Grain samples collected at harvest. Harvest samples were analyzed for yield, C^13 discrimination, and protein. Highest yield was obtained when 54 kg N ha^-1 was applied at the 5 to 6 leaf stage. C^13 discrimination decreased as pre-emergence N increased from 0 to 80 kg N ha^-1. Protein increased as N increased. Results suggest that C^13 discrimination can be used to access N and water stress in wheat.