Yield and Quality Response to N Fertilizer by Six Durum Wheat Varieties.

Grain protein in durum wheat is economically important and recommendations on late N application rates for protein premium are of interest to growers and industry. Yield prediction at anthesis is essential for appropriate N rate to reach 13% protein premium. A field trial with six durum wheat varieties were conducted in 2011 and 2012 growing seasons to study crop yield and quality response to six N rates. Five biomass samples were taken in each growing season to measure leaf area, biomass, and N accumulation in biomass. Remote sensing and SPAD meter reading were also taken and crop model DSSAT used for yield prediction and late N management at anthesis. Crop varieites differed in N uptake efficiency and N use efficiency. Spetral and SPAD readings at anthesis and crop model accurately predicted grain yield and can be used for late N management.