2001 AACC Annual Meeting Charlotte, North Carolina October 14-18, 2001 Charlotte Convention Center

Hard, vitreous kernel (HVK) count is an important measurement in determining the following US grade sub-classifications for durum wheat: Hard amber durum (75 to 100% HVK), amber durum (60 to 74% HVK) and durum (<60% HVK). Pre-harvest rains can reduce the apparent vitreousness of durum wheat kernels, which can lower the grade and value of a crop. The objective of this research was to compare two visual methods for determining hard vitreous kernel count. One method assesses the surface of whole kernels (most common), while the other assesses the cross-sections of dissected kernels. Durum samples (775) collected at harvest during the 1997 to 2000 crop years were analyzed for HVK using both visual methods. Results indicated that in years when harvest was delayed by rain, samples that appeared opaque on the surface were often found vitreous upon dissection. In three of the four years, a substantial number of samples assessed by the kernel surface method were graded into lower sub-classifications than if they had been analyzed by the cross-section method. In the fourth year, a number of samples were graded higher using the kernel surface method compared to the cross-section method.