Judging kernels

   Over the past couple of weeks, I've been looking at a lot of pecan samples. We collected nuts from 216 trees in our pecan breeding plot and cracked 10 nuts from each tree. We evaluated those nuts for size, percent kernel, and kernel appearance. Nut weight and percent kernel are easy measurements to determine with the aid of a gram scale and calculator. However, when it comes down to kernel appearance things get a little more difficult to quantify.
   A smooth, golden kernel color is most desirable for pecan. Light-colored kernels are described by the official USDA pecan grading system as "Fancy". However, in evaluating hundreds of nut samples, my eye detects subtle color differences even among kernels that would be graded as Fancy. The photo at right demonstrates these subtle color differences. At the top are the lightest colored kernels I found among our breeding plot nuts. In the middle are kernels with a beautiful golden pecan color. The kernels at the bottom are ever so slightly darker than the ones above but still have a pleasing sandy coloration. Which looks best to you?

    Not all the nut samples we cracked had beautiful even-colored kernels. It is so disappointing to crack open a large, thin-shelled nut only to find an ugly pecan kernel inside. I found two types of kernel defects (photo at left). The first was the appearance of dark veins that cross the surface of the nut. The second was a mottling of the kernel surface with dark patches. I even found a tree that produced nuts with both veins and mottling. These kernel discolorations do not effect kernel taste but the lack of "eye-appeal" would make selling these types of kernels very difficult. 
    All nut samples from our breeding project will be on display during the KNGA annual meeting. Click on the event tab above for details.