Measurement of nut dimensions
L. J. Grauke
Routine measurement of pecans should include length, width, and height of nuts. In the past, samples in the Breeding Program have been measured for "width at the widest point", and have failed to distinguish nut width from height. Figure 1, below offers guidelines for measuring the parameters.
It should also be noted that every nut has an upper (adaxial) and lower (abaxial) surface. Some cultivars, such as 'Success' and 'Wichita', have very assymetric apical lobes, making distinction easy. The orientation of the nut in the shuck dictates its abaxial and adaxial surfaces, as diagrammed below.
When photographing the samples, be sure the adaxial surface is "up" in the picture, and the abaxial surface is "down".