THE EFFECT OF YEAR, CULTIVAR, LOCATION, AND STORAGE REGIME ON PECAN KERNEL COLOR

The Munsell color system was used to study kernel color differences be tween four pecan [Carya illinoinensis (Wangenh.) K.Koch] cultivars ('C heyenne', 'Choctaw', 'Western', and 'Wichita') grown at four locations (Tulare,Calif., and Brownwood, Crystal City, and El Paso, Texas) duri ng two seasons (1987 and 1988) and stored under different temperatures (20 to 24 degrees C and -5 degrees C). Kernel color changed over time from yellow to red hues and from lighter to darker values, but change d very little in chroma, Initial ratings of each color attribute by cu ltivar were positively correlated with patterns of change in that attr ibute over time. Kernels collected in 1987 were more yellow and had gr eater color saturation than kernels collected in 1988, 'Cheyenne' kern els were the most yellow of the cultivars tested and 'Wichita' kernels were the most red. 'Cheyenne' kernels were lighter than those of any other cultivar, Kernels frozen 6 or 12 months were more red in hue tha n unfrozen kernels, but could not be distinguished on the basis of val ue (lightness), Kernels frozen 12 months had reduced chroma compared t o those frozen 6 months or unfrozen. Shelled kernels of 'Wichita' chan ged hue more in storage than kernels of other cultivars, Shelled kerne ls held at 20 to 24 degrees C became darker and developed red colorati on quicker than unshelled pecans. Variation in hue and value accounted for the majority of color difference between cultivars. Changes in hu e accounted for the majority of color change over time. Differences am ong cultivars in value (lightness) were consistent over time.