Search Results
You are looking at 1 - 3 of 3 items for :
- Author or Editor: E.F. Young Jr. x
- Journal of the American Society for Horticultural Science x
The Munsell Color System was used to define pecan [Carya illinoinensis (Wangenh.) K. Koch] kernel colors and color changes for 21 clones, 11 locations, and 4 storage methods for nuts collected over a 4-year period. Hue readings ranged from 10.0 (10 red) to 22.5 (2.5 yellow). Value readings ranged from 2.5 to 8.0, and chroma readings ranged from 1.0 to 8.0. A total of 91 color chips (individual combinations of hue, value, and chroma) were needed to describe kernel color variability. In 1987 and 1988, one color [15.0/5/4 (hue/value/chroma)] accounted for 3,979 of the 32,078 readings taken, and the 15 most common colors accounted for 80.7% of all the readings. The Munsell system of color determination was well suited for pecan color determinations. A simplified color rating system with only six color classes was developed for general use by the pecan industry. This system is also routinely used in our breeding and genetics program to define this very important quality trait in pecan.
The Munsell color system was used to study kernel color differences between four pecan [Carya illinoinensis (Wangenh.) K. Koch] cultivars (`Cheyenne', `Choctaw', `Western', and `Wichita') grown at four locations (Tulare, Calif., and Brownwood, Crystal City, and El Paso, Texas) during two seasons (1987 and 1988) and stored under different temperatures (20 to 24 °C and -5 °C). Kernel color changed over time from yellow to red hues and from lighter to darker values, but changed very little in chroma. Initial ratings of each color attribute by cultivar were positively correlated with patterns of change in that attribute over time. Kernels collected in 1987 were more yellow and had greater color saturation than kernels collected in 1988. `Cheyenne' kernels 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 than unfrozen kernels, but could not be distinguished on the basis of value (lightness). Kernels frozen 12 months had reduced chroma compared to those frozen 6 months or unfrozen. Shelled kernels of `Wichita' changed hue more in storage than kernels of other cultivars. Shelled kernels held at 20 to 24 °C became darker and developed red coloration quicker than unshelled pecans. Variation in hue and value accounted for the majority of color difference between cultivars. Changes in hue accounted for the majority of color change over time. Differences among cultivars in value (lightness) were consistent over time.
Abstract
Results are presented for performance of pecan [Carya illinoinensis (Wangenh.) C. Koch] clones at six established National Pecan Advanced Clone Testing System (NPACTS) sites for 16 nut quality factors from 1980 through 1985. Total nut weight and percent kernel were significantly greater at Tulare, Calif. than at any other location, with ≈80% of the clones averaging 6.5 g/nut or more and ≈90% averaging at least 54.5% kernel. Nut weight was smallest at El Paso, Texas. Daily mean temperatures during nut expansion may be a major factor determining nut weight response. Low nut density was characteristic of more clones at Baton Rouge, La. than at any other location. Kernel color was lightest at El Paso and darkest at Baton Rouge, with darker color appearing to be related to high field moisture conditions before harvest. Nut weight was not related to kernel percentage, color, or percent kernel covered with fuzz (packing material); thus, large nuts are not necessarily of lower quality and can be selected in an effective breeding program. Amount of nut “packing material” retained in the sutures of kernel halves after shelling was generally not related to other traits, except that material retained in ventral grooves increased with nut and kernel weight. Depth and width of dorsal grooves were not related to retention of packing material and can be disregarded in future pecan nut evaluation systems. Many other expected character relationships were verified and the overall NPACTS nut evaluation system will be revised based on these results.