Pecan Variety Observations
J.P.OVERCASH*
IN THE POMOLOGY COURSES at Mississippi State University, students have laboratory exercises on the identification and study of pecan varieties. In the spring of 1967, a group of 11 students studied 29 varieties from the 1966 crop and the data they recorded are shown in Table 1.
The samples were obtained from Agricultural Experiment Station personnel, Agricultural Extension workers and private growers in several pecan-growing states. Eight states were represented by the samples in this study: Alabama, Arkansas, Florida, Georgia, Mississippi, North Carolina, Oklahoma and Texas. Eight of the varieties were represented by more than one sample; they were
Schley and Stuart-4 samples each; Desirable and Success --- 3 samples each; Cape Fear, GraKing, Pabst, and San Saba Improved --- 2 samples each. The nut samples were collected by the growers and other cooperators shortly after harvest, and mailed to State College, Mississippi. They then were placed in coded paper bags and stored in a refrigerator at 43 degrees F. until the pomology laboratory studies in March, 1967. The author expresses gratitude for the cooperation of the many contributors who furnished the nuts for this study.
Measurements were made of a representative sample of each variety. The length and width were measured with calipers in centimeters. Nuts per pound were calculated from the weight of 10-nut samples. These 10-nut samples of each variety were then cracked using a hand-operated Inertia Nutcracker furnished by the IMP Nutcracker Co., 4214 Hamilton Road, Columbus, Georgia. The shells were not wet, or pretreated, before cracking. The kernels and shells were separated by hand and the percentage "shell out” of kernels was determined by weight in grams. The number of complete halves was recorded for each sample and the percentage calculated, based on 20 halves.
Three factors in kernel quality were scored for each sample by each student and the averages appear in Table 1.These data reflect an average of the ratings given by all students and may be more variable than the results would have been if an experienced organoleptic(taste)panel of experts had been used.
The small number of samples of each variety (in most cases only one) eliminates comparisons of variations due to years, states or areas of production. Differences are pronounced in many cases and reflect characteristics of the varieties under study. Differences in nut and kernel size and shape for 12 varieties may be seen in figures 1 and 2. Other studies representing years and varieties, as well as areas of production, are underway and the results will be published subsequently.
Size of Nuts
The number of nuts per pound varied from 36 for the Nelson variety to 111 for Patrick. Nugget at 89 and Curtis at 80 nuts per pound were among the small varieties. Varieties in the large class(less than 50 per pound) were Nelson, Choctaw, Comanche, Desirable, GraKing, Hess, Mahan, Mohawk, Stuart and Western. There was an average of 57 nuts per pound for the 29 varieties.
Length and width measurements of nuts were recorded in centimeters and were somewhat related to weight. Nuts with a length greater than 4.5 cm. (1 and
3/4 inches) were Nelson 5.6 cm., Mahan 5.8 cm., Texhan 5.0 cm., Wichita 4.9 cm., GraKing 4.8 cm. and Mohawk 4.7 cm. Varieties with a diameter of 2.5 cm. (one inch) or more were Burkett, Choctaw, Comanche, Elliott, GraKing, Mohawk, Nelson, San Saba Improved and Success.
Nuts of the varieties Patrick and Nugget had the smallest width and length as well as the largest number of nuts per pound. They were introduced for public
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*Professor of horticulture, Mississippi State University, State College. Published in Mississippi Agricultural Experiment Station Journal No. 1626.
Fig. I. Typical nuts of 12 varieties of pecans. Photo image is about three-fourths natural size.
Fig. 2. Typical pecan kernel halves of 12 varieties. Photo image is about three-fourths natural size.
propagation for production for the 'shelling trade' in Oklahoma because of their excellent kernel characteristics. The results of this study point out some of their desirable qualities in this respect.
Shelling Characteristics
Two factors of extreme importance to pecan shelling plants are the percentage recovery by weight of kernels from the shelling operation and the percentage of the nuts, by number, which yield complete halves under commercial shelling practices.
The best percentage ‘shell out' was for the Patrick variety at 62 percent. This variety had thin, light-weight shells and plump, high-density kernels. Other varieties ranging downward from 62 percent were: Schley, Wichita, Curtis, Nugget, and Schley. Only six varieties had less than 50 percent 'shell out' of kernels. They were Barton, Moneymaker, Moore, Nelson, Ownes and Pabst. The average was 54 percent for all the varieties studied.
The varieties which yielded 20 complete halves (100 percent) were: Clark, Comanche, Mahan, Major, Moneymaker, Nugget and Owens. The lowest percentage of complete halves was for the Western at 50 percent. This characteristic as recorded in these studies was undoubtedly influenced by cultural conditions, storage, and variety as well as the technique of the students.
Table 1. Nut characteristics of pecan varieties from several locations in the pecan belt.
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'Shell out'
'In shell' measurement characteristics Kernel characteristics
Nuts Color Attract. Flavor
Per Length Width % % 5-lightest 5-best 5-best
Variety lb. cm. cm. 'shell out' halves 1-darkest 1-poor 1-poor
Barton 58 4.4 2.3 46 80 3.1 2.9 2.1
Burkett 52 3.4 2.7 52 75 2.7 1.8 2.4
Cape Fear 55 4.0 2.3 58 92 3.8 3.9 4.0
Choctaw 49 4.1 2.6 52 60 3.4 3.4 3.4
Clark 58 3.8 2.2 52 100 4.4 4.8 3.9
Comanche 44 3.5 2.8 59 100 3.6 3.3 3.3
Curtis 80 4.2 2.0 60 95 3.1 2.9 2.5
Delmas 61 4.4 2.3 50 85 1.6 1.6 1.9
Desirable 47 4.5 2.4 55 93 3.1 3.3 2.6
Elliott 61 3.4 2.8 54 90 4.2 4.1 3.7
GraKing 44 4.8 2.5 53 82 1.9 2.2 1.7
Mahan 44 5.8 2.2 59 100 3.5 3.3 3.3
Major 62 3.4 2.3 55 100 2.6 2.8 2.9
Mohawk 44 4.7 2.5 57 95 3.4 4.1 2.9
Money-
Maker 60 3.4 2.2 48 100 2.9 3.2 2.2
Moore 76 3.5 2.0 48 100 4.0 3.9 3.5
Nelson 36 5.6 2.5 39 80 2.8 2.8 2.2
Nugget 89 3.5 1.8 60 100 2.7 3.4 2.7
Owens 52 4.3 2.4 45 100 3.3 3.7 1.6
Pabst 54 4.0 2.1 47 72 2.7 2.7 3.2
Patrick 111 3.2 1.6 62 90 3.8 3.5 3.0
San Saba
Improved 68 4.2 2.7 59 92 3.1 3.3 2.9
Schley 55 4.2 2.1 61 94 3.7 3.9 3.0
Stuart 48 4.0 2.4 53 90 3.2 3.9 3.1
Success 53 3.8 2.7 54 82 3.1 3.1 3.6
SunniGlo 44 4.5 2.4 53 60 3.1 2.9 2.8
Texhan 55 5.0 2.2 57 85 3.1 2.6 2.7
Western 48 4.5 2.2 60 50 3.0 2.8 3.1
Wichita 60 4.5 2.2 61 85 3.8 4.1 2.9
PROCEEDINGS TEXAS PECAN GROWERS ASSOCIATION 71
Kernel Characteristics
Organoleptic judgments were made covering color, attractiveness (general appeal to each student) and flavor. Pecan kernels of a lighter color or shade of tan are considered especially desirable as varieties processed for sale as kernels. These same characteristics are also desirable for the ultimate consumer of the ‘in shell' pecan trade.
The 8 varieties in which the kernels were judged lightest by the students were: Clark, Elliott, Moore, Cape Fear, Patrick, Wichita, Schley and Comanche. The varieties with the darkest kernels were: Delmas, GraKing, Major, Burkett, Nugget and Pabst. Scores ranged from 1.6 (darkest) for Delmas to 4.4(lightest) for Clark. The median was 3. 1.
Attractiveness, or appeal to the student, was governed by a combination of factors such as uniform tan color, uniformity of shape and size of kernels and personal preferences. The ranks from first to eighth place were Clark, Elliott, Mohawk, Wichita, Cape Fear, Moore, Schley and Stuart.
Flavor is generally an expression of individual preference and wider differences were recorded between students for this factor than for either color or attractiveness. Nevertheless, there is validity in group judgment. The five varieties judged most desirable for flavor were Cape Fear, Clark, Elliott, Success and Moore.
Attention of pecan growers is called to the fact that these nut samples were collected over a large portion of the pecan belt, in some cases the orchards where the nuts were produced were as much as 1200 miles apart. The characteristics studied here are valid for these samples. Some of the variations were probably due to location and cultural practices but most of the differences can be attributed to varieties. Growers should select varieties on the basis of nut characteristics such as size, shape, color, flavor, or percentage ‘shell out' as well as characteristics such as vigor, growth habits, length of juvenility, yields, resistance or susceptibility to insects, diseases, nutritional disorders and the length of growing season required to mature the nuts.
The author is indebted to the students for their serious study of the varieties available. The students were very impressed by the wide diversity of nut characteristics available to growers.