IRCULAR 225 r NOVEMBER 19 Nut Quality of Selected Pecan farieties Grown inSouth Alabama 2RICULTURAL EXPERIMENT Dennis Rouse, Director STATION AUBURN UNIVERSITI Auburn, Alabamc CONTENTS Page EXPERIMENTAL PROCEDURES AND RESULTS ------------------------ 4 4 Procedures------------------------------------------------------------- Results---------------------------------------------------------------------DISCUSSION----------------------------------------------16 5 APPENDIX-----------------------------------------------18 Origin and Observations of Varieties and Selections --------18 FIRST PRINTING 5M, NOVEMBER 1975 Auburn University is an equal opportunity employer. Nut Quality of Selected Pecan Varieties Grown In South Alabama HARRY J. AMLING, KAREN A. MARCUS, JAMES E. BARRETT, and N. RONALD McDANIEL* RANKS THIRD in total pecan production among the Nation's pecan producing states'. Production is primarily from named varieties rather than seedlings. Varieties that contribute most to Alabama production are Stuart, Success, Schley, and Desirable. These varieties, chance seedlings introduced in the late 1880's and early 1900's, were considered immune or highly resistant to pecan scab when introduced and first planted. Since that time, however, specific physiological forms of the pecan scab fungus have developed - first with Schley and Success and in recent times with Stuart and Desirable - that dictate the use of fungicide applications to achieve commercially accepted crops. Success and Schley are no longer recommended for planting in Alabama. Success is unable to consistently fill nuts as trees grow older, even under intensive fertilizer and spray programs. Schley, although possessing a fine quality kernel, produces insufficient yields to justify further planting. For these reasons Success and Schley have been omitted from the present study. Four varieties are currently recommended in Alabama: Stuart, Desirable, Elliott, and Farley2 . A continuing pecan variety testing program was begun in 1960 to evaluate new selections and varietal releases in comparison with those currently recommended. New and more precocious pecan varieties available and intense cultural methods make possible higher yield per acre. * Respectively, Professor and Research Associate, Department of Horticulture, and Superintendent and Assistant Superintendent, Gulf Coast Substation. Agricultural Statistics. 1974. U.S. Government Printing Office, Washington, D.C. ALABAMA 'USDA 2BAGBY, JOHN. 1970. Pecan Production. Service, Auburn University. Cir. P-28. Cooperative Extension An objective of this testing program is to measure nut and kernel characteristics of pecan varieties and selections having potential for Alabama. This report presents results of these quality evaluations. EXPERIMENTAL PROCEDURES AND RESULTS Procedures Nut samples used for quality determinations were obtained from trees grown at the Gulf Coast Substation. These trees were maintained under a complete fertilization and disease, insect, and weed control program as recommended by Auburn University. Harvesting was accomplished primarily by trunk shaking and hand harvesting. Repeated harvests were required for most varieties, with first harvest made when approximately 30 to 50 percent of the shucks had split. Nut quality determinations were made on single-tree composite samples representing all harvests, using 1-pound samples where possible. Yearly data presented represent the average from all trees of a given variety or selection. Prior to evaluations, samples were cured at room temperature for 4 to 6 weeks until they had reached approximate constant weight. Nut volume represents average water displacement (cubic centimeters) per nut. This value was determined by measuring the cubic centimeters of water displaced by a nut sample and dividing by the number of nuts in that sample. Percent kernel was obtained by extracting the kernels, weighing the total kernel fraction, and dividing by the nut sample weight. Calculated percent fill is a measurement of the degree to which the interior volume of nut shell is filled by the kernel. These estimations were computed using standards and procedures described by Romberg. These procedures involved determining (1) nut volume, (2) shell weight per cubic centimeter of nut volume, and (3) kernel weight per cubic centimeter of nut volume. Shell weight per cubic centimeter of the sample was matched with a standard shell weight per cubic centimeter for 100 percent filled nuts to obtain the corresponding standard kernel weight per cubic centimeter for a 100 percent nut. This value was divided into sample kernel weight per cubic centimeter to give calculated percent estimates. The amount of space available for potential filling is the interior volume within the shell. L. D. 1952. Measurement of the Filling of Pecan Nuts. Proc. Texas Pecan Growers Assoc. 31:36-42. ROMBERG, [4] Theoretically, complete filling of this space by a developed kernel would result in 100 percent filling. This is not true, however, because kernel moisture contents change between developing and mature stages. Kernels are in a hydrated state when developing and filling the shell, but moisture losses during normal ripening of the nut prior to harvest causes a shrinkage of the kernel. The result is a fill less than 100 percent. Nuts having a calculated fill value of 75 percent and over were considered to be well filled. Nut density was obtained by dividing nut sample weight by nut sample volume as measured by volume of water displaced at total immersion. Average individual nut and kernel weights were determined by dividing the sample nut and kernel weight by the number of nuts in the sample. The number of nuts per pound was calculated by dividing the average weight of a nut in each sample into 454 grams and rounding the resulting figure off to the nearest whole number. The percent of nuts according to diameter was determined by measuring the diameter of each nut in a sample in 1/16-inch increments, and then calculating what percent of the whole sample each increment size represented. Length of each nut in a sample was measured to the nearest millimeter, then averaged. Results FIRST HARVEST. Eleven varieties and selections could be har- vested before Elliott, the earliest ripener of currently recommended varieties. The earliest was 48-15-3, Table 1. Fifteen could be harvested before Desirable. Stuart, Farley, and Hastings consistently matured their nuts later than all others. Varieties and selections were considered early maturing if the bulk of their harvest could be completed by October 1. Fitting this category were 48-15-3, Starking, Shoshoni, Cherokee, Chickasaw, Barton, Mohawk, Wichita, Caddo, 45-3-3, and 53-11-139. Midseason ripeners were considered those that could have the bulk of their crop harvested during October. Elliott, 61-4-35, GraBohls, 45-10-23, Shawnee, Cape Fear, 61-6-96, Cheyenne, Kernodle, Mahan-Stuart, and Desirable made up this group. Prior to this investigation Stuart was not considered a late maturing variety. However, in comparison with newer introductions it would now be so classified. NUTrr VOLUME. Mohawk had the largest volume and nut size, being considerably larger than Desirable, the variety currently [5]1 TABLE 1. DATE OF FIRST HARVEST OF VARIETIES AND SELECTIONS EVALUATION DURING THE PERIOD 1970-1974, GULF COAST SUBSTATION, FAIRHOPE Variety I~L U~CIICJI~ IIU~III~Lnr~ r r~~lrl J ~7 ~~Harvest dates 1-9 UNER 48-15--------------Starking --.----------------- --Shosh on i ---- ----- --------- ---- Cherokee--------.-------------- ---------------- Chickasaw Ba rto n -------- -------- ----- - - -- -- --- Mohawk.---------------------Wich ita ------- -- -- -- --- -- -- -- -- -- -_-_Caddo---------------- 45-3-3.-----------------------53-11-139--------------------------- ------- -- September September September September September September September September 7 17 27 27 27-October 1 27-October 1 28-October 1 Elliott-- - - - - - - -- - - - - - - -- - - - - - - -- - - - - - 61-4-35CraB ohis.------- -- ------ -----------45-10-23........................-------- ------Shawnee-------------- --- -------- --- September 28-October 1 October 1 October 1 October 1-9 October 6-14 October October October October October 7-14 Cape ----------------------- =- Y61-6-96 -. . . . . . . . . ..--------------------C heyenne Fear ----------------------- ---- Kernodle_---------------------------------M ahan-Stuart----------------------------------. Desirable...........---------------------S tuart - - - - - - - - - - - - - - - - - - - - - -_- - - - - Fa rle y -- - - - -- - - - - - - - - - - - - - - - - - - - - - - Hastin g s-- --- - - - - ---- - ------ - - - - - - -- 9-16 9-18 9-18 16 October 16-19 October 16-31 October 16-27 October 16-31 October 16-November 7 October 31-November 12 November 6-12 being used for giant mammoth halves, Table 2. Seventeen of the 24 varieties and selections evaluated had nut volume smaller than Stuart. Starking, 48-15-3, Chickasaw, and 53-11-139 had nut volumes smaller than Elliott. AMOUNT KERNEL. With the exception of Hastings, all varieties and selections evaluated had a higher percentage of kernels than did Stuart, Table 2. Mohawk, Kernodle, Wichita, Starking, 61-9-96, Shawnee, and Cheyenne averaged in excess of 58 percent kernel. CALCULATED PERCENT OF FILL. The ability of varieties and selec- tions to consistently fill nuts varied considerably, Table 2. Ker- nodle, Hastings, 45-10-23, Barton, CraBohis, 45-3-3, and Chickasaw appear to have the least capacity in this regard, whereas Shawnee, Shoshoni, Cape Fear, 61-4-35, Cheyenne, Wichita, Caddo, Elliott, Starking, and est degree of filling. NUT DENSITY. In general, the greater the nut density the higher the calculated fill. [6] Nut 48-15-3 consistently had the greatdensity varied among varieties, Table 2. TABLE 2. YEARLY AVERAGE MEASUREMENTS OF SELECTED NUT AND KERNEL CHARACTERISTICS OF PECAN VARIETIES UNDER EVALUATION AT THE GULF COAST SUBSTATION, FAIRHOPE Aon ac Variety and year Mohawk volume cc Aount alcukeofelatedl Pct. 6L.4 56.8 59.4 59.2 60.2 57.3 Pct. 85.1 69.0 74.3 76.2 75.7 77.9 65.1 Nut Nut niy' Nut eih Kernel wih Grams 0.782 .685 .715 .727 .721 .749 .641 .703 .542 .651 .575 .587 .588 10.9 11.9 12.2 11.7 11.0 11.7 Grams 6.7 6.7 7.3 6.9 6.6 6.7 5.3 6.2 4.4 4.3 4.6 4.4 4.4 6.1 6.1 6.0 5.5 5.9 5.5 5.8 4.7 5.6 5.4 5.1 5.1 3.7 4.6 5.1 4.4 4.4 5.3 4.8 4.2 5.6 3.3 4.4 5.3 ----13.9 -- 1973 .-------17.2 1974-------- --- 17.1 Average-.---____ 16.1 Kernodle 1971 ------------- 15.2 15.2--1972 .--- ------------- ---- 15.6 1973 .------------------ 13.7 Average--------------14.8 Hastings 1971---- ------- -----15.9 1972-------------------14.2 1973 ---- ------------------ 14.1 1974.--.----------------14.5 Average----------14.7 Mahan-Stuart 1971-------------- 13.3 1972----------------- 14.9 1973-------------------13.3 1974 ------------------- 13.9 Average. -------------- 13.9 Desirable ------------- 13.6 1971 ----1972 ------ --------------- 14.3 12.1 -----------------1973 -- 1972 60.6 59.4 72.9 46.7 57.0 10.5 8.8 8.6 9.2 8.1 8.6 50.6 46.4 56.0 51.6 41.2 59.0 53.6 60.5 54.7 57.0 53.6 51.6 54.6 53.1 53.2 55.5 54.1 52.8 54.1 47.6 46.2 50.3 30.3 48.6 53.2 53.6 51.1 52.6 61.1 [7] 54.0 52.7 52.6 83.3 76.6 79.7 72.2 78.0 75.1 80.5 68.7 78.9 75.8 68.2 67.7 57.4 64.4 74.4 75.2 68.3 80.1 74.5 61.7 75.0 51.1 62.6 79.0 8.6 10.4 .780 .756 .748 11.3 9.9 .720 .751 .747 .774 .703 .773 .749 .689 .705 .620 .671 .770 .781 .714 .800 .766 .651 .744 .577 .657 .741 10.0 10.4 10.3 11.3 8.5 10.6 10.2 9.2 9.5 7.0 8.6 10.7 9.5 8.8 10.6 9.9 7.8 10.4 6.4 82 8.6 1974 .----------------- 13.6 Average --------------------. 45-10-23 1971 -----------------Y-- 13.5 13.3 13.7 11.3 1972 -------------------------------------1973 12.8 Average --------------Stuart 19171 ------------- --- 13.9 12.1 1972 ---------------------12.3 1973 -----------------1974 ------------------- 13.3 ----- 12.9 Average Barton 1971 12.0 ------1972 1973 ------------ ---Average_----------------------. 14.0 11.1 12.4 61-6-96 1973------------------- 11.6 Continued -TAR KERNEL 2 (Con't.). YEARLY AVERAGE MEASUREMENTS OF SELECTED NUTS CHARACTERISTICS OF PECAN VARIETIES UNDER EVALUATION AT THE GULF COAST SUBSTATION, FAIRHOPE AND Variety and year vlm Nut Amount vouekernel of Calcu- lated Nut Nut Kernel weight fill' density2 weight cc GraBohls 19733 il 1974 -------------------- - 13.1 Average--------------12.1 Shawnee 1972 -- - - - --------- 11.3 --1973------------------10.7 1974.-------------------11.5 Average-------------- -11.2 Shoshoni 19733-----------------9.1 Pct. 55.9 58.9 57.4 Pct. 61.4 67.5 0.669 Grams .667 .668 .806 .747 .751 .768 .879 .740 .809 .779 .809 .700 .784 .768 7.5 8.7 8.1 9.1 8.0 8.7 8.6 8.0 9.5 8.8 8.3 9.7 6.9 9.4 8.6 7.8 8.9 7.5 7.9 8.0 9.3 6.7 8.0 7.4 6.9 7.4 7.3 7.7 8.6 Crams 4.2 5.1 4.7 5.9 4.7 4.9 5.2 4.1 5.2 4.7 4.8 5.1 4.0 5.1 4.8 4.1 4.5 4.1 4.4 4.3 5.3 3.8 5.0 4.4 4.0 4.5 4.0 4.8 5.3 4.7 3.4 64.5 90.3 78.5 78.7 82.5 94.9 74.8 84.9 82.9 86.1 71.9 82.6 80.9 68.3 79.9 77.1 64.3 58.8 56.4 59.8 51.3 54.5 52.9 58.3 52.7 58.4 54.5 56.0 51.7 50.5 1974------------------12.9 Average-------------11.0 Cape Fear 1971-----------------10.6 1972 .-----------------12.0 1973 .------------------- 9.8 1974---- -- ---12.0 Average-------------. 11.1 Farley 1971-------------------11.1 1972 ------------------- - 11.2 _ .708 .793 .754 .772 .756 .866 .628 .758 .795 .729 .760 .799 .753 1973.--------- --------- 10.0 1974.---Average- ------------10.2 ------------10.6 ----------------- 10.7 54.6 55.3 57.7 57.1 53.0 80.0 76.3 96.4 61.2 82.1 61-4-35 1974 45-3-3 1974 ------------ 10.6 Cheyenne 1972------------------- 1974 ----------------------Average-----------------Wichita 1974 1973-------------------------- 10.5 9.3 9.4 9.7 9.1 10.4 9.9 62.2 58.6 58.5 59.8 55.6 62.5 61.9 60.0 51.9 56.5 61.3 55.7 57.8 75.7 81.1 85.6 1972-------------------------Average------------- 1973---------------------------10.2 --------------------------. 84.3 82.0 92.9 86.4 69.8 87.7 87.1 81.7 855 .830 .794 .717 .817 .795 .781 .797 7.9 6.5 7.2 6.0 Cherokee 1974-----------------------Caddo 1972.-------------------- 9.0 8.9 7.5 1973-------------------------1974-----------------------Average --------------------------- 1------------------- , 9.7 8.7 -Y1 4.1 3.7 7.6 4.2 6.9 - 4.0 Continued [81] TABLE 2 (Con't.). YEARLm AVERAGE MEASUREMENTS OF SELECTED NUTS AND KERNEL CHARACTERISTICS OF PECAN VARIETIES UNDER EVALUATION AT THE GULF COAST SUBSTATION, FAIRHOPE Variety and year Volume Amount of kernel Calculated fill' density2 weight weight cc Pct. Pct. Grams Grams Elliott 1971 --------------------------------8.2 53.7 83A 0.801 6.6 3.5 1972.-------------------------------- 8.0 53.1 90.4 .846 6.8 3.6 1973 ----------------------------------7.1 53.7 78.9 .771 5.5 3.0 1974------------------------------ 8.4 52.5 82.2 .797 6.7 3.5 Average.----------------------------. 7.9 53.3 83.7 .803 6.4 3.4 Starking 1973----------------------------------7.8 59.5 86.6 .798 6.2 3.7 48-15-3 1972------------------- 7.2 46.8 80.3 .774 6.6 3.1 1973 ---------------------------------7.2 57.7 84.8 .793 5.7 3.3 1974 ---55.6 5.8 3.2 Average..--------------------------7.2 53.4 82.6 .783 6.0 3.2 Chickasaw 1972___________----------_______---- 7.0 58.6 72.6 .706 5.0 2.9 1974 ------------ 9.3 52.6 59.4 .636 5.9 3.1 Average 8.2 55.6 66.0 .671 5.5 3.0 53-11-139 1974--------------------------------- 6.9 53.7 77.8 .764 5.3 2.8 ---------------------- 'Calculated percent fill is the percent of the interior space of a nut that was filled by the kernel. - Density Was obtained by dividing nut weight by nut volume as measured by Volume of water displaced at total immersion. ' Data taken from nut sample of limited size. Mohawk, Kernodle, and Mahan-Stuart were the only varieties with heavier nut weight than Stuart and Desirable, the largest of recommended varieties. This indicates excellent NUT WEIGHT. inshell usage potential for them. Starking, 48-15-3, Chickasaw, and 53-11-139 had lower individual nut weights than Elliott, the smallest recommended variety. KERNEL WEIGHT. Mohawk and Mahan-Stuart kernel weights exceeded that of Desirable, indicating the potential of these varieties for producing giant mammoth halves for the shelling trade. Kernodle, although large, lacked data. for such use, as indicated by calculated Low kernel weights exhibited by 45-3-3, Cherokee, and Chickasaw reflect both insufficient kernel development and small size, whereas kernel weights of Starking, 48-15-3, and 53-11-139, although smaller than Elliott, indicate that kernels were well developed. [9] fill sufficient development r tI, IL.E BARTON CADDO nil': DES IRABLE ELLIOTT FARLEY HASTINGS 4"I uIt KERNODLE I {4 MAHAN - STUART MOHAWK SHAWNEE '5t 1 5 SHOS HON I CAPE FEAR fp I~CHEYENNE CH ICKASAW iit WICHITA I,4 STUART 48-15-3 GRABOHLS I CHEROKEE 61-4-35 NUTS PER POUND. Mohawk was the largest nut evaluated, averaging 39 nuts per pound in contrast to averages of 76, 84, and 86, respectively, for 48-15-3, Chickasaw, and 53-11-139. Elliott, the smallest recommended variety, averaged 72 nuts per pound. Twenty of the 25 varieties and selections evaluated had nuts smaller than Stuart, on the basis of number of nuts per pound. Varieties considered for the inshell trade should have no more than 55 nuts to the pound. Since nuts are individually cracked at shelling plants, varieties grown primarily for this outlet can be smaller types; however, these should not exceed approximately 75 nuts per pound. Yearly differences in percentage of nuts in various diameter sizes occurred with all varieties and selections, Table 3. Year-to-year fluctuations in soil moisture availability during the rapid fruit growth period prior to shell hardening probably account for most of these differences. Over 50 percent of Mohawk, Mahan-Stuart, SAMPLE PERCENTAGE ACCORDING TO DIAMETER. TABLE 3. YEARLY AVERAGES OF NUT SIZE DATA OF PECAN VARIETIES UNDER EVALUATION AT THE GULF COAST SUBSTATION, FAIRHOPE Variety and year Nuts per pound Percent of sample according to diameter (inches) 17/16 16/16 15/16 14/16 13/16 12/16 11/16 Nut length No. Mohawk 1972 .......42 Pct. Pct. 20.0 Pct. 70.0 Pct. 10.0 Pet. Pct. Pct. mm 48 1973........ 1974 .... Average .... 1971-......... 1972 ..-- 38 37 89 44 40 47.5 87.5 41.4 12.5 8.1 2.0 1.0 52 51 50 47 47 Mahan-Stuart 66.6 95.0 31.1 5.0 2.2 15.0 8.3 0.4 1973----1974 ......Average... 46 45 44 2.0 50.0 30.6 35.0 58.7 46 47 47 Xernodle 41 1971....... 39 1972 ..--... 52 1973 ........ 44 Average.-56.9 20.0 15.0 42.3 75.0 82.5 0.6 5.0 2.5 49 49 47 49 44 45 43 Desirable --.... 44 1971 .... 40 1972 . 53 1973 ...... 92.3 82.5 20.0 6.8 15.0 55.0 3.4 2.5 22.5 2.5 1974 ...... Average-- 43 45 1.5 23.4 67.9 7.2 46 45 Continued [12] TABLE 3 (Con't.). YEARLY AVERAGES OF NUT SIZE DATA OF PECAN VARIETIES UNDER EVALUATION AT THE GULF COAST SUBSTATION, FAIRHOPE Nuts Percent of sample according to diameter (inches) Variety Nut yard pun No. 17/16 16/16 15/16 14/16 13/16 12/16 11/16 Pct. Pct. 94.6 20.0 45.0 54.4 Pct. 66.6 52.5 43.1 Pct. 13.3 2.5 Pct. Pct. Pct. length mm 44 42 42 44 43 Stuart 1972 --- 48 1973------52 43 1974.Average- 1971 ------ 43 5.3 2.5 47 2.3 43.2 61-4-35 1974 ------49 61-6-96 1973 --- -53 Hastings 197153 ----.49 52.3 30.0 2.3 60.0 44 51 45 45 45 46 45 33 40 37 10.0 97.3 86.6 63.3 45.3 100.0 28.9 2.6 13.3 20.0 1972--- 1974.-----Average-. 1973.- 56 53 34.7 10.0 53 Shoshoni 1973'_----57 1974------48 Average---53 Shawnee 19721- 66.7 4.4 100.0 5.0 4.7 45.9 40.0 50.0 50 57 1973 ---1974.--52 53 Average 45-10-23 1971------50 0.3 25.0 34.0 13.5 70.0 61.0 40.5 60.0 20.0 51 48 51 50 58 59 55 57 41 43 41 1972-------1973.-- 48 65 30.0 Average--__54 Cape Fear 1971------- 55 1972----47 1973.------ 66 1974.---- 48 3.0 48.7 30.0 2.5 24.0 27.2 20.0 2.5 0.9 48.1 60.0 47.5 56.5 3.1 10.0 45.0 14.0 19.5 7.5 32.5 51.5 22.4 15.0 70.0 2.5 3.5 1.8 0.4 0.4 Average.-_.54 Farley 1971.---58 44 42 39 39 38 38 39 1972-------1973 -----1974 ------- 51 60 58 49.7 72.5 57.5 43.3 69.8 45.0 15.0 II 7.5 3.9 0.4 Average 57 Rarton 1971 ----- 58 1972----- 43 1973----71 Average 57 7.7 40.0 15.0 46 48 47 47 Continued r 131 TABLE 3 (Con't.). YEARLY AVERAGES OF NUT SIZE DATA OF PECAN VARIETIES UNDER EVALUATION AT THE GULF COAST SUBSTATION, FAIRHOPE Variety Nuts and year per pound 17/16 16/16 No. Pct. Pc. Percent of sample according to diameter (inches) Nut 15/16 14/16 13/16 12/16 11/16 length Pct. Pct. Pct. Pet. Pct. mm 16.6 57.1 33.3 22.4 33.3 16.6 46 48 GraBohls 1973'--------61 1974.--52 Average.---- 57 Wichita 1972--63 1973.--------- 59 1974---------53 Average----- 58 Cheyenne 19721974----------Average.---57 61 66 61 20.4 47 10.0 50.0 34.1 80.0 50.0 57.2 10.0 7.9 0.3 47 50 49 0.6 49 10.0 30.0 33.3 80.0 60.0 56.0 10.0 10.0 1973- 40 40 0.2 0.2 8.5 1.8 41 40 46 Caddo 1972 ---------- 63 1973-___ 50.0 5.0 66.7 50.0 90.0 25.0 1974 ---------60 Average----_ 66 68 45-3-3 1974.--------. Cherokee 1974 76 10.0 3.3 45 48 46 1.7 61.7 100.0 35.8 0.8 45 38 -------. 70 81.1 53.3 36.6 75.8 Elliott 69 10.8 1971----------1972 ---------67 1973---------- 82 Average_Starking 1974----68 1973-------- 7.4 46.6 50.0 18.6 0.4 36 36 13.3 1.6 0.4 34 35 35 3.6 72 73 30.0 60.0 10.0 39 48-15-3 1972.----_ 1974.---79 Average.-. 76 Chickasaw 19721__-_. 91 77 5.5 1973----79 69 5.0 10.0 70.0 85.0 25.0 5.0 2.7 34 35 58.1 39.2 34 34 36 39 1974-------Average--. 53-11-139 1974 1Data 100.0 80.8 13.7 84 86 10.4 38 58.9 29.9 0.8 36 ----F14]1 taken from nut sample of limited size. Desirable, Stuart, Hastings, and Shoshoni nuts were 16/16 inch in diameter or larger. In contrast, over 50 percent of Shawnee, Wichita, Caddo, Starking, Chickasaw, and 53-11-139 nuts were 13/16 inch in diameter or smaller. NUT LENGTH. Varieties and selections that had distinctly long and narrow nuts were 61-4-35, 61-6-96, 45-10-23, Shawnee, Barton, and Wichita, Table 3. Those with more rounded nuts were Chickasaw, 48-15-3, Elliott, Cheyenne, and Shoshoni. Kernels in exceptionally long nuts frequently fail to develop the entire length. This was particularly characteristic of the selection 45-10-23. KERNEL COLOR. Elliott, Cape Fear, Kernodle, Shawnee, Cheyenne, and CraBohls stood out as having bright meats, Table 4. Cherokee and Wichita were substantially darker than Stuart, even though this is not apparent in the color plates. Bright colored kernels command higher prices than standard and amber ones. The illustrations (pages 10-11) reflect characteristic nut and TABLE 4. OBSERVATIONAL RATINGS OF KERNEL COLoR OF VARIETIES AND SELECTIONS EVALUATED Variety B a rton _- - - -- - - -- - - - -- - - -- - - - -- - - -- - - -- - - - -- - - -- - - - -- - - -- - ---- Kernel color1 3 48-15-3 -- - - - - - - - - - - - - - - - - - - - -- - - - - - - - - -3 Cad do - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -3 Elliott-------------------------------------------------------- -------------Farley-3 Cape Fear--------------------------------------------------------------------4 Kernodle--------------------------------------------------- 4 4 Mohawk .-------------- -------- Y---------------------------------------Shawnee------------------------------------------------------------ 3 4 3 Shoshoni------------------- --- Cheyenne-----------------------------------------------------------Ch ickasaw .------------- ------ ----- -- ------- --------Stuart.---------------------------------------------------------45 -10 -23 -- - - - - - - - W ich ita ------------------ -------------------- 4 3 Desirable------------------------------------------------------------ 3 3 Ch e rok e e -- - - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - -1 G raBohis--------------------------------------- -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .3 -------.----- ------ ------------------------2 ---------4 Hastings -------------- _------------------------------------------------------Mahan-Stuart-----------------------------------------------------------3 S rkin g . --------------------ta -------------------- ----- 3 3 61-6-96---------------------------------------------- 61-4-35----------------------------------------------------------------------53-11-139 -- -- --- ------ -------- --.---- ------. 45 -3-3 --- - - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - - - -3 Kernel color rating: --------- -- 3 3 I = dark; 5 = very bright. [15] kernel shapes, shell markings, and kernel surface texture patterns. Comparable size differences between varieties and selections are also shown. The nuts and kernels are shown at approximately 65 percent of natural size. Lighter colored shells of varieties and selections such as GraBohls and Mohawk are more attractive than darker shells. A kernel defect caused by the packing tissue adhering to seed coat of the kernel, referred to as fuzziness or adherence, is readily observable with Hastings and Barton. Color rendition in these plates reflects actual appearance, except that Cherokee appears lighter than natural. DISCUSSION Early maturing varieties allow for movement of nuts into marketing channels generated by the Thanksgiving and Christmas holidays the same year they are harvested. Another advantage of early ripening is that machine harvesting is more efficient and greatly facilitated if carried out prior to appreciable leaf fall. However, varieties that ripen mid-October and earlier present a particular problem in the trunk shaking portion of the harvest operation. Cambium activity is still in progress at this time and bark slippage readily occurs during shaking. This bark slippage injury may result in partial to nearly complete girdling of the tree. Consequently, these early and mid-season ripening varieties may require limb shaking instead of trunk shaking to circumvent this problem. The varieties Farley and Hastings were considered excessively late in maturing nuts. Varieties and selections having nut diameters below 15/16 inch were prone to bird depredation, particularly if they were extremely early or late maturing varieties. Much of this depredation occurred prior to the time when nuts could be shaken down. Most varieties and selections evaluated were smaller inshell (as indicated by nut volume, diameter, nuts per pound, and nut weight) than Stuart, which is considered a large size nut. Despite their smaller inshell size, however, kernel weight of Cape Fear, Shawnee, Shoshoni, GraBohls, 61-6-96, 61-4-35, Wichita, and Cheyenne did not appreciably differ on a per kernel weight basis from that of Stuart. This may be attributed to the greater percent kernel in nuts of these varieties and selections. Year-to-year kernel weight differences with a variety or selec[16] tion can have considerable economic impact. For example, differences as great as 1.1 grams per kernel occurred for Cape Fear between years 1972 and 1973. Such differences could amount to a per acre kernel yield difference of about 200 pounds, as shown by the following computation: A Cape Fear tree that yields 40 pounds of nuts with a 47 nuts to the pound count has matured approximately 1,880 nuts. If the resulting kernels extracted from these nuts averaged 5.1 grams, the yield of that tree would amount to about 21.1 pounds of kernel. If the same tree were subjected to untimely drought stresses, these 1,880 nuts could have a 66 nuts to the pound count, or a 4.0-gram average kernel weight. This would result in only 16.3 pounds of kernel being produced by the same tree, a difference of 4.8 pounds per tree. When applied to a high density planting of trees spaced 35 x 30 feet (41.5 trees to the acre), this difference would amount to 199.2 pounds of kernel per acre. Uncontrolled drought stresses, whether due to insufficient rainfall and/or excessive orchard floor vegetation, can therefore readily reduce the marketable yield of any variety. Of the varieties and selections evaluated for 2 years or longer, Shawnee, Shoshoni, Cape Fear, Cheyenne, Wichita, Caddo, Elliott, and 48-15-3 had the greatest capacity to fill nuts consistently year after year. The ability of Mohawk, Mahan-Stuart, Desirable, Stuart, and Farley to fill nuts was only slightly less. In comparison, Kernodle, Hastings, 45-10-23, Barton, and Chickasaw appear to be lacking in this ability to consistently fill nuts, particularly in large crop years. Even though these latter varieties, with the exception of Hastings, had kernel percentages in excess of 50 percent, the kernel could be characterized as being thin rather than the desired plump state. Stuart's ability to consistently fill in high crop years and its large size probably explain the variety's long standing popularity. Ripening date and nut and kernel characteristics are only a part of the overall considerations that must be evaluated in identifying successful commercial varieties. Such aspects as the degree of prolificness, productivity, scab resistance, and adaptability to high density plantings also must be considered and may override the less objectionable nut and kernel qualities. [17] APPENDIX Origin and Observations of Varieties and Selections Barton. Originated in Brownwood, Texas, by L. D. Romberg, USDA Pecan Field Station. Moore x Success cross made in 1937, tested as USDA T-15, introduced in 1953. Heavy crop set on trees severely reduces kernel yield and quality. Caddo. Originated in Philema, Georgia, by late C. A. Reed, USDA. Brooks X Alley cross made in 1922 or 1923; tested as Philema 1175. Difficulty encountered in shelling in respect to damaging kernel shoulders. Desirable. Originated in Ocean Springs, Mississippi. Chance seedling of Success selected about 1903; introduced in 1930. Shellers use this variety to obtain mammoth halves. Elliott. Originated in Santa Rosa County, Florida. Parentage unknown, discovered about 1915, introduced about 1925. A round nut that consistently is well filled. Shells readily into intact halves. Farley. Originated in Jackson County, Florida, parentage unknown. Discovered about 1918, introduced about 1925. Difficult to harvest at Gulf Coast Substation before extensive bird predation. A squarish shaped nut considered too late in maturity for commercial plantings. Hastings. Originated in Monticello, Florida. Open-pollinated seedling of Stuart selected about 1945, introduced as a patented variety in 1955. Large oval nuts with thin shell. Packing tissue within shell adheres to kernel, kernels tend to be hollow. Hastings has consistently been the poorest quality variety evaluated. Kernodle. Originated in Camp Hill, Alabama, by late Julius A. Kernodle. Chance seedling discovered in 1948, introduced in 1957, patented in 1958. A large flat nut; lacks ability to fill in heavy crop years. Kernels have attractive appearance and can be cracked into halves readily, but show some tendency to exhibit dark markings on kernel surface. Mahan-Stuart. Originated in Monticello, Florida. Mahan X Stuart seedling selected in 1948, introduced in 1956 as a patented variety. A large elongated oval nut with good kernel quality. Mohawk. Originated in Brownwood, Texas, by L. D. Romberg, USDA Pecan Field Station. Success X Mahan cross made in 1946, selected in 1954, tested as 46-15-195. Introduced in 1965. A large nut having good inshell and potential shelling possibilities for the commercial grower. Shawnee. Originated in Brownwood, Texas, by L. D. Romberg, USDA Pecan Field Station. Schley X Barton cross made in 1949, tested as 49-17166, introduced in 1968. Excellent quality nut. Shoshoni. Originated in Brownwood, Texas, by L. D. Romberg, USDA Pecan Field Station. Odom X Evers cross made in 1944, tested as 44-15-59, released in 1972 by G. Madden. A large, early maturing nut possessing resilient shell making cracking somewhat difficult. Shells out intact halves readily. A good possibility for the early inshell as well as shelling trade. Cape Fear. Originated at the Coastal Plain Branch Station of the North Carolina Experiment Station, Willard, North Carolina. Open-pollinated seedling of Schley planted in 1912, introduced in 1941. Inshell nut re[18]1 sembles Stuart but has brighter kernels and higher percent kernel. Just slightly smaller inshell than Stuart. Cheyenne. Originated in Brownwood, Texas, by L. D. Romberg, USDA Pecan Field Station. Clark X Odom cross made in 1942, tested as 42-13-2, introduced by G. Madden in 1970. Has bright kernels, high percent kernel. Has ability to fill in years of high crop load. This variety considered most adaptable for high density plantings in Alabama. Chickasaw: Originated in Brownwood, Texas, by L. D. Romberg, USDA Pecan Field Station. Brooks X Evers cross made in 1944. Tested as 44-4101, released in 1972 by G. Madden. A small nut that may not fill satisfactorily in years of high crop loads. Wichita. Originated in Brownwood, Texas, by L. D. Romberg, USDA Pecan Field Station. Halberg X Mahan cross made in 1940. Tested as 40-9-193 and released in 1959. Has ability to fill nuts in years of heavy crop loads. Kernel color deteriorates rapidly. Stuart. Chance seedling transplanted from Mobile, Alabama, to Pascagoula, Mississippi, in 1874. Nursery trees offered for sale about 1892 by a Colonel Stuart. Lowest percent kernel of varieties evaluated. 45-10-23. Originated in Brownwood, Texas, by L. D. Romberg, USDA Pecan Field Station. Moore X Mahan cross made in 1945. An elongated nut that does not fill sufficiently. Not illustrated. Starking. Originated in Brunswick, Missouri, by G. James. Chance seedling, parentage unknown, discovered in 1947, introduced in 1954, patented in 1955. A small nut having no apparent commercial attributes. 48-15-3. Originated in Brownwood, Texas, by L. D. Romberg, USDA Pecan Field Station. Major X Evers cross made in 1948. The earliest maturing selection evaluated. A small nut that readily cracks into intact halves. 61-6-96. Originated in Brownwood, Texas, by L. D. Romberg, USDA Pecan Field Station. Mohawk X Starking cross made in 1961. A large, attractive, inshell nut. Not illustrated. GraBohls. Originated near Austin, Texas, by the late H. C. Bohls. Possibly a Mahan X Odom cross made in the 1940's. Originally named Mary. Introduced in 1973, patented in 1974. This variety has not exhibited the ability to fill its nuts even under light fruit set. Cherokee. Originated in Brownwood, Texas, by L. D. Romberg, USDA Pecan Field Station. Schley X Evers cross made in 1948; tested as 48-22-27 and released in 1971 by G. Madden. Kernel color is normally darker than desired. 53-11-189. Originated in Brownwood, Texas, by L. D. Romberg, USDA Pecan Field Station. Moore X Stuart cross made in 1953. Smallest selection evaluated. Not illustrated. 45-3-3. Originated in Brownwood, Texas, by L. D. Romberg, USDA Pecan Field Station. Brake X Georgia No. 1004 cross made in 1945. Selection did not exhibit ability to fill in this evaluation. Not illustrated. 61-4-35. Originated in Brownwood, Texas, by L. D. Romberg, USDA Pecan Field Station. Schley x Starking cross made in 1961. Medium size, well filled. E19 1 Alabama's Agricultural Experiment Station System AUBURN UNIVERSITY U With an agricultural research unit in every major soil area, Auburn University serves the needs of field crop, livestock, forestry, and horticultural producers in Q Q e 7 12 each region in Alabama. Every citizen of the State has a stake in this research program, since any advantage from new and more economical ways of producing and handling farm products directly benefits the consuming public. O 0 Q Ye n Research Unit Identification 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. Tennessee Volley Substation, Belle Mina. Sand Mountain Substation, Crossville. North Alabama Horticulture Substation, Cullman. Upper Coastal Plain Substation, Winfield. Forestry Unit, Fayette County. Thorsby Foundation Seed Stocks Farm, Thorsby. Chilton Area Horticulture Substation, Clanton. Forestry Unit, Coosa County. Piedmont Substation, Camp Hill. Plant Breeding Unit, Tallassee. Forestry Unit, Autauga County. Prattville Experiment Field, Prattville. Black Belt Substation, Marion Junction. Tuskegee Experiment Field, Tuskegee. Lower Coastal Plain Substation, Camden. Forestry Unit, Barbour County. Monroeville Experiment Field, Monroeville. Wiregrass Substation, Headland. Brewton Experiment Field, Brewton. Ornamental Horticulture Field Station, Spring Hill. Gulf Coast Substation, Fairhope.