Alphabetic Search by Cultivar Name
L. J. Grauke and T. E. Thompson
Following is a revision of the information on pecan cultivars for the Cultivar Register. Cultivars were added: 1) if they have ever been patented; 2) if there is considerable acreage (based on Thompson, T. E. Pecan South 24:12-17, 20. 1990); 3) if they were the result of controlled cross; 4) if they were used as parents in controlled crosses of major cultivars; or 5) if they are included in the recently formed Core subset (Grauke, L. J., Thompson, T. E. and Marquard, R. D. HortScience 30:950-954. 1995). Cultivars on previous lists were deleted if they are obsolete and obscure. Any cultivar recommended for planting in any state in Thompson, 1990, is retained. Any cultivar on the list having unusual origin, history, or characteristics is retained.
For each entry, history of origin is presented chronologically, with brief but important details included. The exhaustive bibliography provided by Thompson and Young (Pecan Cultivars-Past and Present, Texas Pecan Growers Assn., publ., College Station, TX. 1985. ) was invaluable in that effort, as was the library of books, periodicals and notes that we maintain on cultivars at the Breeding Program. Darrell Spark's book (Pecan Cultivars: The Orchard's Foundation, Pecan Production Innovations, Watkinsville, GA. 1992. ) provides excellent synopses for many cultivars, with a thorough citation of relevant literature, and was also very helpful.
Uniform descriptors are needed for distinctive parameters of shuck, nut, kernel, bark, tree form, phenology, production parameters and insect and disease reaction. The primary effort in this revision has been to use consistent descriptors of nut shape. Nuts are described as viewed from the side, with suture showing. Descriptors of shape are based on nut length to height ratios, where height is measured as the widest point perpendicular to the plane of the suture. The classes are outlined in the table below:
Descriptors for pecan nut shape based on nut length to height ratios.
Descriptors of apex and base shape are very rudimentary;
. Cross section form is described as
Determination of these values is based on evaluation of the samples maintained in our nut voucher collections, when possible, or on evaluation of photographs if no nuts or reliable data was available.
Values are given for number of nuts per pound and percent kernel, the standard characteristics used to describe pecans by the industry. Values provided by George McEachern from the Texas Pecan Show Handbook are used for most western and many southeastern cultivars. Values for northern cultivars were provided from Kansas Pecan Show averages and Northern Nut Grower averages, provided by Bill Reid. These represent averages of the very best performance of the cultivars. For some entries, the numbers describe less prestigious samples.
Dichogamy class is described as protandrous or protogynous based on our observation or reliable reports, with pollen shed and pistillate receptivity further described as "early", "mid-season" or "late". Patterns of bloom for a cultivar will vary slightly from season to season, relative to other cultivars, making detailed description of bloom patterns of questionable value. This system allows estimation of bloom overlap between cultivars at a glance, and is more reliable than merely "protandrous" or "protogynous".
Description of disease resistance is based on our observations, published literature, and on the notes of Glenn KenKnight and Richard Hunter (both retired USDA pathologists).
For some cultivars, photographs are provided. Nuts were photographed under standard conditions.
Alphabetic Search by Cultivar Name
Warren Chatwin , Research Geneticist
USDA-ARS Pecan Genetics
Route 2 Box 133
Somerville, TX 77879
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