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Dennis Ring

Dr. L.J. Grauke shares his memories of Dr. Dennis Ring and his years of work and service to pecans.


Dennis Ring's 1987 annotated voucher of C. palmeri from the USDA-ARS.

I met Dennis Ring in the late 1970s when we were both graduate students at Texas A&M University. Dennis was working on casebearer (Acrobasis nuxvorella) and had seen evidence of infestation in nuts on trees of the Eli Whiteley memorial planting at Texas A&M University. I knew that planting was a hybrid swarm that included water hickory (Carya aquatica), pecan, and their interspecific hybrid (Carya X lecontei). Dennis was curious about distinguishing the hybrids from the two parents. I could do that because I had studied herbarium vouchers of hickories confirmed by experts like Dr. Donald E. Stone (Botanist, Duke University). Casebearer was not known to infest water hickory, and Dennis thought he had seen nut infestations on C. aquatica. If infestations were on the hybrid, interpretations changed. Dennis was already famous in my mind because of the work he and Marvin Harris had done on pecan weevil and the casebearer emergence model. I was happy to be included in this conversation with a serious student of the genus.

I got my Ph.D. in Horticulture under Dr. J. Benton Storey in 1982 and immediately went to the LSU Pecan Station south of Shreveport to work as a horticulturist. I continued to work with hickories for a rootstock project I began at the LSU Pecan Station. Dennis visited me there in 1985. He, Sherry, and young Megan stayed with Wren and me and our son Gabriel at our farm in Frierson, while Dennis and I explored hickory populations all over that area. We made herbarium voucher specimens of our collections, which Dennis sent to Donald Stone for confirmation of their identification. Dennis later made collections from hickories across the United States, documented with herbarium voucher specimens annotated by Donald Stone and myself. Dennis sent me the herbarium vouchers, and they are maintained in herbarium cabinets at the College Station worksite of the USDA Pecan Breeding & Genetics Program. Those vouchers represent the mother trees for living inventories grown from their nuts at the USDA Southeastern Fruit and Tree Nut Lab in Byron, Georgia. Bruce Wood (Horticulturist, SEFTNL, Byron, Georgia) continued to study those trees, and we published a paper based on those studies in 2011. Even though Dennis is not an author on the paper, his meticulously documented vouchers are a beautiful foundation of that work and for future work in the genus.

I worked with Jerry Payne (Entomologist, SEFTNL, Byron, GA) and Bruce Wood to make collections from native pecan populations across the United States in 1986 and from native pecan, hickory, and walnut populations across Mexico in 1987. We made collections from Carya palmeri, a rare hickory that only occurs in Mexico, at Cola de Caballo near Monterrey in early September. None of the nuts we collected germinated. We found what looked like weevil exit holes in some of the nuts. Dennis returned to those populations for additional collections that same month as he worked on his study of weevil infestations in Carya. He gave me two nuts, one of which germinated. To my knowledge, that tree is the only living inventory of Carya palmeri north of Mexico. I have always called it the “Ring Palmeri.” It is now a mature, nut-bearing tree and has been represented in several molecular characterizations of genetic diversity in the genus Carya.

The last time I saw Dennis was at the TriState ArkLaMiss Pecanference in 2019. He told me about the health challenges he faced. I asked him why he had not retired but was still working since time might be short and that knowledge makes it sweet. He said he loved what he was doing and believed it was valuable. I was reminded of Psalm 90 in which Moses prays to God, remembering his own temporariness and God’s permanence. The prayer ends “Establish the work of our hands for us. Yes, establish the work of our hands.” I believe God has answered that prayer for Dennis Ring.

Author Photo

L.J. Grauke

Dr. LJ Grauke is a retired Research Horticulturist with the Pecan Genetics and Breeding Program in the USDA Agricultural Research Service. After 30 years of service, Dr. Grauke moved onto a new adventure. The Pecan South staff and family thank Dr. Grauke for his years of service and wish him all the best. If you have questions or comments regarding this article, please contact Joshua Udall or Xinwang Wang with USDA-ARS via [email protected] or [email protected] respectively.