Gibberellic Acid 4þ7 In£uences Shoot Growth of Seedling Pecan and Bitternut Hickory1

Brandon M. Miller, Nina L. Bassuk

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


Shoot development of seedling hickories is slow, limiting their success as viable crops using standard growing techniques. Because hickories are predominantly propagated by seed, we questioned whether gibberellic acid (GA) could be used on seedlings to overcome slow shoot development during juvenility. Treatments of one-year-old seedlings of bitternut hickory [Carya cordiformis (Wangenh.) K. Koch], pignut hickory [C. glabra (Mill.) Sweet], pecan [C. illinoinensis (Wangenh.) K. Koch], kingnut hickory [C. laciniosa (F. Michx.) Loud.], shagbark hickory [C. ovata (Mill.) K. Koch], and mockernut hickory [C. tomentosa (Lam.) Nutt.] began at bud break by applying a solution of 500 ppm GA4þ7 dissolved in 95% ethanol directly to apical buds or stem tissue at three-day intervals for 27 days. After 160 days, neither treatment affected caliper of any taxon, although species differences were observed. Compared to nontreated control plants, treatment of buds resulted in a 234% and 144% increase in shoot height of bitternut hickory and pecan, respectively. In a second experiment, the same treatments were implemented on seedlings of bitternut hickory shortly after germination. Only shoot height and dry weight were affected (increased) by application of GA4þ7. This study indicates plant growth regulators could be effective at increasing shoot extension of some hickories.

Original languageEnglish (US)
Pages (from-to)39-45
Number of pages7
JournalJournal of Environmental Horticulture
Issue number2
StatePublished - Jun 2022

Bibliographical note

Funding Information:
Received for publication Dec 27, 2021; in revised form April 30, 2022. 1This work was supported in part by the Horticultural Research Institute and USDA National Institute of Food and Agriculture, McIntire-Stennis, Smith-Lever project 1020775. We thank Alana McKean and Guy Sternberg of the Starhill Forest Arboretum and Dr. Douglas Goldman of the USDA-NRCS for collecting and donating seeds of pecan and mockernut hickory. From a dissertation submitted by Brandon M. Miller in partial fulfillment of the requirements for the degree of Doctor of Philosophy. 2Assistant Professor. Department of Horticultural Science, University of Minnesota, 254 Alderman Hall, 1970 Folwell Avenue, Saint Paul, MN 55108.

Publisher Copyright:
© 2022, Horticultural Research Institute. All rights reserved.


  • Carya
  • Species diversity
  • nursery production
  • plant growth regulators


Dive into the research topics of 'Gibberellic Acid 4þ7 In£uences Shoot Growth of Seedling Pecan and Bitternut Hickory1'. Together they form a unique fingerprint.

Cite this