Date of Graduation
Davis College of Agriculture, Natural Resources and Design
Wood Science and Technology
Ray Hicks, Jr.
Poor regeneration of northern red oak is widespread in the central hardwood region. A two-part study was conducted to determine what fungi are associated with and cause cotyledon discoloration of northern red oak acorns. The field study determined that simulated small mammal notching, surface sowing, time, and site all play a significant role in the amount of cotyledon discoloration in acorns as well as the number of acorns with discoloration. However, germination rate was only affected by site and surface sowing, while seedling vigor ratings were actually higher when acorns had discolored cotyledons. The five species of fungi isolated most frequently were Penicillium chermesinum, Penicillium terrestre, Rhizopus sp., Trichoderma sp. and Fusarium sp. These fungi were used to inoculate northern red oak acorns during two inoculation trials. Cotyledon discoloration occurred in all acorns, but highest levels were evident with the Penicillium terrestre inoculations. Germination rates were lowest in the second inoculation probably as a result of better sterilization techniques used. Therefore, fungi apparently do not have a significant negative impact on northern red oak regeneration unless they enter before germination.
Washington, Dawn M., "Fungi associated with northern red oak (Quercus rubra ) acorns" (2003). Graduate Theses, Dissertations, and Problem Reports. 1405.