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Germination of Northern Red Oak: Effects of Provenance, Chilling, and Gibberellic Acid

Early studies of northern red oak (Quercus rubra L.) seed dormancy pointed to existence of embryo dormancy (Korstain, 1927; Cox, 1942; McDermott, 1941), and recent observations of gibberellic acid effects (Vogt, 1970) support this hypothesis. Jones and Brown (1966), on the other hand, noted that excised embryos and seed with the apical end of the pericarp removed or split exhibited no dormancy. They concluded that pericarp structure causes dormancy, and cell expansion during stratification exerts enough pressure to burst the pericarp. While cold stratification for various periods has been recommended for breaking dormancy, observations in some southern red oaks (Q. nigra L., Q. phellos L., Q. shumardzi Buckl., Q. falcata var. pagodaefolia Ell.) indicate that these species do not have absolute stratification requirements (Usanis, 1968; Bonner, 1970). Russell (1971) has noted that successful storage conditions for red oaks (i.e., low temperature, high moisture content) are equivalent to stratification and will overcome dormancy. Suszka has recently suggested that a period of cold storage at collection moisture content may be sufficient to break northern red oak dormancy and that stratification may be unnecessary. In this study, Suszka's hypothesis has been tested. The chilling requirements of seed from several provenances, as well as their response to gibberellic acid (GA3), have also been determined.

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Author(s): Robert E. Farmer, Jr.

Publication: Tree Improvement and Genetics - Central States Forest Tree Improvement Conference - 1972