Genotype and Herbicide Affect Hybrid Sweetgum Growth and Development on two Upland site in North Louisiana
Date of Award
Master of Science (MS)
American Sweetgum (Liquidambar styraciflua) was hybridized by ArborGen and the University of Georgia with Formosan Gum (Liquidambar formosana) to create a faster growing hardwood variety that can produce greater volumes of pulpwood on shorter rotations. In this study growth rate and physiological factors of five clonal hybrid varieties were tested against a native half-sib family to determine if the hybrid gum varieties were superior. All hybrid varieties grew significantly taller and larger at ground line than the native family. Indeed, the largest hybrid variety in both height and ground line diameter was 94.7 cm taller and 13.9 mm wider than the native family after two growing seasons. Another test was conducted within this study to determine how herbicide application timing affected the growth and survival of the hybrid gum varieties, as they break dormancy earlier than native sweetgum, and it has been documented that mortality can occur when herbicide is applied over actively growing sweetgum. Each of these tests were carried out at two locations, Louisiana Tech in Ruston, Louisiana, and LSU AgCenter’s Hill Farm Research Station in Homer, Louisiana. Over 99% of the sample trees at Louisiana Tech survived for the duration of the study across all herbicide treatments. At Hill Farm over 90% of the sample trees survived the two year duration of the study.
Hane, Robert, "" (2022). Thesis. 83.