The objectives for this research were to determine: 1) the rate of Micromax which will produce maximum growth of pin oak (Quercus palustris Munchh.), a landscape tree which has shown a previous growth response to the addition of Micromax at the manufacturer's recommended rate, 2) which micronutrient(s) is most associated with maximum growth, and 3) the rate of Cu, Fe, Mn, and Zn required to produce maximum growth of Quercus palustris. Q. palustris seedlings were container-grown in pine bark amended with the following rates of Micromax: 0, 0.15, 0.3, 0.6, 0.9, 1.8, or 2.7 kg(m-3 in 2000, 2001, and 2002. For all three years, the maximum growth was obtained at rates near the manufacturer's recommended rate of 0.9 kg(m-3. A micronutrient mix was formulated by increasing the levels of Zn, Mn, Fe, and Cu individually while holding the other micronutrients constant based on the grams of each micronutrient contained in Micromax at 0, 0.15, 0.3, 0.6, 0.9, 1.8, or 2.7 kg(m-3 for 2001 and 0, 0.45, 0.9, or 1.8 kg(m-3 for 2002. In addition, Cu, Fe, Mn, and Zn were also applied alone to pine bark at rates of 0, 0.45, 0.9, or 1.8 kg(m-3 without the addition of any other micronutrients. Holding all other micronutrients constant and increasing the rate of one micronutrient did not increase growth. However, when Cu, Fe, Mn, or Zn was added to pine bark alone at increasing rates, growth increased. For Cu and Zn, the growth increased was linear suggesting that a higher rate of Cu and Zn than that provided by Micromax at the manufacturer's recommended rate might be advantageous. / Master of Science

The objectives for this research were to determine: 1) whether sulfated micronutrient addition increased growth of container-grown pin oak (Quercus palustris MuÌ nchh) and Japanese maple (Acer palmatum Thunb.) seedlings by supplying micronutrients, sulfur, or decreasing substrate pH, 2) S requirements of Q. palustris and A. palmatum container-grown in a pine bark (PB) substrate, and 3) if there are any conditions that will affect these S requirements. Container grown Q. palustris and A. palmatum seedlings were grown in PB, amended (or not) with the following treatments: control (no amendment), Micromax (commercial micronutrient fertilizer [sulfate form]), K2SO4, H2SO4, HCl, chelated micronutrients, elemental S, or CaSO4. Dry weights of plants in all treatments supplying S were higher than for plants receiving no S. These data indicate that S, not micronutrient application, was the primary cause of increased growth from the addition of sulfated micronutrients. In other experiments these two species were fertilized with 8 different concentrations of S application (0, 1, 2, 5, 10, 20, 40, or 80 mg·liter-1). Regression analysis revealed dry weights of both species were near maximum at the extrapolated application concentration of 30 mg·liter-1 S, which corresponded to approximately 15 and 7 mg·liter-1 S in substrate solution for oak and maple, respectively. In another set of experiments plants were fertilized with Micromax or FeSO4 with or without lime. In the plus lime treatments (substrate pH 6.1), plant dry weights were higher in Micromax fertilized plants than for FeSO4 fertilized plants. However, in the minus lime treatment (substrate pH 4.5), FeSO4 addition effectively supplied S to plants. / Master of Science