Effect of directed-spray glyphosate applications on survival and growth of planted oaks after three growing seasonsThis article is part of a larger document. View the larger document here.
Thousands of acres of oak (Quercus spp.) plantations are established across the South annually. Survival and growth of these plantings have been less than desirable. Several techniques have been utilized in attempts to achieve improved success in these areas. One such technique that has been recommended is the application of directed-spray herbicide treatments. In this study, 3,240 bare-root Nuttall oak (Q. nuttallii Palmer) and white oak (Q. alba L.) seedlings were planted in February 2005 on Malmaison Wildlife Management Area near Carrollton, MS. One-third of the seedlings were subjected to a pre-emergent Oust® XP application in March 2005. One-third of the seedlings were treated with a pre-emergent Oust® XP application in March 2005 and directed-spray glyphosate applications throughout the 2005 growing season. One-third of the seedlings were subjected to pre-emergent Oust® XP applications in March of 2005, 2006, and 2007, and received directed-spray glyphosate applications once a month during the growing season each year. The effect of repeated directed-spray applications was evaluated, and significant differences were noted. Multiple examples of adverse seedling conditions were observed in the 3-year directed-spray plots. Seedling survival and total height were appreciably lower in 3-year directedspray areas compared to nondirected-spray or 1-year directed-spray areas.