Planted Pine Growth and Survival Responses to Herbaceous Vegetation Control, Treatment Duration, and Herbicide Application Technique

Abstract

Abstract Height, diameter, and survival of loblolly (Pinus taeda), longleaf (Pinus palustris), and slash (Pinus elliottii) pines in 16 plantations aged 2 through 7 yr were summarized for plots receiving herbaceous vegetation control treatments and for untreated check plots. Treatments tested at one or more sites included spot, banded, and broadcast herbicide applications for the first one or two growing seasons after planting. Analyses of variance and orthogonal contrasts were used to evaluate the effects of one or more of the following factors at each site: herbaceous vegetation control (treated vs. check); treatment duration (1 vs. 2 yr); and application method (band vs. broadcast or spot vs. band). Competition control had a significant positive effect on height and diameter at all 16 locations, and on survival or density where competition was most intense (5 of 14 sites). A second year of herbaceous vegetation control led to significant additional gains in height and diameter at 6 and 7 of the 10 locations, respectively, where those effects could be tested. Application technique had no significant influence on any pine attribute measured. South. J. Appl. For. 11(4):223-227.