Early Pine Response to Control of Herbaceous and Shrub Vegetation in the Flatwoods

Abstract Herbicide treatments were used at four flatwood locations in north Florida and south Georgia to compare early pine response to control of herbaceous and shrub vegetation following bedding. Treatments consisted of three levels of shrub control (none, first year, repeated) with and without first year herbaceous vegetation control. All studies were located on spodosols planted with either loblolly (Pinus taeda L.) or slash (Pinus elliottii Englem.) pine. Responses due to shrub control were about twice that of herbaceous control with height responses of 2.2, 5.0, and 6.9 ft due to first year herbaceous control, shrub control, and the combination of both herbaceous and shrub control, respectively. Pine response did not differ due to duration of shrub control because the difference in shrub cover between first year and repeated shrub control treatments was minor in these young stands. Pines averaged 18.3 ft in height and 3.2 in. in dbh 5 yr after planting when both herbaceous and shrub vegetation was controlled with these operational-like site preparation treatments that combine bedding with first year herbicide applications. Shrub occupancy was highest on treatments that did not include shrub control and continued to increase through the first 5 yr. Operational site-preparation treatments that combine bedding with herbicide applications should be considered in situations where shrub vegetation is present because of the long-term impact that shrubs have on pine yield. South. J. Appl. For. 15(4):201-208.