Impact of vegetation control and annual fertilization on properties of loblolly pine wood at age 12

The wood products industry is using herbicides to control competing vegetation, as well as fertilizers to increase growth in southern pine. In 1987, a longterm monitoring study was established to determine the growth potential of loblolly pine (Pinus taeda L.) in the southeastern United States (Borders and Bailey 2001). Very intensive cultural practices were applied including intensive mechanical site preparation, completevegetationcontrolwithmultipleapplications of herbicides, annual high rates of nitrogen fertilization, and complete vegetation control plus annual fertilization. Borders and Bailey (2001) report that growth increased up to 270 percent in response to the intensive cultural treatments. Volume mean annual increment at age 12 for the trees receiving complete vegetation control plus annual fertilization was 325 to 490 ft. of wood per acre per year, growth rates which are comparable to the best loblolly pine growth anywhere. It was concluded that growth rates in loblolly pine plantations under conventional management in the southeastern United States (100 to