. The Alexandria Research Center. Forests and forestry Research. 6 years after planting, these plots were prescribe-burned to control brown spot needle disease. Wild- fires burned over them at 8 years and 17 years after planting. Another controlled burn to remove excess fuel was made in February 1950, 15 years after planting. At age 15, there were about twice as many trees in active height growth on the burned plots as on the • unburned plots. For example, on "S areas planted at the rate of 1,600 trees per acre, unburned plots had only 176 trees per acre in active I height growth while bu
. The Alexandria Research Center. Forests and forestry Research. 6 years after planting, these plots were prescribe-burned to control brown spot needle disease. Wild- fires burned over them at 8 years and 17 years after planting. Another controlled burn to remove excess fuel was made in February 1950, 15 years after planting. At age 15, there were about twice as many trees in active height growth on the burned plots as on the • unburned plots. For example, on "S areas planted at the rate of 1,600 trees per acre, unburned plots had only 176 trees per acre in active I height growth while burned plots had 363. These plots are fairly typical of the difficulties that have been experienced in growing planted . §1 longleaf During the first 15 years •<^VH'V«.-' i: all plots suffered losses from town * ants, hogs that temporarily invaded I the fenced plantations, salamanders E (eastern pocket gophers), and .brown spot. Fires reduced the | stands on the burned plots, but not so much as the brown spot infection iflngpg;. on the unburned plots Figure 13. --In open-grown stands, 100 longleaf trees per acre can be pruned to a height of one log for about $5. 50. (Photo by Elemore Morgan) acre pruned to 17 feet (fig. 13); 3. - pruned to about two-thirds of the tree height. When the stands were 16 years old, three pruning treatments were applied to a total of 4, 800 rough, limby trees in the wider- spaced plots: 1. --All trees pruned up to a height of 17 feet (1 sawlog); 2. --One hundred selected trees per One hundred selected trees per acre One-log pruning required 3 man-minutes of labor for a tree 4 inches d. b. h. and 6 minutes for an 8-inch tree (which usually had larger branches). At 85 cents per hour for common labor and 25 cents per hour for transportation, supervision, and other expenses, pruning costs per tree averaged from to 11. 1 cents. - 18 -. Please note that these images are extracted from scanned page images that may have been digitally enhanced for
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Keywords: ., bookcentury1900, bookcollectionameri, bookcollectionbiodiversity
