Decay and Toughness Losses in Southern Pine Infected By Peniophera

Tests to determine the toughness losses of longleaf pine exposed to Peniophera and other fungus infection during 6 to 13 weeks of storage were made. Four longleaf pine trees, 10 to 11 inches in diameter, were selected to supply sapwood test material. Alternate 5- and 1.5- ft. bolts were cut. A total of 18 pieces of each length were used. After the sections were peeled and marked, the 1.5-ft. section served as uninfected control material. These were split lengthwise into halves to facilitate drying, then soaked for 24 hours in an aqueous fungicidal solution containing 5 percent of sodium pentachlorophenate and finally stored open-piled in a building. The 5- foot bolts were stacked in a small pile that was erected about 1 foot above the ground. The completed pile consisted of three bottom and top layers of nontested layers, with three layers of six bolts each of test material in the center. After 5, 9, and 12 weeks of storage, five or six bolts were removed from the pile, and a 2-ft. piece was cut from one end of each bolt. Before toughness tests, 1-inch disks were cut from both ends of each bolt and its control section. These disks were used for the determination of 1) the amount and type of decay in the stored bolts, and 2) possible losses in specific gravity of the bolts during storage. The amount and type of decay were ascertained by visual examination, probing, and the use of a color indicator. The specific gravity of the disks was determined from green volume and ovendried weight. Test results showed 31 percent of the cross-sectional area of the bolts stored for 6 weeks showed decay infection. Losses in specific gravity averaged less than 1 percent; 5 to 15 percent of the cress-sectional area was discolored. After 10 weeks of storage, 58 percent of the cross-sectional area showed decay, losses in specific gravity averaged about 3 percent, 5 to 25 percent of the cross-sectional area was discolored. After 13 weeks of storage, 62 percent of the cross-sectional area was decay infected, and losses in specific gravity averaged about 3.5 percent. Blue stain discoloration varied from 5 to 60 percent. The average loss in toughness was about 16 percent in the bolts stored for 6 weeks, about 27 percent for 10 weeks, and 33 percent for 13 weeks. Losses in toughness of the stored wood were not greatly different for the specimens taken from the outer and inner zones of the bolts.

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