Clopyralid, picloram, triclopyr, metsulfuron, and tebuthiuron were applied to control kudzu on four loblolly pine forest regeneration sites during July 1997. Spot treatments were applied to ...recovering kudzu in June 1998 and June 1999. Soil leachate was monitored for these five herbicides from July 1997 to December 2000. All herbicides were detected in shallow (51–58 cm deep) and deep lysimeters (84–109 cm deep). Clopyralid was not persistent and limited leaching occurred, with residue levels of 0.4 to 2.8 μg L−1 in 12 of 102 deep lysimeter samples. Picloram was mobile and persisted at 0.6 to 2.5 μg L−1 in shallow and deep lysimeters for at least 10 mo after the initial application. Triclopyr residues were not persistent in shallow lysimeters and remained < 6 μg L−1 during the study. Metsulfuron persisted at < 0.1 μg L−1 for 182 to 353 d in shallow lysimeters and at < 0.07 μg L−1 for 182 to 300 d in the deep lysimeters in various plots. Tebuthiuron peaks in the deep lysimeters ranged from 69 to 734 μg L−1 34 to 77 d after the first spot treatment. In the soil that was essentially a fill area, tebuthiuron residues remained > 400 μg L−1 (402–1,660 μg L−1) in the shallow lysimeter samples and > 180 μg L−1 (181–734 μg L−1) in the deep lysimeters throughout a 354-d period that followed the first spot application. When used as part of a forest regeneration program, the relative potentials of the herbicides to move into shallow groundwater were: tebuthiuron > picloram > metsulfuron > clopyralid > triclopyr. Nomenclature: Clopyralid; metsulfuron; picloram; tebuthiuron; triclopyr; kudzu, Pueraria montana (Lour.) Merr. PUEMO; loblolly pine, Pinus taeda L. PINTA.
Three low-volume mini-sprinklers were tested for their efficacy to strip trichloroethylene (TCE) and tetrachloroethylene (PCE) from water. Deionized water spiked with TCE and PCE was pumped for ...approximately 1 h at 0.19 to 0.21 MPa (28 to 30 lb in(-2)) through a mini-sprinkler supported on top of a 1.8-m-tall riser. Water was collected in collection vessels at 0.61 and 1.22 m above the ground on support columns that were spaced at 0.61-m intervals from the riser base, and samples were composited per height and distance from the riser. Overall, air-stripping reduced dissolved concentrations of TCE and PCE by 99.1 to 100 and 96.9 to 100%, respectively, from mean influent dissolved concentrations of 466 to 1675 microg L(-1) TCE and 206 to 940 microg L(-1) PCE. In terms of mass removed, the mini-sprinklers removed TCE and PCE at a rate of approximately 1400 to 1700 and 700 to 900 microg L(-1), respectively, over a 1-h test period. Mini-sprinklers offer the advantages of (i) easy setup in series that can be used on practically any terrain; (ii) operation over a long period of time that does not threaten aquifer depletion; (iii) use in small or confined aquifers in which the capacity is too low to support large irrigation or purging systems; and (iv) use in forests in which the small, low-impact droplets of the mini-sprinklers do not damage bark and in which trees can help manage (via evapotranspiration) excess waste water.
Laboratory bioassays of southern pine beetle, Dendroctonus frontalis Zimmermann, showed that beetles exhibited regional differences in response to pheromones. Bioassays of crude pheromone extracts ...from billets infested with beetles collected from Georgia, Texas, and Virginia showed that beetles from each region had significantly higher positive responses to pheromones from their own region. Beetles from Texas showed the strongest response to a standard of frontalin, trans-verbenol, and loblolly pine turpentine, followed by beetles from Georgia and Virginia
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