Variation of Cellular Proportions in Sweetgum and their Relation to Other Wood Properties

Sweetgum trees from natural stands in Louisiana were sampled along both vertical and radial gradients. From these samples, within-tree variation of cellular proportion has been established. Overall means indicate that vessels comprise 56.6% of the wood, fibers comprise 25.2% of the wood, and parenchyma comprises 18.1% of the wood. Regression analyses using fiber or vessel proportion provided curves that offer predictive capacities with high precision. In sweetgum, fiber proportion generally increases, and vessel proportion generally decreases with increasing height while parenchyma proportion remains relatively unchanged. The same trends were observed in later years of deposition

Use of Carfentrazone for Control of Natural Pine in Forestry Site Preparation Areas

Carfentrazone was applied in combination with imazapyr alone and three-way mixes with imazapyr and glyphosate to evaluate efficacy of natural pine control during site preparation activities. Results from four sites (two in MS, and one each in TX and SC) indicated that carfentrazone could assist in the control of small pine seedlings (less than six inches tall), but the control provided was not at a level considered acceptable for operational purposes. Larger pine seedlings (greater than one foot tall) were not adequately controlled by any of the treatments and shielding by other vegetation was an important factor in the control of smaller pine seedlings. Carfentrazone is not labeled for use in forestry applications and results from this study did not provide any rationale for pursuit of such labeling

Split-season herbaceous weed control for full-season seedling performance

Results from four loblolly pine (Pinus taeda L.) sites, one in each of MS and TX in 2001 and again in 2002, are presented. Twelve herbicide treatments and an untreated check were tested. Herbicide treatments were applied early (mid- March), late (mid-May), both timings, or not at all to achieve, early- late-, full-season, or no weed control. When averaged across all four sites and compared to the early treatment, bare ground was less from April through July and April through November on late treated and untreated plots, respectively. Full-season weed control provided numerically more bare ground than other treatments. When averaged across sites and compared to the early treatment, survival, total heights at ages one and two, and ground line diameters at age one were less on other treatments. Results are biologically important to managers. Many of the herbicide treatments tested can be applied early or late for the same cost but achieve excellent herbaceous weed control at different portions of the growing season. Early weed control consistently provided numerically more seedling performance than other treatments

OUSTAR: A Premixed Blend of Velpar DF+OUST XP for Herbaceous Weed Control and Enhanced Loblolly Pine Seedling Performance

Six tests were established comparing the herbaceous weed control (HWC) and resultant loblolly pine (Pinus taeda L.) seedling performance from treatments of Oustar (0, 10, 13, 16, 19 ounces product acre-1), and industry standards (Velpar L+Oust 32+2; Arsenal+Oust 4+2 both in ounces product acre-1). Sites were prepared prior to planting with: burn only, chemical only, mechanical only, or mechanical and chemical methods. Oustar (13 ounces) and industry standards provided similar weed control and seedling performance. The low rate (10 ounces) of Oustar applied to sandy loam soils receiving chemical preparation and plowing prior to planting provided bareground comparable to industry standards. When averaged across test sites, herbicide plots consistently had more bareground than untreated plots by nearly 2x 30 days after treatment (DAT), 3x 60 DAT, 4x 90 DAT, and 5x 120 DAT. Similarly, herbicide plots had more seedling survival (9 percent), total height (0.69 feet), ground line diameter (0.26 inch), and volume index (1.54 cubic feet) than untreated plots

Experimental and Theoretical Studies of the Environmental Sensitivity of the Absorption Spectra and Photochemistry of Nitenpyram and Analogs

Neonicotinoid (NN) pesticides have widespread use, largely replacing other pesticides such as the carbamates. Hence, there is a need to understand their environmental fates at a molecular level in various media, especially water. We report here the studies of a nitroenamine NN, nitenpyram (NPM), in aqueous solution where the absorption cross sections in the actinic region above 290 nm are observed to dramatically decrease compared to those in nonaqueous solvents. Quantum chemical calculations show that addition of a proton to the tertiary amine nitrogen in NPM breaks the conjugation in the chromophore, shifting the absorption to shorter wavelengths, consistent with experiment. However, surprisingly, adding a proton to the secondary amine nitrogen leads to its immediate transfer to the NO2 group, preserving the conjugation. This explains why the UV absorption of ranitidine (RAN), which has a similar chromophore but only secondary amine nitrogens, does not show a similar large blue shift in water. Photolysis quantum yields in aqueous NPM solutions were measured to be φ = 0.18 ± 0.07 at 254 nm, (9.4 ± 1.6) × 10-2 with broadband radiation centered at 313 nm and (5.2 ± 1.1) × 10-2 for broadband radiation centered at 350 nm (errors are 2σ). The major products in aqueous solutions are an imine that was also formed in the photolysis of the solid and a carboxylic acid derivative that is unique to the photolysis in water. Combining the larger quantum yields in water with the reduced absorption cross sections results in a calculated lifetime of NPM of only 5 min at a solar zenith angle of 35°, typical of 40°N latitude on April 1. The products do not absorb in the actinic region and hence will be long-lived with respect to photolysis

A Note on Within-Tree Variation of Specific Gravity in Sweetgum (Liquidambar Styraciflua L.)

Both radial and vertical variations of specific gravity within trees for sweetgum were analyzed. Upland and bottomland sites were studied. Six different sites (three upland and three bottomland) were selected; three dominant or codominant trees per site were chosen. In general, specific gravity was found to be a highly variable property of sweetgum wood. It fluctuates with both height and year of deposition, but the patterns were not consistent either within or among trees

Use of aminocyclopyrachlor for forestry site preparation in the Southeastern U.S.

It is not often that new chemistry is made available for use in forestry applications. Aminocyclopyrachlor is a new active ingredient which may have usefulness as a forestry herbicide. Research using this active ingredient began in 2005 and is continuing in university projects across the South. Both hardwood control efficacy and pine tolerance have been evaluated in these trials. A total of 60 different treatments have been evaluated for use in site preparation applications in Mississippi and Texas. This herbicide is effective on a number of species including some invasive exotics. It will probably not be a stand alone treatment, but could be useful in tank mix applications

Effects of treatments using MAT-28 for pine site preparation

Site preparation for pine plantation establishment continues to be the principal use of herbicides in the South. Due to the timing of the work and the cost involved, these applications are critical in both biological and economic terms. In an effort to improve performance in both considerations, a study was undertaken to evaluate a number of herbicide compounds in site preparation applications. A total of 12 treatments were applied with three replications on three sites in a randomized complete block design. Applications were completed in mid-July using a total spray volume of 15 gpa. Treatments included MAT-28 applied alone at three rates and MAT-28 applied in combination with metsulfuron, imazapyr, glyphosate, or sulfometuron. An assessment of hardwood control was evaluated at one year after treatment. Results from all evaluations indicated that MAT-28 applied alone did not control the principal species on these study sites very well. Mixtures with imazapyr and glyphosate provided excellent control of hardwoods

Analysis of the Cost of Emergency Managers\u27 Meeting Load: A Hampton Road Case-Study

Preparation for a disaster is not something that can be done by a single organization thus there is a need for coordination between them. Meetings and joint exercises are one means of coordination used by the emergency management community. Meetings and exercises take time, including transportation of personnel and arrangements, and time is money. With limited budgets, emergency managers need to make hard decisions about how their time is allocated. This paper describes a cost model for meeting analysis and discusses a case study that looks at the holistic time spent on meetings and exercises, by personnel, for the Hampton Roads Region of Virginia. A novel way is used to display this expenditure, e.g., it is shown in terms of monetary cost instead of temporal cost. This analysis highlighted some unexpected results, i.e., the small number of personnel involved in multiple working group meetings and high level of travel costs between the HR and the state capital, Richmond. This cost model approach may provide emergency managers with better mechanisms to show their meetings costs to senior leadership

Fifth-year pine growth response to woody release treatments in young loblolly plantations

Across the South, many forest land managers may opt to use mechanical site preparation, especially when soil treatments are deemed appropriate. While these mechanical treatments may be highly effective at addressing a particular soil problem or debris issue, they are typically less effective at control of competing vegetation. In these scenarios where pines are planted, a woody release treatment using herbicides is usually applied at the end of either the first or second growing season. The purpose of these applications is to provide long-term control of the woody competitors with typically short-term control of any herbaceous species on the site