Wingate, NC, United States
Wingate, NC, United States

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Enloe S.F.,University of Florida | Lauer D.K.,Silvics Analytic
Weed Technology | Year: 2015

Macartney rose is an aggressive, thorny shrub that suppresses forage production and strongly hinders cattle grazing in southern pastures. Previous studies have found this weed to be extremely difficult to control with most pasture herbicides. We conducted two studies in central Alabama to assess several new herbicide chemistries applied at spring, early fall, and late fall timings. In the first study, we compared aminocyclopyrachlor, tank mixed with either 2,4-D, triclopyr, metsulfuron, or chlorsulfuron, with the commercial standard, picloram + 2,4-D. In the second study, we compared aminopyralid, tank mixed with either 2,4-D or metsulfuron and triclopyr + fluroxypyr, to the commercial standard, picloram + 2,4-D. Aminocyclopyrachlor + chlorsulfuron or metsulfuron and aminopyralid + 2,4-D or metsulfuron provided acceptable control and were comparable to picloram + 2,4-D at the early fall timing. Macartney rose control with treatments applied at the late fall timing tended to be less than commercially acceptable levels. We found that no herbicide treatment controlled Macartney rose at the spring timing. In addition, triclopyr + fluroxypyr did not control Macartney rose at any application timing. These results indicate that the early fall timing was optimal and that both aminocyclopyrachlor and aminopyralid can provide good Macartney rose control when mixed with certain other herbicides, including metsulfuron. Nomenclature: 2,4-D; aminocyclopyrachlor; aminopyralid; chlorsulfuron; fluroxypyr; metsulfuron; picloram; triclopyr; Macartney rose, Rosa bracteata J.C. Wendl ROSBC.


Minogue P.J.,University of Florida | Enloe S.F.,Auburn University | Osiecka A.,North Florida Research and Education Center | Lauer D.K.,Silvics Analytic
Invasive Plant Science and Management | Year: 2011

Kudzu is an invasive perennial climbing vine characterized by fast growth rates and tolerance to control measures. Repeated applications with high rates of 2,4-D plus picloram provide effective kudzu control, but picloram use is not permitted in certain states due to groundwater pollution concerns. Studies were conducted in Alabama and Florida to compare kudzu control with aminocyclopyrachlor, a new herbicide, to control provided by aminopyralid, clopyralid, metsulfuron methyl, and picloram plus 2,4-D, which are common treatments for kudzu management. Two annual applications of the same herbicide treatment were evaluated for effects on kudzu cover, kudzu volume index, and cover of other vegetation. Aminocyclopyrachlor at 140 to 280 g ae ha -1 (2 to 4 oz ae ac-1) was as effective as the standard 4.48 kg ae ha-1 (4 lb ae ac-1) 2,4-D amine plus 1.2 kg ae ha-1 picloram for kudzu control. There were no differences in kudzu control among the three rates of aminocyclopyrachlor tested. Colonization by graminoids, forbs, and Rubus spp. at 2 yr was greatest for herbicides providing the best kudzu control: aminocyclopyrachlor, and 2,4-D plus picloram. Herbicide treatments were more effective in controlling kudzu at the Alabama location, but repeated annual applications for 2 yr did not completely eliminate kudzu with any treatment at either site. © Weed Science Society of America.


Enloe S.F.,Auburn University | Kline W.N.,Dow AgroSciences | Aulakh J.S.,Auburn University | Bethke R.K.,Auburn University | And 2 more authors.
Invasive Plant Science and Management | Year: 2013

Macartney rose is an aggressive thorny shrub that displaces forage species and hinders cattle grazing in rangelands and pastures of the southern United States. Historically, Macartney rose has proven to be extremely difficult to control even with high rates of soil residual herbicides such as picloram. Recent advances in herbicide chemistry warrant testing on this troublesome species. We compared mowing and late summer broadcast applications of thirteen herbicide treatments that included combinations of aminopyralid, fluroxypyr, metsulfuron, picloram, triclopyr, and 2,4-D. Treatments were applied to the same rose clumps for 2 consecutive yr. An additional mowing was done to one half of the rose clumps in each treatment 6 mo after the second herbicide treatment. At 11 mo after initial treatment (MAIT), mowing and all herbicide treatments performed very poorly and provided 35% control or less. At 12 mo after retreatment (24 MAIT), picloram + 2,4-D and aminopyralid + metsulfuron, both followed by mowing, were the most effective treatments, providing 72 to 91% control. All other treatments provided less than 70% control. However, complete clump mortality was very low across all treatments, ranging from 3 to 32%. These results indicate that Macartney rose suppression is possible with certain new herbicides, but complete clump kill is still lacking. © 2013 Weed Science Society of America.


Minogue P.J.,University of North Florida | Miller J.H.,U.S. Department of Agriculture | Lauer D.K.,Silvics Analytic
Southern Journal of Applied Forestry | Year: 2012

Cogongrass (Imperata cylindrica [L.] P. Beauv. var. major [Nees] C.E. Hubb) is one of the most invasive perennial grasses worldwide and has progressively infested managed and natural habitats in the mid-South over the past 100 years. To extend past research toward the goal of eradication on forested sites, we tested the most effective herbicides (glyphosate and imazapyr) over a 3-year study period in a series of low to very high rates at two application timings, all followed by one retreatment a year later. A commonly used combination of glyphosate and imazapyr was also tested at three spray volumes. Factorial studies were established at two sites in the Coastal Plain of Alabama involving new or old infestations. Herbicide efficacy, measured 24 months after treatment and retreatment, increased linearly with increasing rates of glyphosate and imazapyr, but eradication was not achieved. On average, September applications provided greater control than October applications at both sites (61 versus 50%, respectively). The best levels of control 2 years after retreatment occurred with repeated September applications using 2.2 kg acid equivalent/ha imazapyr, providing 88 and 90% control in the new and old infestations, respectively. Control with the glyphosate and imazapyr combination did not differ with spray volumes, but the combination gave greater control than similar rates of the single herbicides on the new infestation. Copyright © 2012 by the Society of American Foresters.


Minogue P.J.,University of North Florida | Bohn K.K.,University of West Florida | Osiecka A.,University of North Florida | Lauer D.K.,Silvics Analytic
Invasive Plant Science and Management | Year: 2010

Japanese climbing fern (Lygodium japonicum) is an invasive vine that has been identified as an economic and ecological threat in forest ecosystems of the Southeast. In two separate studies, we examined the use of directed sprays of glyphosate, imazapyr, and metsulfuron-methyl herbicides, alone and in combination, for control of Japanese climbing fern and for impacts to associated vegetation in mixed bottomland hardwoodcypress forests at two first terrace sites of the Apalachicola River in north Florida. Two yr after treatment, various rates of glyphosate alone generally provided greater percent control (84 to 95%) than imazapyr alone (-25 to 86%) or metsulfuron-methyl alone (-5 to 53%). Combinations of 2% glyphosate and imazapyr and/or metsulfuron-methyl resulted in 81 to 97% control at 2 yr after treatment, with no significant differences among the combination treatments or 2% glyphosate alone. Change in percent cover of associated vegetation groups was not influenced by treatment except for one location where graminoid cover increased 1 yr after metsulfuron-methyl treatment but decreased after imazapyr or glyphosate application. Species richness of dominant understory vegetation remained nearly constant at both locations regardless of treatment. These data indicate that glyphosate alone or in combination with imazapyr or metsulfuron-methyl will provide effective, although not complete, control of Japanese climbing fern, and that directed herbicide sprays minimally impact nontarget vegetation. © Weed Science Society of America 2010.


Lauer D.K.,Silvics Analytic | Kush J.S.,Auburn University
Southern Journal of Applied Forestry | Year: 2010

A dynamic site equation derived using the generalized algebraic difference approach was developed for thinned stands of natural longleaf pine (Pinus palustris Mill.) in the East Gulf region of the United States using 40 years of measurements on 285 permanent plots. The base model predicts height growth of trees once they reach 4.5 ft and was fit using a varying parameter for each tree and global parameters that are constant for all 3, 267 trees. Parameters were estimated in one step using the dummy variable approach and a first-order autoregressive error term to account for serial correlation. The final base-age invariant equation allows the user to specify the number of years required for trees to reach 4.5 ft in height. © 2010 by the Society of American Foresters.


Wyckoff G.W.,Plum Creek Timber Company | Lauer D.K.,Silvics Analytic
Forest Science | Year: 2014

Responses to operational thinning treatments were compared through the second thinning in four red pine (Pinus resinosa Ait.) stands with site indices ranging from 66 to 90 ft (base age 50 years) and first entry ages ranging from 19 to 27 years. First-thin treatments consisted of a row thin combined with an operator select crown thin that removed 1 in every 5 trees in leave rows at all locations, row thin only at two locations, and several other treatments specific to location. The second-thin treatments were performed 7-8 years after the first thin to leave a residual basal area of 89-99 ft2/ac. Total stand basal area growth between thins did not differ because of the type of thin nor between thinned and unthinned treatments. Merchantable volume growth was usually less for thinned treatments, and there was a lower percent yield in the higher product class for the first thin. There was a general pattern for growth in thinned treatments to be initially less than that in unthinned treatments and then increase with years since thinning. The more intense thin treatments had the largest diameter responses, and the second entry could probably be delayed several years with no loss of growth by following current basal area management guidelines. © 2014 Society of American Foresters.


Grant
Agency: Department of Agriculture | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 60.77K | Year: 2015

Expansion and restoration of the longleaf pine timber type is highly dependent on outreach to non-industrial private forests and landowners. Over 60% of longleaf or longleaf-oak timber types are in non-industrial private ownership. Private consultants and state foresters provide much of the technical advice and services to private landowners within the longleaf pine range. Longleaf pine ecosystems are resilient to climate change, sequester carbon, and management practices (early thinning) can provide biomass as an alternative energy source but management is more complex than for other southern pine species. The complexities of longleaf regeneration, inability to fully understand future production of diverse products over long rotations, uncertainty of longer investment periods for higher-valued wood products, and lower short-term wood volume productivity are major limitations to establishment and maintenance of the longleaf pine type. A decision support system that improves the ability of professional foresters, managers, and landowners to accurately characterize long-term expectations from longleaf pine with respect to their interests and with respect to the potential to realize and utilize a more diverse output of products would help overcome some of these limitations.Currently, a major limitation to implementation of a longleaf pine decision support system is the availability of size-class models for long rotations (up to 120 years) that allow construction and projection of stand tables, thinning, and merchandizing of products. The technical hurdle addressed here, in Phase I, is the development and testing of stand table projection techniques similar to those that have been developed for other pine species. An important aspect of this approach is that it uses over 40 years of existing USDA Forest Service research study data to develop models that facilitate the application of this information to applied management decisions by public interests.

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