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Effects of Aminopyralid on Ponderosa Pine (Pinus ponderosa)

Published online by Cambridge University Press:  20 January 2017

John M. Wallace*
Affiliation:
Department of Plant, Soil, and Entomological Sciences, University of Idaho, Moscow ID 83844-2339
Timothy S. Prather
Affiliation:
Department of Plant, Soil, and Entomological Sciences, University of Idaho, Moscow ID 83844-2339
Vanelle Peterson
Affiliation:
Dow AgroSciences, 28884 S. Marshall Road, Mulino, OR 97042-9704
*
Corresponding author's E-mail: [email protected]

Abstract

Invasive weed control within cleared, forested sites in the inland Northwest is complicated by the susceptibility of ponderosa pine to synthetic auxin herbicide injury, used to control broadleaf weeds. Herbicide injury may lead to decreased canopy volume and variable growth patterns of ponderosa pine, which is a commercially important tree species. Herbicide injury to ponderosa pine can be decreased with dormant-season applications, a timing suited to control many weeds that may occur within ponderosa pine sites. However, spring-timed herbicide applications are needed to control other weeds, such as meadow hawkweed, and that application timing coincides with active ponderosa pine growth. In this study, we determined the level of injury to ponderosa pine resulting from spring-timed aminopyralid, clopyralid, and picloram applications beneath ponderosa pine canopies. Herbicide injury to leader and lateral candles and needle elongation was evaluated 1 and 12 mo after treatment (MAT). Low rates of aminopyralid alone (0.05 kg ae ha−1 [3 fl oz ac−1]) and aminopyralid + clopyralid (0.05 + 0.10 kg ae ha−1) resulted in herbicide injury ratings that did not differ from untreated trees. The high rate of aminopyralid (0.12 kg ae ha−1) resulted in leader candle injury on 75% of treated trees, 5% of which were necrotic at 12 MAT. Herbicide injury was observed on 30% of lateral candles. In comparison, picloram (0.28 kg ae ha−1) treatments resulted in necrosis or mortality of leader and lateral candles on 65% and 40% of trees, respectively, at 12 MAT. Results suggest that use of low rates of aminopyralid alone or in combination with low rates of clopyralid minimizes the risk of nontarget injury to ponderosa pine (> 5 yr old) while controlling hawkweed with a spring application.

Type
Research Article
Copyright
Copyright © Weed Science Society of America 

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References

Literature Cited

Atzet, T., Wheeler, D. L., Smith, B., Franklin, J., Riegel, G., and Thornburgh, D. 1992. Vegetation. Pages 92113 in Hobbs, S. D., ed. Reforestation Practices in Southwestern Oregon and Northern California. Corvallis, OR Forest Research Laboratory, Oregon State University.Google Scholar
Carrithers, V. F., Burch, P. L., Kline, W. N., Masters, R. A., Nelson, J. A., Halstvedt, M. B., Troth, J. L., and Breuninger, J. M. 2005. Aminopyralid: a new reduced risk active ingredient for control of broadleaf invasive and noxious weeds. Proc. West. Soc. Weed Sci. 58:5960.Google Scholar
Cooper, S. V., Neiman, K. E., and Roberts, D. W. 1991. Forest habitat types of northern Idaho: A second approximation. Ogden, UT USDA-Forest Service-Intermountain Research Station GTR-INT-236. Pp. 8085.Google Scholar
Duncan, C. L. 2011. Spotted knapweed management with herbicides. TechLine News, Technotes. Article: 010-57884. URL: http://tinyurl.com/6ekvs3x. Accessed: November 15, 2011.Google Scholar
Duncan, C. L. and Clark, J. K. 2005. Invasive Plants of Range and Wildlands and their Environmental, Economical and Societal Impacts. Lawrence, KS Weed Science Society of America.Google Scholar
Enloe, S. F., Lym, R. G., Wilson, R., et al. 2007. Canada thistle (Cirsium arvense) control with aminopyralid in range, pasture and noncrop areas. Weed Technol. 21:890894.Google Scholar
Habeck, R. J. 1992. Pinus ponderosa var. ponderosa: fire effects information system. USDA-USFS-Rocky Mountain Research Station, Fire Science Laboratory. http://www.fs.fed.us/database/feis/. Accessed: December 21, 2011.Google Scholar
Jachetta, J. J., Havens, P. L., Dybowski, J. A., Kranzfelder, J. A., and Tiu, C. 2005. Aminopyralid: a new reduced risk herbicide for invasive species control: toxicology, ecotoxicology, and environmental fate profile. Proc. West. Soc. Weed Sci. 58:6061.Google Scholar
Paley, S. M. and Radosevich, S. R. 1984. Effect of physiological status and growth of ponderosa pine (Pinus ponderosa) and greenleaf manzanita (Arctostaphylos patula) on herbicide selectivity. Weed Sci. 32:395402.Google Scholar
Radosevich, S. R., Roncoroni, E. J., Conard, S. G., and McHenry, W. B. 1980. Seasonal tolerance of six coniferous species to eight foliage-active herbicides. For. Sci. 26:39.Google Scholar
Uchytil, R. J. 1991. Pseudotsuga menziesii var. menziesii. Ogden, UT: Fire Effects Information System. USDA-USFS-Rocky Mountain Research Station, Fire Science Laboratory. http://www.fs.fed.us/database/feis/. Accessed: November 15, 2011.Google Scholar
Wallace, J. M. and Prather, T. 2011. Meadow hawkweed control at various timings using aminopyralid. Spokane WA West. Soc. Weed Sci. Prog. Rep. 6 p.Google Scholar
Wallace, J. M., Prather, T., and Wilson, L. 2010. Plant community response to integrated management of meadow hawkweed (Hieracium caespitosum) in the Pacific Northwest. Invasive Plant Sci. Manag. 3:268275.Google Scholar
Western Wood Products Association, . 2010. Ponderosa Pine. http://www.wwpa.org/ppine.htm. Accessed: March 1, 2010.Google Scholar
Wilson, L. M., Prather, T., Wallace, J., and Lass, L. 2006a. Meadow hawkweed control using other selective herbicides in abandoned pasture near Santa, ID. Sparks, NV West. Soc. Weed Sci. Prog. Rep. 5 p.Google Scholar
Wilson, L. M., Prather, T., Wallace, J., and Lass, L. 2006b. Control of meadow hawkweed with aminopyralid and surfactant in abandoned pasture near Santa, ID. Sparks, NV West. Soc. Weed Sci. Prog. Rep. Pp. 67.Google Scholar