Progress 10/01/06 to 09/30/11
Outputs
OUTPUTS: Poa annua biotypes continue to be a major weed problem in creeping bentgrass putting greens. Initial research with methiozolin at Auburn, AL evaluated rates ranging from 0.5 to 4.0 kg ai ha applied twice in either the spring or fall/winter months at approximately 30 d intervals. The relationship between methiozolin rate and Poa annua spp. reptans (PAR) control and creeping bentgrass injury was described with a three-parameter logistic growth model. Regression parameter estimates were used to generate response curves. A total of 4 kg ha (2 kg ha plus 2 kg ha) provided 95% or more control of PAR when applied fall/winter compared to less than 60% when applied spring. Bentgrass injury was acceptable, 30% or less, with all applications that did not exceed a total rate of 4 kg ha. Additional research at Opelika, AL and Clemson, SC evaluated two application regimes. Three fall/winter applications each at 1.12 kg ha (1.12 regime) provided 99 and 91% control of PAR at Opelika and a mixture of P. annua spp. annua (PAA) and PAR at Clemson, respectively. Six fall/winter/spring applications each at 0.56 kg ha (0.56 regime) provided 92% control at Opelika and 89% at Clemson. Creeping bentgrass quality was reduced 6 weeks after initial treatment (WAIT), more so at Opelika and with the 1.12 regime, but quality was unaffected 11 WAIT at both locations. Grid-box counts for PAR and PAA infestations from both locations confirmed visual control ratings for PAR and/or PAA. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Golf course superintendents, sports field managers PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Selectively controlling Poa annua spp. annua and spp. reptans in creeping bentgrass puttings is a major milestone for golf course superintendents throughout the United States. Research at Auburn has clearly demonstrated that Poa control can be accomplished with the herbicide methiozolin. Also reserch has demonstrated that methiozolin controls ALS-resistant Poa in hybrid bermudagrass putting greens.
Publications
- Wells, S.M., R.H. Walker, R. Rodriguez-Kabana, L.J. Simmons and J.L. Belcher (2011). Granular formulations of sodium and potassium azide for mesocriconema spp. control on a bentgrass putting green. J. of Nematropica. 41:38-40.
- Perry, D.H., J.S. McElroy and R.H. Walker (2011). Effects of soil vs. foliar application of amicarbazone on annual bluegrass (Poa annua). Weed Technol. 25:604-608.
- Doroh, Marc C., J. Scott McElroy, Edzard van Santen, and Robert H. Walker (2011). Conversion of Tifway bermudagrass stands to Zorro zoysiagrass turf using combinations of dazomet and EPTC. Weed Technol. 25:631-636.
- Doroh, M. C., J. S. McElroy, and R. H. Walker (2009). Utilizing soil sterilants to control bermudagrass and re-establish zoysiagrass for fairway renovation. USGA Turfgrass and Environmental Research Online 8(11): 1-5. Http;//usgatero.msu.edu/v08/n11.pdf
- Xiao, Li, Jason L. Belcher, and Robert H. Walker (2011). Evaluation of EPTC as a preplant soil treatment in warm-season sod production. Submitted to Weed Technology.
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Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: Methiozolin (MRC-01) is a herbicide being developed for control of Poa annua var. annua and var. reptans in various cool- and warm-season turfgrasses, including bentgrass putting greens. Replicated experiments in bentgrass managed as a golf putting were conducted in 2010. Methiozolin applied three times at 1 lb ai/A rate with application intervals of 3 to 4 weeks provided greater than 95% control of var. reptans. Bentgrass injury was slight ranging from 15 to 25%. November/December applications were better than March/April with regards to Poa efficacy and bentgrass tolerance. In other experiments methiozolin applied at 0.5 lb ai/A biweekly for three applications in December followed by three additional applications February/March provided equivalent Poa control with bentgrass injury 10% or less. Granular formulations of methiozolin were made using fertilizer and non-fertilizer carriers and evaluated for Poa control. Granular forms provided Poa control equivalent to the liquid spray formulation. Aminocyclopyrachlor was evaluated for control of cogongrass, a troublesome invasive grass infesting highway rights of ways in South Alabama and other states in the Southeast. Application was made in September/October for two consecutive years at a rate of 0.25 lb ae/A per application in replicated experiments. Seedhead suppression was greater than 98% and vegetative control ranged from 88 to 93%. Pensacola bahiagrass was the desirable turf in these experiments and injury was less than 30%. Admixtures of aminocyclopyrachlor with rimsulfuron provided slightly better cogongrass control than when rimsulfuron was excluded and bahiagrass tolerance was not affected. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Golf course superintendents, sports field managers, vegetation management personnel PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Methiozolin represents a significant breakthrough in selective control of Poa annua var. reptans, a perennial type of annual bluegrass found in bentgrass puttings. To date, no chemical has provided control of this troublesome weed as well as methiozolin. Aminocyclopyrchlor is a significant breakthrought for the selective control of cogongrass in warm season turfs common to roadsides in Alabama and the Southeast. To date, only non-selcetive herbicides were effective for control of this invasive perennial grass.
Publications
- Belcher, Jason L. and Robert H. Walker. 2010. Control of perennial Poa (Poa annua spp. reptans) with metiozolin and amicarbazone in a creeping bentgrass (Agrostis palustris) putting green. Weed Sci. Soc. of Amer., Abstracts 0-54.
- Perry, Daniel, J. Scott McElroy and Robert H. Walker. 2010. Evaluation of triazine-resistant and susceptible annual bluegrass biotypes following applications of amicarbazone and atrazine. ASA, CSSA, and SSSA 2010 International Annual Meetings, Oct. 31-Nov. 4, Long Beach, CA. http://a-c-s.confex.com/crops/2010am/webprogram/Paper60452.html
- Perry, Daniel, J. Scott McElroy, E. Van Santen and Robert H. Walker. 2010. Evaluation of amicarbazone and industry standards for annual bluegrass control and perennial ryegrass response. ASA, CSSA, and SSSA 2010 International Annual Meetings, Oct. 31-Nov. 4, Long Beach, CA. http://a-c-s.confex.com/crops/2010am/webprogram/Paper60443.html
- Wells, Sheryl, Robert H. Walker, R. Rodriguez-Kabana and L.J. Simmons. 2010. Leaching of sodium and potassium azide sources applied to native soils on establish turf. ASA, CSSA, and SSSA 2010 International Annual Meetings, Oct. 31-Nov. 4, Long Beach, CA. http://a-c-s.confex.com/crops/2010am/webprogram/Paper59121.html
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: Poa annua var. reptans is a perennial weedy grass that infests bentgrass putting greens throughout the continental U.S. Research was conducted to determine bentgrass tolerance and weed efficacy with the following: amicarbazone 0.12 lb ai/A; amicarbazone + paclobutrazole (0.12 + 0.06 lb ai/A); amicarbazone + bispyribac (0.12 + 0.022 lb ai/A); paclobutrazole 0.12 lb ai/A; bispyribac 0.022 lb ai/A. Each treatment received two fall 2008 applications (November and December) followed by two spring 2009 applications (March and April). After 228 days var. reptans was controlled 52% for amicarbazone alone; 85% for amicarbazone + paclobutrazole; 56% for amicarbazone + bispyribac; 58% for paclobutrazole alone; 17% for bispyribac alone. Bentgrass injury was unacceptable at times with the two amicarbazone tank mixes and bispyribac alone, particularly with fall applications. Cogongrass(Imperata cylindrical)is a troublesome invasive perennial grass infesting roadsides in South Alabama. Studies were conducted to evaluate seedhead suppression and control with aminocyclopyrachlor. The first study was initiated September 18, 2008 near Stockton, AL. Treatments and rates were: untreated; aminocyclopyrachlor at 0.10, 0.15, 0.20, and 0.25 lb ai/A; imazapyr at 1.0 lb ae/A; and glyphosate at 4 lb ae/A. Additional treatments were aminocyclopyrachlor at 0.10 and 0.20 lb ai/A applied twice, September 18, 2008 and again May 28, 2009. All treatments received methylated seed oil as an adjuvant. Cogongrass seedheads were suppressed 98% or greater with all herbicides 202 days after application (DAA). Bahiagrass (Paspalum notatum) injury 272 DAA was less than 24% for any treatment containing aminocyclopyrachlor, 40% with imazapyr, and 97% with glyphosate. Control of cogongrass 322 DAA was 94 and 96 % for glyphosate and imazapyr, respectively. Aminocyclopyrachlor applied twice at 0.20 lb ai/A provided 73% control, while a single application at 0.25 lb ai/A controlled cogongrass 72%. All other rates of aminocyclopyrachlor controlled cogongrass less than 53%. PARTICIPANTS: Alabama Department of Transportation provided funding for the evaluation of aminocyclopyrachlor for cogongrass seedhead suppression and control on Alabama highway rights-of-ways. TARGET AUDIENCES: Golf course superintendents, state department of transportation weed management and vegetation management specialists. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Combining amicarbazone with paclobutrazole offers the best potential to manage Poa annua var. reptans in bentgrass puttings to date. An effective program includes 2 applications in the fall followed by 2 applications in the spring. The rate of each chemical can be varied to accomplish the degree of weed control and bentgrass injury that is acceptable. Imazapyr and glyphosate provide the highest degree of cogongrass control. However, both are non-selective herbicides. Killing all the vegetation along highway rights-of-ways is not acceptable. Therefore, aminocyclopyrachlor, though less efficacious, allows for control and seedhead management for this invasive grass without destroying desirable vegetation needed for soil stabilization alone highway rights-of-ways. In some areas, it may be necessary to obtain highest control with imazapyr and/or glyphosate but follow with maintenance applications of aminocyclopyrachlor.
Publications
- McElroy, J. Scott, and Robert H. Walker. 2009. Effect of atrazine and mesotrione on centipedegrass growth, photochemical efficiency, and establishment. Weed Technol. 23(1):67-72.
- Doroh, M. C., J. S. McElroy, and R. H. Walker. 2009. Utilizing soil sterilants to control bermudagrass and re-establish zoysiagrass for fairway renovation. USGA Turfgrass and Environmental Research Online 8(11): 1-5. Http;//usgatero.msu.edu/v08/n11.pdf
- Belcher, J. and R. Walker. 2009. Annual weed control with amicarbazone and flucarbazone in warm-season turf. Proc. South. Weed Sci. Soc., Vol. 62., 190.
- Walker, R. H. And J. L. Belcher. 2009. Annual bluegrass control with amicarbazone in perennial ryegrass overseed. Proc. South. Weed Sci. Soc., Vol 62., 191.
- Wells, Sheryl, R. H. Walker and J. L. Belcher. 2009. Effects of imazapic and flazasulfuron on dallisgrass in bermudagrass turf. Proc. South. Weed Sci. Soc., Vol 62., 88.
- Flessner, M. L., J. S. McElroy and R. H. Walker. 2009. Quantification of warm-season turfgrass phytotoxicity from broadleaf control herbicides. Proc. South. Weed Sci. Soc., Vol., 62. 20.
- Walker, R.H. and J. L. Belcher, 2009. Virginia buttonweed control in hybrid bermudagrass turf, PT-026. 11th International Turfgrass Research Conference, July 26-31, 2009, Santiago, Chile.
- Belcher, J. L., G. H. Huckabay, and R. H. Walker. 2009. Doveweed germination biology and control in warm-season turfgrasses, P-031. 11th International Turfgrass Research Conference, July 26-31, 2009, Santiago, Chile.
- Perry, D. H., J. S. McElroy, and R. H. Walker. 2009. Creeping bentgrass phytotoxicity and photochemical efficiency response to amicarbazone. in. Agronomy Abstracts CD-ROM Madison, WI American Society of Agronomy, Crops Science Society of America, and Soils Science Society of America. In press. Abstract
- Wells, Sheryl, R. H. Walker, and E. A. Guertal. 2009. Sodium azide as a possible nitrification inhibitor in a bentgrass putting green. Southern Association of Agricultural Scientists (SAAS), January 31- February 3, 2009, Atlanta , GA.
- Wells, Sheryl. 2009. Granular forms of sodium and potassium azide as a nematicide for established turfgrasses. Auburn University Theses and Dissertations. Http://hdl.handle.net/10415/1712
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: MSMA is an organic arsenical herbicide and EPA eliminated and/or severely restricted uses at end of 2008. Therefore, studies were conducted with the objective of finding MSMA replacements for control of dallisgrass. Results showed glyphosate applied September - November provided excellent control with minimum damage to the hybrid bermudagrass turf. Roundup Pro at 5 to 8 fluid ounces of product/acre applied in September and repeat application following 3 weeks later provided control 90% or greater. Sequential application of flazasulfuron, foramsulfuron, sulfosulfuron, or trifloxysulfuron the spring following fall glyphosate application controlled or severely suppressed any dallisgrass escapes. Results reported at Inter. Weed Sci. Soc., South..Weed Sci. Soc., AL Turfgrass Assn.. Sodium azide has been extensively studied the past 4 years as a replacement for Nemacur nematicide in hybrid bermudagrass and creeping bentgrass turf. Sodium and potassium azide were impregnated onto Profile fired clay and Biodac cellulose-based carriers and applied to golf putting greens. Hybrid bermudagrass tolerance was approximately twice that of creeping bentgrass. But, programs of low rates and repeat applications were tested and all provided excellent control of sting, dagger, lance and ring nematodes. Little turf injury occurred when application was made to dry turf and irrigation followed immediately after application. Two applications were sufficiently efficacious for nematode control in bermudagrass while lower rates on bentgrass required three applications. There was no advantage for using potassium azide over the cheaper sodium salt. Results were presented at turfgrass field days and results reported at South. Weed Sci. Soc. and American Soc. Agron. Ann. Conf. American Pacific Corp. continues to pursue EPA registration. Research in 2008 evaluated acrolein applied pre-transplant (PRE) or post-transplant (POST) in strawberry. Results showed all POST applications resulted in significant reductions in plant vigor and yield. Strawberries receiving acrolein at 400 lb/A PRE produced significantly higher total yield than methyl bromide, fungicides only, and non-treated. Acrolein was researched in a tomato study that evaluated efficacy under standard high density polyethylene (HDPE) mulch and virtually impermeable film (VIF). Yellow nutsedge control provided by methyl bromide was higher under VIF than HDPE. Inline (1,3-D + chloropicrin) followed a similar pattern, providing 100% control under VIF and 0% under HDPE. Nutsedge control within acrolein rates was similar regardless of mulch type. No differences in tomato yield among chemicals or between mulches. There was no value to using more expensive VIF mulch with acrolein application. Efficacy of Inline was significantly improved with the use of VIF. Results presented at the 2008 MBAO Conf. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Golf course superintendents, turfgrass managers, tomato and strawberry producers. PROJECT MODIFICATIONS: Need EPA approval of sodium azide and acrolein.
Impacts
Replacing MSMA with glyphosate for selective control of dallisgrass in bermudagrass turf will allow for use of a more environmentally friendly herbicide. Three applications of MSMA were required for control whereas two applications of glyphosate will provide equal efficacy. Replacing Nemacur with sodium azide for nematode control on hybrid bermudagrass and creeping bentgrass putting greens and other turf areas is needed. Sodium azide shows excellent potential but its fate is in the hands of EPA. Acrolein in combination with herbicides has shown excellent potential for pest control in tomato, bell pepper and strawberry as a methyl bromide replacement. Acrolein also is an excellent promoter of Tricoderma spp. which provides biological control of disease organisms.
Publications
- Belcher, J. L. (2008). Acrolein (2-propenal): A Potential Alternative to Methyl Bromide. Doctoral dissertation, Auburn University, 2008.
- Huckabay, G. H. (2008). Tufted Lovegrass (Eragrostis pectinacea) and Doveweed (Murdannia nudiflora) Control in Warm-Season Turfgrasses. Master's thesis, Auburn University, 2008.
- Belcher, J. L. and R. H. Walker. Strawberry and tomato response to acrolein. Proceedings 2008 Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions, p. 50-1.
- Simmons, L. J., R. Rodriguez-Kabana, J. L. Belcher, and R. H. Walker. Effects of drip-applied acrolein on natural soil populations of Tricoderma and Fusarium. Proceedings 2008 Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions, p. 52-1.
- Belcher, J. L., R. H. Walker, and J. S. McElroy. Centipedegrass response to mesotrione applied alone and in combination with atrazine, paper 413. Proceedings 5th International Weed Science Congress, Vancouver, Canada, 23-26 June 2008.
- Walker, Robert and Jason Belcher. Fall applications of glyphosate for selective control of dallisgrass in hybrid bermudagrass turf, paper 419. Proceedings 5th International Weed Science Congress, Vancouver, Canada, 23-26 June 2008.
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Progress 01/01/07 to 12/31/07
Outputs
Doveweed (Murdannia nudiflora)is an emerging problem in warm-season turf and is spread primarily through seed propagules. It is also a documented problem in container-grown ornamentals further increasing its geographical distribution. Good to excellent control with atrazine is well documented but this treatment is limited to centipedegrass and St. Augustinegrass. Effective control of doveweed infestations in bermudagrass and zoysiagrass turfs is lacking. Preliminary research at Auburn has shown herbicides containing MCPA ester provided acceptable levels of control (87 percent). Therefore, phenoxy acetic and propionic herbicides containing methyl-chloro substitution and 2,4-D + 2,4-DP were evaluated for control of doveweed in greenhouse and field experiments. Greenhouse: Two-inch diameter plugs of doveweed were transplanted into 0.5-L cups of soil and allowed to grow for 6 weeks before treating with herbicides. Herbicides evaluated were: MCPP-p 4 Amine, MCPA LV 4 Ester,
Rhomene (MCPA amine), Horsepower (amines MCPA, triclopyr, dicamba) and Turf Weed & Brush (esters 2,4-D and 2,4-DP). Single application rates evaluated were 0.5, 1.0 and 2.0 lb ae/A. A sequential application was applied 3 week after the initial. Each treatment was replicated four times and two separate experiments were conducted. Herbicides were applied with a track sprayer in a final volume of 30 GPA. A non-ionic surfactant was included. Visual percent control ratings were taken every 14 days. Five weeks after the second application treatments totaling 4 lb ae/A (2 lb + 2 lb) of Horsepower, Turf Weed & Brush, MCPP-p 4 Amine, MCPA LV 4 Ester, and Rhomene provided 99, 99, 98, 93 and 75 percent, respectively. Rates totaling 2 lb ae/A (1 lb + 1 lb) of Turf Weed & Brush, Horsepower, MCPA LV 4, MCPP-p-4 Amine, and Rhomene provided 89, 88, 80, 72, and 23 percent, respectively. Atrazine applied twice at 1.5 lb ai/A provided 99 percent. Field: A field experiment in an area with a natural
infestation of doveweed was used as the experimental site. The 4 lb ae/A (2 lb + 2 lb) rate of all herbicides was not evaluated in the field experiment due to space limitations. Treatments were arranged in a randomized complete block design and were replicated three times. Individual plot size was 3 by 5 feet. Herbicides were applied with a CO2 backpack sprayer in a water volume of 30 GPA. Non-ionic surfactant was included. The first application was made on 8/4 and the second on 8/25. Five weeks after the second application, treatments totaling 2 lb ae/A (1 lb + 1 lb) of Horsepower, MCPP-p 4 Amine, Turf Weed & Brush, Rhomene, and MCPA LV 4 Ester provided 99, 98, 96, 86, and 73 percent control, respectively. Treatments totaling 1.0 lb ae/A (0.5 lb + 0.5 lb) of Horsepower, Turf Weed & Brush, MCPP-p-4 Amine, Rhomene, and MCPA LV 4 Ester provided 99, 83, 82, 56, and 48 percent control, respectively. Atrazine applied twice at 1.5 lb ai/A provided 100 percent control.
Impacts
Information can be used by both homeowner and professional turfgrass managers to control doveweed in hybrid bermudagrass and zoysiagrass turfs and thus improve turf aesthetics.
Publications
- Simmons, L.J., R. Rodtiguez-Kabana, J.L. belcher and R.H. Walker. The effects of acrolein on the microbiology and key biochemical activities of the soil. Prod. 2007 Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions, MBAO.org.
- Richardson, M. D., K. W. Hignight, R. H. Walker, C. A. Rodgers, D. Rush, J. H. McCalla and D. E. Karcher. 2007. Meadow fescue and tetraploid perennial ryegrass: two new species for overseeding dormant bermudagrass turf. Crop Sci. 47:83-90.
- Richardson, Mike, Kenneth Hignight, Harold Walker, Charlie Rodgers, Debra Rush, John McCalla, Doug Karcher. 2007. New species for overseeding dormant bermudagrass. Golf Course Management 75 (5):126-130.
- Huckabay, George H., Robert H. Walker and Jason Belcher. 2007. Tufted lovegrass (Eragrostis pectinacea) control in zoysiagrass turf. Proc. South. Weed Sci. Soc. 60:101.
- Huckabay, George H., Robert H. Walker and Jason Belcher. 2007. Doveweed (Murdannia nudiflora) control with POST herbicides. Proc. South. Weed Sci. Soc. 60:104.
- Wells, Sheryl, R.H. Walker, J.L. Belcher, R. Rodriguez-Kabana, L. Simmons and W.T. Crow. Granular forms of Na and K azides applied to established turf. Proc. 2007 Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions, MBAO.org.
- Belcher, Jason, R.H. Walker, R. Rodriguez-Kabana, and L.J. Simmons. Tomato and nutsedge response to acrolein and herbicides applied preplant. Proc. 2007 Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions, MBAO.org.
- Walker, R.H., J.L. Belcher, E. Guertal, and R. Rodriguez-Kabana. Replacements for methyl bromide in a centipedegrass based sod rotation system. Proc. 2007 Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions, MBAO.org.
- Wells, S., L.J. Simmons, R.H. Walker, and R. Rodriguez-Kabana. Leaching of Na ad K azide granules applied to established turf. Proc. 2007 Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions, MBAO.org.
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Progress 01/01/06 to 12/31/06
Outputs
Tufted lovegrass (Eragrostis pectinacea) has been identified as a problem in sod production in MS, TN, AR, GA and AL, particularly in zoysiagrass. Slow growth rate of zoysiagrass has been suggested as a contributing factor. Seed germination response to temperature and light (Huckabay and Walker) showed light was required and germination occurred over a wide temperature range. Boyd and Rodgers showed that glyphosate (Roundup Pro) at 0.31lb ae/A could be used to selectively remove this weed from Meyer zoysiagrass. Walker evaluated glyphosate 0.28 lb ae/A applied twice to Meyer zoysiagrass. Tufted lovegrass control was excellent but turf injury averaged 35%. Currently, repeat applications of glyphosate at 0.10 to 0.14 lb ae/A are being used to managed this troublesome weed in zoysiagrass. However, producers are concerned with zoysiagrass injury, particularly to cultivars that have wider leaf blades. Tufted lovegrass has now been identified as a problem in bermudagrass
and centipedegrass and tolerance to glyphosate is less with these turf species, particularly centipedegrass. Recently, Huckabay and Walker found that repeat POST applications of mesotrione provided good to excellent control of tufted lovegrass and thus research was expanded summer 2006. In small-plot, replicated experiments, mesotrione rates of 0.032, 0.064, 0.125, and 0.25 lb ai/A were applied 1, 2, or 3 times to a recently harvested Meyer zoysiagrass turf infested with tufted lovegrass. Applications were made in the summer of 2006 on 6/11, 7/10 and 8/21. A single application of 0.25 lb ai/A provided complete control of lovegrass but turf injury was unacceptable. Three applications of 0.064 and 0.125 lb ai/A provided 78 and 98% control, respectively. Turf injury averaged 12 and 27, respectively. Zoysiagrass injury was in the form of foliar bleaching and slowed growth. Similar studies were conducted on 2- to 4-leaf common centipedegrass. Mesotrione rates as shown above were applied
two times alone and with atrazine at 0.25 lb ai/A. Interval between applications was 3 weeks. Two applications of mesotrione at 0.125 lb ai/A provided 99% control when evaluated 5 weeks after the second application. A single application of mesotrione + atrazine (0.0625 + 0.25 lb ai/A) provided 99% control when evaluated 8 weeks after treatment. Atrazine at 0.25 lb ai/A applied twice provided only 13% control of tufted lovegrass. Centipedegrass tolerance to mesotrione is excellent. Previous research by McElroy and Walker showed excellent tolerance when applied to 2-leaf centipedegrass.
Impacts
Implementation of new technology for turfted lovegrass control in warm-season sod production should reduced applications of marginally effective herbicides, improve sod quality and increase profits by 5 to 8%.
Publications
- Dane, J. H., R. H. Walker, L. Bahaminyakamwe and J. L. Belcher. 2006. Tall fescue and hybrid bluegrass response to soil water matric head limits. Agricultural Water Management 86:177-186.
- Ni, Hanwen, Glenn Wehtje, Robert H. Walker, Jason Belcher and Eugene K. Blythe. 2006. Turf tolerance and Virginia buttonweed (Diodia virginiana) control with fluroxypyr as influenced by the synergist diflufenzopyr. Weed Technol. 20(2): 511-519.
- Richardson, M. D., K. W. Hignight, R. H. Walker, C. A. Rodgers, D. Rush, J. H. McCalla and D. E. Karcher. 2007. 2007. Meadow fescue and tetraploid perennial ryegrass two new species for overseeding dormant bermudagrass turf. Crop Sci. 47:83-90. Published on line January 22, 2007.
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