Butler, T. J.

Interrante, S. M.

English

Texas A&M University

Effect of various herbicides on yield of established 'Coastal' bermudagrass

Texas A&amp;M Repository

    PUBLICATIONS 2003 http://forageresearch.tamu.edu Forage Research in Texas 2003. CPR-5267 EFFECT OF VARIOUS HERBICIDES ON YIELD OF ESTABLISHED ‘COASTAL’ BERMUDAGRASS.  T.J. Butler and S.M. Interrante. Texas A&M University Research and Extension Center, Stephenville.   Summary and Application Several new herbicides have been labeled for pasture weed control, however their effect on ‘Coastal’ bermudagrass [Cynodon dactylon (L.) Pers.] dry matter (DM) yield is not well documented. The objective of this study was to determine the effect of some “newer” herbicides [Starane (fluroxypyr), Remedy (triclopyr), Redeem R&P (triclopyr + clopyralid), Pasturegard (triclopyr + fluroxypyr), LAF004 (picloram + fluroxypyr), Envoke (trifloxysulfuron), and Plateau (imazapic)] on ‘Coastal’ bermudagrass DM yield, and to compare them to traditional pasture herbicides.  Cimarron Max, 2,4-D LV6, Fuego, Reclaim, and Weedmaster did not reduce yields in any harvest.  Envoke and Grazon P+D reduced yield only in the first harvest, 2001 (low rainfall year), but not in 2002 (higher rainfall year).  Remedy, Redeem, PastureGard, and Plenum reduced yield in the first harvest both years, but did not reduced total DM yield in either year. Tordon 22K and Starane reduced DM yields in the first harvest and total harvests both years. Plateau reduced DM yields in all harvests both years.  Introduction  Weeds compete with pasture plants for moisture, light, and nutrients.  It is estimated that every lb of weed reduces the production of forage by an equal amount.  Weeds can also reduce the quality and value of hay.  It is important to control weeds in order to maximize forage production and quality.  Herbicides used for forage and pasture management should provide effective weed control without negatively affecting forage growth and yield. Research indicates that herbicides such as 2,4-D amine, dicamba, ‘picloram + 2,4-D amine’ (Grazon P+D), and ‘dicamba + 2,4-D amine’ (Weedmaster) applied to established Coastal bermudagrass for post-emergent weed control had no inhibitory effects on forage quality or yield (1, 2, 3). However, picloram applied during periods of low rainfall has been found to severely reduce the density and yield of ‘Coastal’ bermudagrass (1).   The objective of this study was to determine the effect of newer herbicides Starane, Remedy, Pasturegard, LAF004, Redeem R&P, Envoke, and Plateau on DM yield of ‘Coastal’ bermudagrass, and to compare them to traditional pasture herbicides.    Methods and Materials  A randomized complete block design experiment with three replications was initiated on fully established Coastal bermudagrass during the 2001 and 2002 growing seasons in Stephenville, TX.  The herbicides and application rates evaluated in this study are listed in Table 1. In 2001, Plateau treatments were made to dormant bermudagrass on 15 March and all herbicide treatments were applied to actively growing bermudagrass on 19 April.  In 2002, Plateau treatments were applied to dormant bermudagrass on 15 February and all herbicide treatments were applied to http://forageresearch.tamu.edu Forage Research in Texas 2003. CPR-5267 actively growing bermudagrass on 19 April.  All herbicide treatments were made using a backpack CO2 sprayer delivering 15 gallons per acre (GPA).  All plots were fertilized with 100 lb N/A and 40 lb P2O5 (recommended according to soil test) in late April, and an additional 100 lb N/A was applied after each harvest.  Yields were estimated by harvesting 3.5 by 20 ft from each plot throughout the growing season when sufficient growth was present (approximately monthly intervals).  Samples were dried at 120° F for 48 hr and yields are reported as lb DM/A.  Year 2001, which was considered to be a low rainfall year, only received 7.59 in rainfall during April – August; Year 2002, which was considered to be a normal year, received 16.06 in rainfall from April – August compared to the 30 yr average of 15.03 in for the same time period.  Table 1. Herbicide product names, chemical names, rates, and active ingredient (a.i.) used in this study.   † Cimarron Max was only applied in 2002. ‡ Envoke is not currently labeled for pastures, but may be in the future. § Paturegard and LAF004 are awaiting EPA clearance and should be available in late 2003. ¶ In this study, Remedy was considered a new pasture herbicide due to lack of published data on its effect on Coastal bermudagrass. # The maximum labeled rate for each herbicide was used to verify the effects on Coastal bermudagrass, which may not be the appropriate rate to use if the weeds are small and actively growing.   Product Name Chemical Name Product Rate# lb a.i./A Traditional Herbicides    AgriStar 2,4-D LV6 2,4-D LV6 3 pt/A 2.25 Cimarron Max† metsulfuron + 2,4-D + dicamba 0.5 oz/A + 2 pt/A 0.019 + 0.97 Fuego triasulfuron + dicamba 1:8 0.028 + 0.4 Grazon P+D picloram + 2,4-D amine 3 pt/A 0.95 Reclaim clopyralid 2 pt/A 0.75 Tordon 22K picloram 2 pt/A 0.5 Weedmaster dicamba + 2,4-D amine 3 pt/A 1.45     New Herbicides    Envoke‡ trifloxysulfuron 0.5 oz/A 0.019 PastureGard§ triclopyr + fluroxypyr 3 pt/A 0.75 Plateau imazapic 6-12 oz/A 0.09-0.18 LAF004§ picloram + fluroxypyr 2 pt/A 0.34 Redeem R&P triclopyr + clopyralid 3 pt/A 1.125 Remedy¶ triclopyr 3 pt/A 1.5 Starane fluroxypyr 2 pt/A 0.375 http://forageresearch.tamu.edu Forage Research in Texas 2003. CPR-5267   Results and Discussion  In both 2001 and 2002, 2,4-D LV6, Weedmaster, Fuego, and Reclaim did not effect the DM yield of ‘Coastal’ bermudagrass in any harvest or total yield (Table 2 and 3), and Cimarron Max did not reduce the yield of Coastal bermudagrass in any harvest during the 2002 growing season (the only year it was tested). In 2001 (low rainfall year), DM yield of Coastal bermudagrass in the first harvest was reduced 54% by Envoke, and 31% by Grazon P+D, (Table 2), but not in the first harvest of 2002 (normal year) (Table 3) or total yield in either year.  In both 2001 and 2002, DM yield of Coastal bermudagrass in the first harvest was reduced 38% by Remedy, 47% by Redeem R&P, 38% by Pasturegard, and 49% by LAF004, but the total yield was not reduced in either year.     Table 2. Herbicide tolerance based on yield of established Coastal bermudagrass to various herbicides in 2001.   Harvest 1 Harvest 2 Harvest 3 Total  05-23-01 07-05-01 08-15-01  Treatment – April 19, 2001 Lb/A 2 pt Reclaim 2029 1989 3268 7285 No herbicide 1959 1647 3371 6976 Fuego (1 container/8 Ac) 1786 1863 3320 6969 3 pt 2,4-D LV6 1856 1704 3305 6865 3 pt Grazon P+D 1358 1918 3373 6649 2 pt Remedy 1234 1739 3547 6520 3 pt Weedmaster 1710 1552 3023 6286 2 pt LAF004 (experimental) 983 1524 3360 5867 3 pt/A PastureGard (experimental) 1216 1581 3063 5860 2 pt Tordon 22K 666 2202 2286 5754 4 pt Redeem 1110 1784 2796 5691 2 pt Starane (experimental) 1460 1626 2467 5553 0.5 oz Envoke (experimental) 897 1261 3098 5256 9 oz Plateau 94 1227 2092 3438 6 oz Plateau-dormant† (03-19-01) 520 1379 1516 3415 6 oz Plateau 59 1038 1960 3057 9 oz Plateau-dormant (03-19-01) 246 1252 720 2193 12 oz Plateau-dormant (03-19-01) 109 881 677 1667 LSD within each harvest 591 562 711 1432     http://forageresearch.tamu.edu Forage Research in Texas 2003. CPR-5267 Table 3. Herbicide Tolerance based on yield of established Coastal bermudagrass to various herbicides in 2002.                            In 2001 and 2002, the DM yield of Coastal bermudagrass in the first harvest was reduced 63% by Tordon 22K, and 37% by Starane, and the total harvest yield were reduced by 21% with Tordon 22K, and 23% with Starane, averaged across years (Table 2 and 3). Actively growing applications of 6, 9, 12 oz/A Plateau reduced Coastal bermudagrass DM yield in all three harvests and total yield by 46, 52, and 62%, respectively, averaged across years.  Dormant applications of 9 oz/A Plateau reduced DM yield in all three harvests in 2001 and the first two harvests of 2002, which caused total DM yield to be reduced by 47%, averaged across years (Table 2 and 3). Conclusions  The herbicides in this study were relatively safe on Coastal bermudagrass, except for Tordon 22K, Starane, and Plateau, which caused reduction in total DM yield.  Tordon 22K and Starane are typically used as spot-treatments for “hard –to-control” weed or brush species; therefore their effects on pasture weed control are minimal.  Based on these results, herbicide selection for broadleaf weed control should be based on price and weed efficacy.  Plateau is the only labeled herbicide for grass and sedge control in pastures, and should only be used when there is a specific grassy-weed problem, because it reduces bermudagrass production.   Harvest 1 Harvest 2 Harvest 3 Harvest 4 Total  05-15-02 06-14-02 07-15-02 09-10-02  Treatment – April 19, 2002 Lb/A 3 pt 2,4-D LV6 3031 3722 4279 3078 14112 No herbicide 2402 3942 4243 2858 13446 Cimarron Max Rate II 3078 3234 4212 2927 13411 Fuego (1 container/8 Ac) 2436 3581 4129 2569 12716 3 pt Grazon P+D 1852 3580 4140 2819 12393 0.5 oz Envoke (experimental) 1976 3345 4049 2857 12227 2 pt Reclaim 1805 3430 4107 2435 11778 9 oz Plateau  (applied 02-15-02) 1240 2717 3917 3655 11530 3 pt Weedmaster 2024 3075 3901 2454 11454 2 pt Remedy 1479 3193 3992 2587 11252 3 pt Redeem 1202 3613 3825 2219 10860 3 pt/A PastureGard (experimental) 1511 3306 3816 2346 10978 2 pt LAF004 (experimental) 1282 3365 3954 2000 10600 2 pt Tordon 22K 960 3183 3964 2396 10504 2 pt Starane  (experimental) 1218 2793 3788 2048 9848 6 oz Plateau 376 2399 3669 2557 9002 9 oz Plateau 321 1835 3474 2567 8198 12 oz Plateau 281 1003 2785 2248 6317 LSD within each harvest 938 939 552 N.S. 2460 http://forageresearch.tamu.edu Forage Research in Texas 2003. CPR-5267  Literature Cited 1) Bovey, R.W., R.E. Meyer, and E.C. Holt. 1974. Tolerance of bermudagrass to herbicides. J. Range Manage. 27:293-296. 2) Brooks, J.R., P.A. Baumann, and G.D. Morgan. 1996. Phytotoxicity of postemergence herbicides to Tifton 85, Jiggs, and Coastal bermudagrass (Cynodon dactylon). Proc. So. Weed Sci. Soc. 49:59. 3) Eichhorn, M.M. and J.W. Wells. 1995. Effect of post-emergence weed control herbicides on Coastal bermudagrass. Proc. So. Weed Sci. Soc. 48:90. 

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Effect of various herbicides on yield of established 'Coastal' bermudagrass

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Effect of various herbicides on yield of established 'Coastal' bermudagrass

Abstract

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Full text

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Texas A&M University

Texas A&amp;M Repository

Texas A&M Repository