Hostname: page-component-8448b6f56d-m8qmq Total loading time: 0 Render date: 2024-04-24T17:46:02.852Z Has data issue: false hasContentIssue false

Timing and Frequency of Ethofumesate plus Flurprimidol Treatments on Bermudagrass (Cynodon spp.) Suppression in Seashore Paspalum (Paspalum vaginatum)

Published online by Cambridge University Press:  20 January 2017

B. Jack Johnson*
Affiliation:
Crop and Soil Sciences, University of Georgia, Georgia Station, 1109 Experiment Street, Griffin, GA 30223-1797
Ronny R. Duncan
Affiliation:
Crop and Soil Sciences, University of Georgia, Georgia Station, 1109 Experiment Street, Griffin, GA 30223-1797
*
Corresponding author's E-mail: bjackjohnson@mindspring.com.

Abstract

Suppression of grass encroachment of one warm-season grass into another species is an important management tool. Two field studies were conducted in Georgia to determine the timing, rates, and frequency of ethofumesate plus flurprimidol applications needed to suppress three bermudagrass cultivars and determine what effects these treatments have on tolerance of three seashore paspalum cultivars during 1998 and 1999. Tank-mixes of ethofumesate and flurprimidol applied at the 1× rate (1.7 + 0.8 kg/ha) on April 1 suppressed ‘TifEagle’ bermudagrass effectively (≥ 78%) by late September. However, the suppression of ‘Tifway’ bermudagrass (≤ 39%) and ‘common’ bermudagrass (≤ 67%) was not acceptable at the same rates and timing. Ethofumesate plus flurprimidol applied at the 1× rate in April severely injured all paspalum cultivars 61 to 65% within a 2- to 6-wk period, but the cultivars recovered to an acceptable level (≤ 30%) by 10 wk. In most instances, reduced ethofumesate plus flurprimidol rates (¼× and ½×) following the 1× rate in April did not injure the paspalum cultivars as severely as did the initial 1× rate. However, bermudagrass suppression was improved from the multiple treatments. When the chemicals were applied initially at the 1× rate and followed by four timely ¼× rates, bermudagrass suppression by late September was ≥ 72% for all bermudagrass cultivars, with the exception of common bermudagrass in 1998 (52%). Maximum injury to the paspalum cultivars during 1998 and 1999 from the four repeated ¼× rates ranged from 16 to 45% for ‘Sea Isle 1’, to 33 to 37% for ‘Sea Isle 2000’, and 21 to 52% for ‘K-3’. Ethofumesate plus flurprimidol applied initially at the 1× or 2× rate on June 30 and followed by a repeated application on July 25 did not effectively suppress (≤ 70%) common bermudagrass either year or Tifway bermudagrass in 1999. However, the suppression of common bermudagrass (≥ 83%) and Tifway bermudagrass (≥ 90%) was effective when the chemicals were applied initially at the 2× rate on June 30, followed by a 2× rate on July 25 and a 1× treatment on August 14. TifEagle bermudagrass was effectively suppressed (≥ 85%) when applied initially on June 30 and July 25 at the 1× rate. Ethofumesate plus flurprimidol applied once at the 1× rate on June 30 caused ≤ 46% injury to paspalum cultivars. The injury was generally ≥ 50% when the chemicals were applied in two or more applications.

Type
Research Article
Copyright
Copyright © Weed Science Society of America 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Literature Cited

Couillard, A. A. and Wiecko, G. 1998. A saline solution: seawater as a selective herbicide. Golf Course Manag. 66 (5): 5457.Google Scholar
Cudney, D., Elmore, C., Gibeault, V., Krueger, B., and Reints, S. 1998. Controlling common bermudagrass in cool-season turf. Turf Tales Mag. 5 (1,2): 1517.Google Scholar
Duncan, R. R. 1996. The environmentally sound turfgrass of the future. USGA Green Sect. Rec. 34 (1): 911.Google Scholar
Duncan, R. R. 1997. Seashore paspalum responds to demands of stewardship. Golf Course Manag. 65 (2): 4951.Google Scholar
Duncan, R. R. 1998. Seashore paspalum herbicide management. USGA Green Sect, Rec. 36 (2): 1719.Google Scholar
Johnson, B. J. 1992. Common bermudagrass (Cynodon dactylon) suppression in Zoysia spp. with herbicides. Weed Technol. 6: 813819.Google Scholar
Johnson, B. J. and Carrow, R. N. 1989. Bermudagrass encroachment into creeping bentgrass as affected by herbicides and plant growth regulators. Crop Sci. 29: 12201227.Google Scholar
Johnson, B. J. and Carrow, R. N. 1991. Frequency of flurprimidol-herbicide treatments on bermudagrass (Cynodon spp.) encroachment into creeping bentgrass (Agrostis stolonifera). Weed Sci. 39: 221226.CrossRefGoogle Scholar
Johnson, B. J. and Carrow, R. N. 1993a. Common bermudagrass control in tall fescue with fenoxaprop. Int. Turf Soc. Res. J. 7: 303309.Google Scholar
Johnson, B. J. and Carrow, R. N. 1993b. Bermudagrass (Cynodon spp.) suppression in creeping bentgrass (Agrostis stolonifera) with herbicide-flurprimidol treatments. Weed Sci. 41: 120126.Google Scholar
Johnson, B. J. and Carrow, R. N. 1995. Influence of fenoxaprop and ethofumesate treatments on suppression of common bermudagrass (Cynodon dactylon) in tall fescue (Festuca arundinacea) turf. Weed Technol. 9: 789793.Google Scholar
Kopec, D. M. and Gilbert, J. J. 1999. Suppression of bermudagrass in perennial ryegrass turf using selective herbicides. TurfGrass Trends 8: 13.Google Scholar
McCarty, L. B. 1996. Selective control of common bermudagrass in St. Augustinegrass. Crop Sci. 36: 694698.Google Scholar
[SAS] Statistical Analysis Systems. 1982. SAS user's guide. Cary, NC: Statistical Analysis Systems Institute. 956 p.Google Scholar