| |
| Web URL(s): | http://www.swss.ws/wp-content/uploads/docs/2011 Proceedings-SWSS.pdf#page=186
Last checked: 08/05/2013
Requires: PDF Reader
Notes: Item is within a single large file |
|---|
| Publication Type:
| Report |
|---|
| Author(s): | Brosnan, J. T.;
Breeden, G. K.;
Elmore, M. T. |
|---|
| Author Affiliation: | University of Tennessee, Knoxville |
|---|
| Title: | Imidazolinone herbicides for warm-season turfgrass management |
|---|
| Section: | Weed management in turf
Other records with the "Weed management in turf" Section
|
|---|
| Meeting Info.: | San Juan, Puerto Rico: January 24-26, 2011 |
|---|
| Source: | 2011 Proceedings, Southern Weed Science Society. Vol. 64, 2011, p. 78. |
|---|
| Publishing Information: | Champaign, Illinois: Southern Weed Science Society |
|---|
| # of Pages: | 1 |
|---|
| Keywords: | TIC Keywords: Digitaria ischaemum; Growth retardation; Herbicide evaluation; Herbicide injury; Imazapic; Inflorescences; Paspalum dilatatum; Seedhead inhibition; Trinexapac-ethyl; Zoysia japonica
|
|---|
| Cultivar Names: | Zenith |
|---|
| Abstract/Contents: | "Zoysiagrass (Zoysia spp.) are commonly used on golf course fairways and roughs in warm-season climates. However, inflorescence (i.e., seedhead) production can compromise the aesthetic and functional quality of zoysiagrass stands. Research was conducted in 2010 evaluating the use of imidazolinone herbicides for zoysiagrass seedhead suppression, growth regulation, and weed control. Field research was conducted at the East Tennessee Research and Education Center (Knoxville, TN) on a mature 'Zenith' zoysiagrass (Zoysia japonica Steud.) fairway mowed at 1.5 cm. Mowing ceased after treatment application to facilitate assessments of seedhead suppression. Plots (1.5 x 3.0 m) were arranged in a randomized complete block design with three replications. Treatments included imazamox at 26, 52, and 70 g ai ha-1, imazapic at 52 g ai ha-1, and an untreated control. All treatments were applied with a methylated seed oil surfactant at 1% v/v one day before seedhead emergence on 9 April 2010. Sequential applications were made three weeks later. Treatments were applied with a CO2 powered boom sprayer calibrated to deliver 280 L/ha using four, flat-fan, nozzles at 124 kPa. Each week seedhead suppression and zoysiagrass injury were visually evaluated on a 0 (no suppression or turf injury) to 100% (complete suppression or complete kill) scale. At 6 weeks after initial treatment (WAIT) seedheads were counted in two 0.09 m2 sections of each plot. Turfgrass color was assessed visually on a 1 (brown turf) to 9 (dark green turf) from 9 to 17 WAIT as well. Greenhouse research was conducted at the University of Tennessee evaluating the efficacy of imidazolinone herbicides for zoysiagrass growth regulation. Cores (6 x 5 cm) of 'Zenith' zoysiagrass were removed from field plots, potted in a medium of peat moss (55%), perlite (25%), and vermiculite (20%), and placed in a greenhouse with an average day/night temperature of 27/15 C and peak light intensity of 743 μmol m2 s-1 1 for 3 weeks. During this acclimation time plants were clipped weekly at 2.5 cm. After treatment application, clipping ceased to facilitate assessments of growth regulation. Treatments, arranged in a randomized complete block design with three replications, included imazamox at 26, 52, and 70 g a ha-1, imazapic at 52 g ai ha-1, trinexapac-ethyl at 96 g ai ha-1, and an untreated control. Treatments were applied with a CO2 powered boom sprayer calibrated to deliver 280 L/ha using four, flat-fan, nozzles at 124 kPa. Each week zoysiagrass injury was visually evaluated on a 0 (no turf injury) to 100% (complete kill) scale. Canopy height (mm) of each pot was also measured weekly. To quantitatively assess growth regulation, at 8 weeks after treatment (WAT) all aboveground biomass was harvested from each pot, dried at 105 C for 48 hours, and weighed. Late-season field trials were conducted to evaluate weed control with imidazolinone treatments exhibiting efficacy for zoysiagrass seedhead suppression and growth regulation. Research was conducted on mature bermudagrass stands infested with multi-tiller smooth crabgrass (Digitaria ischaemum Schreb.) and dallisgrass (Paspalum dilatatum Poir.) at the East Tennessee Research and Education Center. Plots (1.5 x 3.0 m) were arranged in a randomized complete block design with three replications. Treatments included imazamox at 52 and 70 g ai ha-1, imazapic at 52, 105, and 175 g ai ha-1, and an untreated control. All treatments were applied with a nonionic surfactant at 1% v/v on 31 August 2010 with a CO2 powered boom sprayer calibrated to deliver 280 L/ha using four, flat-fan, nozzles at 124 kPa. Weed control and turf injury were visually evaluated on a 0 (no control or turf injury) to 100% (complete kill of all weeds or turf) scale. Imazamox at 52 and 70 g ai ha-1 suppressed zoysiagrass seedheads ~100% at 6 WAIT. Imazapic at 52 g ai ha-1 responded similarly. Seedhead counts supported visual assessments of seedhead suppression. No imidazolinone herbicide evaluated for seedhead suppression injured zoysiagrass >10%. Additionally, all imidazolinone treatments increased zoysiagrass color compared to the untreated control from 9 to 17 WAIT. In the greenhouse, all imazamox treatments and imazapic (52 g ai ha-1) reduced zoysiagrass canopy height greater than trinexapac-ethyl. Additionally, imazamox at 52 and 70 g ai ha-1 and imazapic reduced zoysiagrass biomass greater than trinexapacethyl as well. Rates of imazamox demonstrating efficacy for seedhead suppression and growth regulation were active against smooth crabgrass and dallisgrass; however, no imazamox treatment provided greater than 50% control of either species. Imazapic at 175 g ai ha-1 controlled both smooth crabgrass and dallisgrass >75%, but resulted in ~20% turfgrass injury. These responses suggest that imazamox can be used for 'Zenith' zoysiagrass seedhead suppression and growth regulation; however, additional research is needed to determine weed control strategies with imazamox." |
|---|
| Language: | English |
|---|
| References: | 0 |
|---|
| Note: | This item is an abstract only! |
|---|
| ASA/CSSA/SSSA Citation (Crop Science-Like - may be incomplete):
Brosnan, J. T., G. K. Breeden, and M. T. Elmore. 2011. Imidazolinone herbicides for warm-season turfgrass management. South. Weed Sci. Soc. Proc. 64:p. 78. |
| Fastlink to access this record outside TGIF: https://tic.msu.edu/tgif/flink?recno=226715 |
| If there are problems with this record, send us feedback about record 226715. |
| Choices for finding the above item: |
|---|
| Web URL(s):
http://www.swss.ws/wp-content/uploads/docs/2011 Proceedings-SWSS.pdf#page=186
Last checked: 08/05/2013
Requires: PDF Reader
Notes: Item is within a single large file |
| 
MSU catalog number: b2207931 |
| Find from within TIC:
Digitally in TIC by file name: swssp2011 |
| Request through your local library's inter-library loan service (bring or send a copy of this TGIF record) |
