Progress 10/01/06 to 09/30/12
Outputs
OUTPUTS: This project has centered on weed management in pastures and other non-crop sites. We have developed new recommendations and technology for controlling troublesome weeds such as lantana, smutgrass, saw palmetto, blackberry, and dogfennel. These projects have produced 8 refereed publication that have been accepted into the scientific literature, 4 graduate students (2 PhD and 2 MS) students have completed degrees, 19 popular press articles have been published in trade magazines, and over 20 newsletter articles were written. PARTICIPANTS: As stated previously, 4 graduate students have been trained as part of this project: B. Fast, B. Wilder, N. Rana, and S. Chaurhari. The first three have taken positions with Dow, IFAS extension, and Monsanto, respectively. The fourth is currently a PhD candidate at North Carolina State University. TARGET AUDIENCES: Ranchers, land managers for water management districts, and IFAS extension. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Hexazinone has been, and continues to be, the only herbicide registered for smutgrass control. Though effective, it can cost up to $25/A, control generally only lasts 2-3 years, and weed control failures can occur. Through several long-term trials, it was discovered that spraying hexazinone at half rates for two consecutive years provides the same level of control as the full rate in one year. However, the likelihood of failure from repeated applications is much less than from the single. Additionally, separating the applications is allowing us to achieve control for greater than than 2-3 as we commonly see with the single application. This simple technique allows ranchers to reduce their risk of herbicide failure and achieve improved herbicide performance.
Publications
- Chaudhari, S.*, B. A. Sellers, S. V. Rockwood, J. A. Ferrell, G. E. MacDonald, and K. E. Kenworthy. 2012. Non-chemical methods for paragrass (Urochloa mutica) control. Inv. Plant Manage. 5:20-26
- Chaudhari, S.*, B. A. Sellers, S. V. Rockwood, J. A. Ferrell, G. E. MacDonald, and K. E. Kenworthy. 2012. Integrating chemical and cultural practices to control para grass (Urochloa mutica). J. Aquat. Plant. Manage. 50:39-45
- Wilder, B.*, B. Sellers, J. Ferrell, and G. MacDonald. 2011. Response of smutgrass varieties to varying rates of hexazinone. Online. Forage and Grazinglands doi:10.1094/FG-2011-0222-02-RS
- Fast, B. J.*, J. Ferrell, B. Sellers, and W. Kline. 2011. Controlling saw palmetto (Serenoa repens) with individual plant and broadcast herbicide treatments. Online. Forage and Grazinglands doi:10.1094/FG-2011-0829-01-RS
- Ferrell, J.A., B.A. Sellers, G.E. MacDonald, and W.N. Kline. 2009. Influence of herbicide and application timing on blackberry control. Weed Technol. 23:531-534.
- Ferrell, J., B. Sellers, and E. Jennings. 2012. Herbicidal control of largeleaf lantana (Lantana camara). Weed Technol. 26:554-558
- Rana, N.*, B. Sellers, J. Ferrell, and G. MacDonald. 2012. Impact of soil pH on bahiagrass competition with giant smutgrass (Sporobolus indicus var. pyramidalis) and small smutgrass (Sporobolus indicus var. indicus). Weed Sci. 61:109-116.
- Rana, N.*, B. Wilder*, B. Sellers, J. Ferrell, and G. MacDonald. 2012. Effects of environmental factors on seed germination and emergence of smutgrass varieties. Weed Sci. 60:558-563.
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Progress 10/01/10 to 09/30/11
Outputs
OUTPUTS: We have determined the most effective means of controlling bracken fern and Lantana camara. Both of these weeds are common in pastures and are poisonous to grazing livestock. These data have been disseminated in written form as well as in presentations given to local clientele groups and international audiences. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Local producer, county extension agents, international cattle producers. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Prior to 2011, there were no recommendations for control and management of bracken fern or lantana in grazed pastures. After numerous trials in several counties throughout Florida, it was determined that metsulfuron or chlorsulfuron were the most effective herbicides for bracken fern control. All other herbicides (triclopyr, fluroxypyr, aminocyclopyrachlor, aminopryalid) were ineffective and provided less than 30% control at 1 year after treatment. Contrarily, the ALS-inhibitors mentioned above provided almost 90% control. Based on this fact, we now have an effective herbicide recommendation for both bahiagrass and bermudagrass pastures. Lantana has proved to be a difficult to manage weed in Florida pastures. Previous research found that two applications (fall followed by spring) of fluroxypyr + aminopyralid would provide 90% control of lantana. However, the two application scheme and the fact that this treatment would cost approximately $100/A makes this strategy unlikely. However, in 2011 we discovered that aminocyclopyrachlor at 3 oz ai/A, applied once in the fall, would provide in excess of 90% control. The use of a single herbicide, and only one application, will significantly lower the cost of lantana control and make it a much more likely endeavor.
Publications
- Ferrell, J., B. Sellers, and E. Jennings. 2011. Control of Lantana camara with herbicides. Weed Technol. In Press.
- J. Ferrell, B. Sellers, and E. Jennings. 2012. Control of Lantana camara in pastures. http://edis.ifas.ufl.edu/ag368
- Ferrell, J., B. Sellers, and T. Wilson. 2011. Bracken fern control in pastures. http://edis.ifas.ufl.edu/ag366
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Progress 10/01/09 to 09/30/10
Outputs
OUTPUTS: Approximately 2000 posters titled, "Poisonous plants of Florida pastures" were developed and disseminated via county agents. This poster was also converted into a presentation that has been posted on the web along with streaming video of the presentation. We have also worked extensively with the herbicides aminopyralid and aminocyclopyrachlor in both pastures and rights-of-ways. The information gathered from these experiments have been used to develop extension presentations. These presentations have been provided to over 1000 herbicide applicators. PARTICIPANTS: Mike Durham. Graduate Student and staff biologist. Two full-day training sessions, targeted toward County Agents, were conducted: one at Marianna, FL and the other at Ona, FL. The topics for discussion were centered around improving safety and effectiveness of a weed control operation. TARGET AUDIENCES: County agents, farmers, professional herbicide applicators. The principle way of extending this information is through workshops. When targeting farmers or county agents, these training events usually take place within a particular county and group size ranges from 15 to 40 individuals. This allows opportunity for question and answer as well as a less formal training experience. For professional herbicide applicators, large group teaching events are more common. These are usually in the form of "short courses" or other events where multiple speakers from various locations around the region come to participate. Attendance of short courses usually ranged from 250 to 500. PROJECT MODIFICATIONS: None to report.
Impacts
Land managers are always attempting to economically improve their weed control strategy with the additional of new herbicides. One of their products of interest for brush control is aminopyralid. After several years of research, we have concluded that aminopyralid is not a highly effective herbicide for woody brush. This herbicide was found to be effective on legume species, but this is a small fraction of the troublesome species that managers wish to control. The impact of this research will likely be in the area of economics and overall weed control efficacy. If one herbicide is added to the program, another herbicide is often removed so economic stasis is maintained. Knowing that aminopyralid is less effective will prohibit beneficial herbicides from being removed. This will likely improve overall weed control without additional cost.
Publications
- Wilder, B.*, B. Sellers, J. Ferrell, and G. MacDonald. 2010. Response of smutgrass varieties to varying rates of hexazinone. Forage and grazing lands. In press.
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Progress 10/01/08 to 09/30/09
Outputs
OUTPUTS: The new herbicide, aminocyclopyrachlor (ACP), has been tested for control of weeds in pastures and rights-of-ways. It was observed to provide excellent control Bidens alba, at levels as good or better than aminopyralid. Other projects are underway to better understand bahiagrass and common bermudagrass injury associated with ACP applicaiton. Other experiments were conducted to determine the efficacy of aminopyralid on woody brush control. It was observed that aminopyralid is of limited effectiveness on non-legumeness species such as oak, sweet gum, and maple. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Utility companies, university extension personnel, departments of transportation. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Aminocyclopyrachlor (ACP) was found to be highly effective on a wide variety of annual and perennial weed species. Safety on desirable grasses was negligible in these trials. Therefore, additional research is planned to determine if plant growth regulators can be added to ACP to enhance weed control and minimize the growth potential of desirable grasses - thus reducing the necessity of regular mowing cycles. Numerous trials were completed to determine if aminopyralid, when applied with imazapyr, glyphosate, or triclopyr, would enhance control of woody brush. It was observed that broadcast applications of aminopyralid did not significantly improve brush control over imazapyr or triclopyr alone. Individual plant treatments were equally ineffective. From these data, we will not recommend the use of aminopyralid for control of mixed brush.
Publications
- No publications reported this period
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Progress 10/01/07 to 09/30/08
Outputs
OUTPUTS: Significant research has been conducted this year to determine the effectiveness of aminopyralid + triclopyr combination for control of woody species on rights-of-ways. These data will be used to train Florida department of transportation and other vegetation management personnel. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Control of woody plants generally requires more that 1 year before success or failure of experimental treatments can be evaluated. Therefore, no data are currently available to document their effectiveness.
Publications
- No publications reported this period
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Progress 10/01/06 to 09/30/07
Outputs
OUTPUTS: Blackberry control in Pastures Experiments were conducted to determine the most effective herbicide and application timing to maximize blackberry control. Triclopyr, fluroxypyr, triclopyr + fluroxypyr, and metsulfuron were each applied in spring and fall of 2007. It was observed that triclopyr and fluroxypur caused rapid leaf necrosis in both spring and fall application timings. Substantial blackberry regrowth was observed after the spring application, while applications made in the fall were more effective. Metsulfuron, conversely, was much slower acting than the previously mentioned herbicides and provided over 90% control in both the spring and the fall.
PARTICIPANTS: Brent Sellers, University of Florida, Co-PI
TARGET AUDIENCES: Forage producers in the Southeastern US.
Impacts
Metsulfuron consistently controlled blackberry regardless of application timing. Triclopyr and fluroxypyr were more effective in the fall, but still failed to reliably control blackberry. These data have resulted in a change of our blackberry control recommendations. Currently, we recommend metsulfuron when applicable and only recommend triclopyr and fluroxypyr as a fall treatment.
Publications
- No publications reported this period
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