Kids hope it’s not true, but adults know that learning doesn’t stop once you’re out of school. Moreover, lawn care operators (LCOs) understand that a good amount of research goes in to choosing the right products for weed control on clients’ lawns.
“I did a lot of research before I came up with my program,” noted Doug Harris, owner/operator, Harris Lawn Care, Mitchellville, Iowa. “I talked to a lot of other lawn care professionals, and did a good amount of trial and error with different products.
Likewise, Craig Martin, manager/supervisor, Greener Lawn Care, Cumberland, Md., checked with several different sources before settling on his program. “We went on recommendations from different sales representatives and universities, then developed a bit of trial and error to see if we got results as good as we anticipated.”
But even though Harris and Martin both conducted similar trials, their results were quite different. Many of the lawns Harris services had been neglected for a while and were overrun with dandelions and clover. Because of this, Harris uses post-emergence herbicides as a staple in his weed control program. On the other hand, Martin reported that he uses pre-emergence products as a mainstay and reserves post-emergence products for “quick fix” situations when broadleaf weed rear their heads.
As Harris emphasized, “what I do works around here, but other people may have different ways of doing things around the country.” Indeed, not all herbicides work in every situation or on every type of turf, so research is necessary to ensure LCOs are using the right product in the right place. This is when contractors go back to the books to find their answers.
In terms of academic findings regarding herbicides, J. Bryan Unruh, extension turfgrass specialist, University of Florida, Gainesville, Fla., related that “most of the data required to label a pesticide is generated by university extension services.” As opposed to universities simply performing studies to see if herbicides do what manufacturers say they do, academic researchers actually conduct many of the tests necessary to label products in the first place.
Researchers can be knowledgeable contacts for LCOs conducting their own tests and results of trial performed by university cooperators are available on many university Web sites.
Since many pesticides are used in the agriculture initially, before moving products into the lawn care market researchers perform tests to ensure the products are useable in turfgrass settings. “Typically, we start by looking at tolerance,” Unruh said. “We will spray [the herbicide] at a number of different rates on many different species of turf to see what the effects will be.” From there, researchers generally move on to determining what spectrum of weeds is controlled by running tests on specific products in specific situations – for instance, the effects of a brand-name herbicide on purple nutsedge. Researchers then determine if the effects are the same on turf as they are in the agriculture market.
Depending on the type of tests, Unruh noted that most university trials are done in the “real world” on areas like sod farms, golf courses and home lawns. For LCOs performing their own battery of tests, the hard part is already done. Product labels outline what weeds certain herbicides will control, but from there, LCOs can test multiple crabgrass controls, for instance, to determine which works best for their situation.
Unruh suggested, “[test in] multiple locations – don’t just try one product in one location and base your results off of that. Choose three or four landscapes or lawns and see how the product works.” This practice gives the LCO a better idea of a product’s overall efficacy rather than it’s effect on just one lawn. Unruh also noted that LCOs must consider variables like weather conditions when testing certain products. In some tests at the University of Florida, he and his colleagues found that one particular herbicide worked very well after a rainstorm. By this coincidence, they discovered that, rather than being absorbed by the foliage as originally thought, the product was actually absorbed by the roots.
Also, “you’ve got to go back and compare the cost issues,” Unruh urged. “We do this with fertilizer all the time – How much green do you get for your dollar? With Herbicides, it might cost you $50 to treat an acre and that lasts 60 days, vs. a product that may cost you $45, but you only get 50-day treatment. You’ve got to compare the cost with the duration of control.”
Unruh, Harris and Martin all agreed that other LCOs, sales representatives, universities, trade magazines and the Internet are great sources of information when choosing herbicides. To get more information on products trials and results in a certain part of the country, start by contacting extension services departments at local colleges or departments of agriculture. Links to extension services in each state are listed below.
Alabama - Alabama Extension System
Alaska - University of Alaska Cooperative Extension
Arizona - Arizona Cooperative Extension
Arkansas - University of Arkansas Cooperative Extension Service
California - University of California Cooperative Extension
Colorado - Colorado State Cooperative Extension
Connecticut - Connecticut Cooperative Extension System
Delaware - Delaware Cooperative Extension
Florida - University of Florida Extension
Georgia - Georgia Cooperative Extension Service
Hawaii - University of Hawaii Cooperative Extension Service
Idaho - University of Idaho Extension
Illinois - University of Illinois Extension
Indiana - Purdue University Extension
Iowa - Iowa State University Extension
Kansas - Kansas State University Research & Extension
Kentucky - University of Kentucky Cooperative Extension Service
Louisiana - Louisiana Cooperative Extension Service
Maine - University of Maine Extension
Maryland - Maryland Cooperative Extension
Massachusetts - University of Massachusetts Extension
Michigan - Michigan State University Extension
Minnesota - Minnesota Extension Service
Mississippi - Mississippi State University Extension
Missouri - University of Missouri Extension
Montana - Montana State University Extension Service
Nebraska - University of Nebraska Cooperative Extension
Nevada - University of Nevada Cooperative Extension
New Hampshire - New Hampshire Cooperative Extension Service
New Jersey - Rutgers Cooperative Extension
New Mexico - New Mexico State University Cooperative Extension Service
New York - Cornell University Cooperative Extension Service
North Carolina - North Carolina Cooperative Extension Service
North Dakota - North Dakota State University Extension Service
Ohio - The Ohio State University Extension
Oklahoma - Oklahoma Cooperative Extension Service
Oregon - Oregon State University Extension
Pennsylvania - Penn State Cooperative Extension
Rhode Island - University of Rhode Island Cooperative Extension Service
South Carolina - Clemson University Cooperative Extension Service
South Dakota - South Dakota State University Cooperative Extension Service Tennessee - University of Tennessee Extension
Texas - Texas Agricultural Extension Service
Utah - Utah State University Extension
Vermont - University of Vermont Extension System
Virginia - Virginia Cooperative Extension
Washington - Washington State University Extension
West Virginia - West Virginia University Extension Service
Wisconsin - University of Wisconsin Extension
Wyoming - University of Wyoming Cooperative Extension Service
The author is Assistant Editor for Lawn & Landscape magazine and can be reached at lspiers@lawnandlandscape.com.