July 29, 1998

Socioeconomic Impact of Leafy Spurge Evaluated
By Steve Merritt
TEAM Leafy Spurge Technology Transfer Specialist

SIDNEY — Leafy spurge is considered a "major" problem by twice as many ranchers as any other weed species, according to the results of a recent TEAM Leafy Spurge survey.

The survey, conducted by Larry Leistritz, a professor of Agriculture Economics at North Dakota State University, and NDSU research scientists Randy Sell and Dean Bangsund, is the first of several to be conducted for TEAM Leafy Spurge (TLS), a cooperative, five-year leafy spurge research and demonstration program funded and led by the USDA-Agricultural Research Service in partnership with the USDA-Animal & Plant Health Inspection Service.

Sell said the survey is part of a project designed to evaluate the socio-economic impact of leafy spurge and help ranchers determine which tools will provide the most cost-effective leafy spurge control for their specific situations.

"We need to know how ranchers feel about leafy spurge, the control tools that are available, and why they use or don’t use those tools," Sell said. "Getting that kind of information will enable us to help TEAM Leafy Spurge’s efforts to demonstrate integrated control technologies that are effective and cost-efficient."

The four-year project also includes a survey of land managers, or "the people who make leafy spurge and other invasive weed control decisions on non-private land," Sell said. Both surveys will be repeated during the final year of the TEAM Leafy Spurge project, he said, to see if TLS research and demonstrations influenced the way landowners and land managers use leafy spurge control technologies.

While the survey, which was directed at ranchers in five counties known to have leafy spurge (Carter County, MT; Crook County, WY; Harding County, SD; and Billings and Golden Valley counties, ND), "contains a lot of interesting numbers," Bangsund said some of the most important findings can be generalized.

"It’s clear that ranchers, even those who currently do not have infestations, consider leafy spurge as a serious threat to their operations," he said. "They recognize the problem, and that’s important."

When asked to indicate which weeds were a major, minor or not a problem, Sell said respondents listed leafy spurge as a major problem twice as often (49 percent) as any other weed (25 percent for thistles and field bindweed). When asked to rank the single most important weed, an even greater percentage of respondents — 57 percent — named leafy spurge.

Sell said the survey also indicates that ranchers understand that no one tool — including herbicides — will provide effective control in every situation.

"Nearly all of the respondents have used herbicides, for example, and 100 percent plan on using herbicides in the future," he said. "Yet only one-third of the respondents ranked herbicides as a very effective control."

Herbicides, as expected, were overwhelmingly the most commonly used control tool. Biocontrol agents were the next most popular, with more than half (54 percent) of the respondents indicating that they plan on using biocontrol agents in the future. The least popular control tools were grazing with sheep and/or goats and tillage/reseeding.

TEAM Leafy Spurge coordinator Chad Prosser said information obtained through the surveys will help direct TLS outreach efforts.

"This information will help us understand how ranchers and land managers approach the leafy spurge problem," he said. "The first survey told us we don’t have to educate ranchers about the leafy spurge threat — they already understand that. But it looks like we can do more in terms of promoting Integrated Pest Management and providing information about biocontrol."

Sell, Bangsund and Prosser are looking forward to focus groups meetings which will be held in the counties that were surveyed to collect additional information.

"Sitting down and talking with the people who are most directly affected is always a great way to get more information," Prosser said. "The focus groups will help supplement information provided by the survey."

The focus groups meetings will be publicized in local newspapers in advance, Sell said, and anyone with an interest in leafy spurge control will be encouraged to attend.

Information gathered through the surveys and focus group meetings will be used to develop an economic decision-making tool, Sell said, designed to help ranchers choose the most cost-effective control tools for their situation.

"Our ultimate goal is to provide people with a computer model they can use to see what control tools will work best for them," he said. "The model will provide control recommendations specific for their situation."

To obtain a summary of the survey findings or a copy of the full survey report, contact Carol Jensen at the NDSU Department of Agriculture Economics, PO Box 5636, Fargo, N.D., 58105-5636 (phone 701-231-7441; e-mail at cjensen@ndsuext.nodak.edu).The summary and full report are also available on the WorldWideWeb at http://www.ext.nodak.edu/homepages/aedept/aemisc/publist.htm

For more information on TEAM Leafy Spurge, biocontrol of invasive weeds or Integrated Pest Management, contact Prosser at 406-433-9403 (email at cprosser@sidney.ars.usda.gov).


Survey Results: By The Numbers

• The problems: Respondents ranked livestock prices, adverse weather conditions and cost of inputs, respectively, as their three biggest problems. Noxious weeds was ranked as the next biggest problem.

• Invasive weeds: Leafy spurge was ranked as a "major" problem by 49 percent of the survey respondents. The next most commonly mentioned weeds, thistles and field bindweed, were mentioned by just 25 percent of the respondents.

• How it spreads: Respondents believe leafy spurge most commonly spreads from adjoining land, because it’s not recognized as a threat until too late, because of a lack of cost-effective control tools and because of man’s actions.

• What they’ve used & plan to use: Of the current control tools available, 97 percent had used herbicides, 54 percent biocontrol, and one-third grazing or tillage. Those numbers mirror what respondents indicated they plan on using in the future: 100 percent said herbicides, 54 percent biocontrol and 25 percent grazing or tillage.

• Herbicides: Seventy-seven percent of the respondents believe herbicides are an economical leafy spurge control tool. Reasons for not using herbicides were environmental restrictions (62 percent), acreage of infestations too large (52 percent), excessive expense (46 percent) and inaccessibility of infested land to sprayers (42 percent). Only five percent of ranchers with leafy spurge ranked herbicides as "very ineffective," while one-third ranked herbicides as "very effective."

• Biocontrols: Two-thirds of the respondents felt biocontrol is economical, but less than 20 percent rated biocontrol as "very effective." Reasons for not using biocontrol agents included "it takes too long" (48 percent); limited access to biocontrol agents (45 percent); not knowing where to collect biocontrol agents (36 percent); and not knowing how to use biocontrol agents (30 percent).

• Sheep & goats: Only 20 percent of the respondents with leafy spurge thought grazing with sheep or goats would provide very effective leafy spurge control. Reasons for not using sheep and goats were lack of proper equipment (72 percent), competition for same forage utilized by cattle (44 percent), lack of expertise (41 percent) and investment of time (40 percent).

• Tillage, etc.: Of the control tools available, respondents were overwhelming the least interested in tillage, reseeding, mowing, burning, etc. Reasons for not using these control tools were unsuitable land for tillage (85 percent), ineffectiveness (36 percent), lack of time (27 percent) and lack of proper equipment (22 percent).

General Characteristics of Poll Respondents

• The average ranch size of respondents is 6,900 acres.

• 91 percent of the respondents have cattle, with an average of 444 head.

• 28 percent of the respondents have sheep, with an average of 1,175 head.

• 80 percent of the respondents’ gross income is derived from grazing operations.

• 72 percent of the respondents use public grazing lands.

• 56 percent of the respondents have leafy spurge on their ranches.

• Of those respondents with leafy spurge, 2.5 percent of their operational acres were infested.


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