摘要：Leafy spurge is an exotic, noxious, perennial weed which is widely established in the north central United States and is an especially serious problem in the northern Great Plains (Bangsund et al. 1999). In 1997, the Agriculture Research Service and Animal Plant Health Inspection Service, U.S. Department of Agriculture, initiated a major Integrated Pest Management (IPM) research and demonstration project to develop and demonstrate ecologically based IPM strategies that can produce effective, affordable leafy spurge control. In 1998 and 1999, a survey of ranchers and public land managers was conducted to evaluate managerial, institutional, and social factors that might affect the rate and extent of implementation of various control strategies. In 2001, a second survey of the same ranchers and public land managers was conducted to (1) assess any changes in land managers' perceptions of weed problems, control alternatives, and related issues, and (2) evaluate the impact of the TEAM Leafy Spurge project on the respondent's weed control practices. The impacts of noxious weeds on grazing operations, specifically leafy spurge, are not abating, and ranchers seem more aware than ever of the severity of the problem. A slightly larger percentage of respondents in 2001 view leafy spurge as a major problem and the most serious problem for grazing operations than in 1998 and 1999. Heightened awareness among landowners may also be linked to TEAM Leafy Spurge's efforts to inform landowners of the problem and offer affordable, effective weed management techniques. While the use of biological control methods, specifically flea beetles, has grown, herbicides continue to be the control practice of choice. While slightly fewer respondents reported using herbicides in 2001 than in 1998 and 1999, the vast majority of landowners plan to continue to use herbicides. Over 50 percent of respondents are using biological control, and over 76 percent of respondents indicated flea beetles were either somewhat or very effective in controlling leafy spurge. Nearly half of the respondents had heard of TEAM Leafy Spurge, and all TEAM Leafy Spurge demonstration sites, events, and publications were favorably rated. A large majority of the respondents agreed that the program had been effective in demonstrating and communicating leafy spurge treatment and control options. Based on the results of the 2001 survey, it would appear that the program has indeed made progress in communicating the type of information landowners need to address what continues to be a significant issue for grazing operations in the Midwest.
