Herbicide resistance is 'wicked' in nature; therefore, results of the many educational efforts to encourage diversification of weed control practices in the United States have been mixed. It is clear that we do not sufficiently understand the totality of the grassroots obstacles, concerns, challenges, and specific solutions needed for varied crop production systems. Weed management issues and solutions vary with such variables as management styles, regions, cropping systems, and available or affordable technologies. Therefore, to help the weed science community better understand the needs and ideas of those directly dealing with herbicide resistance, seven half-day regional listening sessions were held across the United States between December 2016 and April 2017 with groups of diverse stakeholders on the issues and potential solutions for herbicide resistance management. The major goals of the sessions were to gain an understanding of stakeholders and their goals and concerns related to herbicide resistance management, to become familiar with regional differences, and to identify decision maker needs to address herbicide resistance. The messages shared by listening-session participants could be summarized by six themes: we need new herbicides; there is no need for more regulation; there is a need for more education, especially for others who were not present; diversity is hard; the agricultural economy makes it difficult to make changes; and we are aware of herbicide resistance but are managing it. The authors concluded that more work is needed to bring a community-wide, interdisciplinary approach to understanding the complexity of managing weeds within the context of the whole farm operation and for communicating the need to address herbicide resistance. Weed Technology cambridge.org/wet Education/Extension Cite this article: Schroeder J

To test if fungicide applied to hail-injured corn improves yield and reduces disease, we simulated hail at VT and R2 growth stages for three years at three Iowa locations for a total of five site years. Hail damage was simulated using a string trimmer or an ice-propelling machine and non-hail controls were included. Estimated defoliation ranged from 5 to 51%, along with ear and stalk injury. After hail events, Headline AMP fungicide (pyraclostrobin + metconazole) was applied at an “immediate” or “deferred” timing (averaging 3 and 8 days afterwards, respectively). A non-fungicide treated control was included in hailed and non-hail control plots. Hail injury reduced fungal foliar disease compared to plants without hail injury, although overall disease severity was low during this study. Hail events at VT or R2 decreased yield compared to control plots (P = 0.1). Fungicide application did not provide yield-increasing plant health benefits after VT and R2 hail, at either “immediate” or “deferred” timing. While yield differences were not statistically significant, a cost/benefit analysis showed deferred fungicide application after VT hail, and immediate and deferred applications after VT for non-hail plots did provide positive economic returns. Results will help inform decisions about fungicide use in hail-damaged corn when foliar diseases are not present at high levels. Accepted for publication 7 January 2016. Published 13 January 2016.

Effective outreach is critical to achieving success in managing herbicide-resistant weeds. Interdisciplinary collaboration is needed to adapt information delivery and to engage communities to address the herbicide-resistance problem. Weed scientists must partner with the production community to adapt herbicide-resistance practices for local needs, to work collaboratively with state and regional stakeholders to create effective resistance-management practices, and to provide an overarching national message as to the causes of, and solutions to, resistance.

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Nearly 400 herbicide‐resistant weed biotypes due to one or several modes of action have been documented worldwide. Certified crop advisors (CCAs) were surveyed in December 2012 about the attitudes of clients toward resistant weeds and management. About 10% of total U.S. (∼1000 North Central, 60 Northeast, 165 West, and 257 South and Southeast regions) and Canadian (232) CCAs responded to the survey. Results were grouped by country, U.S. region, and job classification, with differences identified using χ2 analysis. Twenty‐three percent of the South and Southeast regions CCAs identified the weed resistance level in their territory as “heavy,” whereas 5.5% identified the level as “epidemic,” compared with 0 in these categories for Canadian CCAs and CCAs in the U.S. Northeast and West regions. About 1% of CCAs in sales identified weed resistance as “epidemic,” compared with 5.6% of agriculture manufacturer representatives. Resistance management tactics listed frequently included multiple modes of action (20%), herbicide or crop rotation (16% each), and preemergence or residual herbicide application (14%), whereas integrated pest management was listed <2% of the time. In the South and Southeast regions, about 50% of the respondents thought that producers would modify current production practices “…only if the resistant weed were present in their fields,” whereas 37 and 31% of the North Central and Northeast/West regions, respectively, chose this answer. The cost of resistance implementation was seen as a primary barrier to implementation by 24% of the Northeast/West, North Central, and Canadian respondents. These findings suggest that solutions for weed resistance must be effective, easily implemented, and cost conscious to maximize acceptance and implementation by farmers.