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Improving Herbicide Stewardship and Awareness of Off-Target Impacts

Injury to cucumber plant
Figure 1: Injury to cucumber for a very long chain fatty acid (VLCFA) inhibiting herbicide.
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  • Cornell Cooperative Extension
Impact: Environmental Stewardship

Weeds compete with crops for nutrients, water, and light, leading to reduced yields and economic losses. Weeds can also indirectly impact crops by serving as alternate hosts for pests and pathogens, interfering with crop production operations, and acting as contaminants in harvested products. Farmers rely heavily on herbicides for effective weed management, but misapplication can injure crops, damage adjacent vegetation, and threaten sensitive species. Recent federal regulations related to the enforcement of the Endangered Species Act (ESA). and increasing emphasis on environmental protection highlight the need for growers to understand herbicide activity as well as the potential for off-target movement accessible, science-based training is essential to equip producers with the knowledge to apply herbicides safely while maintaining productivity. 

Cornell University developed a herbicide training course to improve grower knowledge of herbicide modes of action, plant symptomology, and off-target effects. This program was delivered at major regional grower conferences, in collaboration with Rutgers University. High-quality herbicide injury images were curated for the CALS Weed Science webpage and other CALS-based outlets, such as the USDA Hemp Multistate Project S1084. The program also included training on the EPA’s Herbicide Strategy for ESA compliance, and a nationwide webinar drew more than 200 attendees, with over 1,000 additional views online. Extension educators and collaborators shared resources through workshops, publications, and web-based platforms to ensure widespread reach among farmers, consultants, and specialists. 

Results

Over 1,000 stakeholders, including farmers, crop consultants, and extension personnel, participated in in-person trainings and webinars focused on herbicide activity and symptomology. Surveys indicated that 95 percent of participants learned new, actionable information, and 73 percent intended to implement changes in their herbicide practices. Herbicide injury photographs and symptomology notes were integrated into Cornell extension publications, improving reference materials for growers. Knowledge of the EPA’s Herbicide Strategy increased by 42 percent among webinar participants, helping prepare producers for upcoming label changes and mitigation practices. The project effectively combined research, outreach, and policy education to enhance safe herbicide use statewide. Although support for the effort ended in 2024, Dr. Sosnoskie continues to update and deliver her training materials. This project catalyzed current research projects to investigate novel weed control technologies that reduce herbicide inputs, worker exposure, and crop injury potential. 

Public Value Statement

By improving grower understanding of herbicide performance and off-target risks, Cornell University is helping farmers apply products more responsibly, reducing crop injury, protecting surrounding vegetation, and safeguarding endangered species. This work supports public health, environmental stewardship, and long-term agricultural productivity by promoting safer, science-based herbicide practices across New York and beyond. 

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