info@asev.org
530-753-3142
Viticulture – Professional Development for Viticulturists Session
June 18, 2026 | 4:10 pm – 5:10 pm | Location: Grand Ballroom 100B
Research Reports
Moderator:
To be announced.
Speakers:
| 4:10 pm – 4:30 pm | Influence of Trellis System on Yield and Fruit Quality of Bunch Grapes in South Mississippi Haley Williams, Mississippi State University, West Poplarville |
| 4:30 pm – 4:50 pm | Bulletins Live and Mitigation: Updates for the Wine and Grape Industry Regarding Pesticide and Antimicrobial Label Changes Megan Luke, The Pennsylvania State University, University Park |
| 4:50 pm – 5:10 pm | Optimizing Educational Resources and Outreach Programs to Mitigate Fungicide Resistance in Vineyards Malcolm Hobbs, University of California Cooperative Extension, Napa County |
Haley Williams* | Eric Stafne
Influence of Trellis System on Yield and Fruit Quality of Bunch Grapes in South Mississippi
Haley Williams* and Eric Stafne
*South MS Branch Experiment Station, Coastal Research and Extension Center, Mississippi State University, 810 Hwy 26 West, Poplarville, MS, 39470, hnw111@msstate.edu
Trellis system selection is an important pre-planting decision in vineyard establishment, influencing vine productivity and fruit composition. While high wire bilateral cordon (HWBC) systems are widely used, vertical shoot-positioning (VSP) may offer advantages for certain southern-adapted cultivars. This study evaluated the effects of HWBC and VSP trellis systems on yield and fruit quality attributes of six interspecific hybrid bunch grape cultivars (Ambulo blanc, Black Spanish, Lomanto, Mamont noir, MidSouth, and Victoria Red) grown at the Mississippi Agricultural and Forestry Experiment Station, South Mississippi Branch, in Poplarville, Mississippi. Fruit were harvested in 2024 and 2025 and measurements included yield per hectare and per vine, cluster and berry weights, clusters per vine, berries per cluster, total soluble solids (TSS), titratable acidity (TA), and juice pH. Significant cultivar × trellis interactions were observed for all yield components, while fruit quality differed significantly among cultivars. Black Spanish, Lomanto, and MidSouth produced higher yields on HWBC, with Black Spanish and Victoria Red exhibiting greater cluster weights under this system. Berry weight was higher on HWBC for Ambulo blanc, but higher on VSP for MidSouth. More clusters per vine were observed for Lomanto, Mamont noir, and MidSouth on HWBC, and Black Spanish had more berries per cluster on HWBC. Across cultivars, Black Spanish, Victoria Red, and Ambulo blanc had the highest TSS. Black Spanish had higher TA compared to all but MidSouth, while Victoria Red and Ambulo blanc had the highest juice pH. These results indicate that trellis type had no apparent effect on fruit quality, but HWBC may be better suited for maximizing yield in these cultivars.
Funding Support: This publication is a contribution of the Mississippi Agricultural and Forestry Experiment Station. This material is based upon work that is supported by the the National Institute of Food and Agriculture, Hatch project under accession number 440157. Additional funding was provided by the U.S Department of Agriculture, Agricultural Research Service, number 59-6062-6-003.
Megan Luke*
Bulletins Live and Mitigation: Updates for the Wine and Grape Industry Regarding Pesticide and Antimicrobial Label Changes
Megan Luke*
*Penn State Extension, 5240 Knowledge Parkway, Suite B, Erie, PA, 16510, mfl5873@psu.edu
Over the past several years, the Environmental Protection Agency (EPA) has been revitalizing efforts to update all pesticide labels to reflect growing concerns about human risks of pesticide exposure and environmental risks under the Endangered Species Act. In 2024, the Herbicide Strategy was finalized and in 2025, the Insecticide Strategy was released in its final iteration. The finalized Fungicide Strategy is expected by 2027. These Strategies are the first major changes to pesticide labeling since the introduction of the Worker Protection Standards. It is prudent for Extension staff, growers, and winery managers to understand what these changes entail and to familiarize themselves with the vocabulary and tools needed to demonstrate compliance with these new use requirements. The best way to demonstrate compliance is through a thorough understanding and documentation of on-farm strategies to mitigate application risks to handlers, applicators, the environment, and our communities using EPA online tools. This presentation is focused on the requirements of the new labels, including accessing and using the Bulletins Live! 2 and the Mitigation Menu websites, and provides an overview of the “points” system now in place and specific examples of products that are commonly used in grape production, which will fall under these new requirements now or in the near future. The new drift and runoff calculators and site-specific risk mapping will be covered. Tips and strategies for supporting tech-adverse populations and working with state agencies on compliance criteria will be discussed, as will new guidance on wastewater outflow for operations using antimicrobial products (e.g., wineries).
Funding Support: This research has been conducted as a literature review of EPA guidelines, tools, webinars and strategies, including interviews with compliance staff at the state level. No specific funding was provided to support these efforts.
Malcolm Hobbs* | Michelle Moyer | Monica Cooper
Optimizing Educational Resources and Outreach Programs to Mitigate Fungicide Resistance in Vineyards
Malcolm Hobbs,* Michelle Moyer, and Monica Cooper
*University of California Cooperative Extension, Napa, 1710 soscol avenue, Suite #4, Napa, CA, 94558, mbhobbs@ucanr.edu
Variable knowledge of fungicide mitigation practices among vineyard staff indicates a need for concerted educational efforts targeting all sectors of the grape industry. Addressing social-behavioral barriers to the dissemination of knowledge of pest and disease management can support the adoption of evidence-based practices. Surveys and interviews (2018 to 2025) with winegrape industry professionals in California and Washington uncovered barriers to practice adoption, utilization of knowledge resources, and educational gaps. These findings and the resulting models of industry communication networks were used to develop and evaluate novel outreach activities for pest and disease management that promote communication and collaboration skills, optimize educational resources, and engage social networks. They suggest an approach to increasing adoption of fungicide resistance mitigation by empowering key industry educators with the resources to build, sustain, and engage local peer networks that support knowledge dissemination and practice implementation; tailor educational resources to the purpose and audience; and develop interpersonal skills that facilitate communication and collaboration on industry-wide issues. Concerted efforts that approach knowledge dissemination from this framework can further the adoption of evidence-based practices for pest and disease management, while simultaneously nurturing an outreach and educational strategy that is crucial to a resilient agricultural industry.
Funding Support: American Vineyard Foundation (#2023-2746 and #2024-2746) and Specialty Crop Research Initiative Award No. 2024-51181-43184 titled “Pathogen Monitoring and Disease Management Within a Vineyard FRAMEwork” from the U.S. Department of Agriculture’s National Institute of Food and Agriculture. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and should not be construed to represent any official USDA or U.S. Government determination or policy.
