Peppermint (cv. Black Mitcham) is a high-value crop grown for both its desirable oil composition and high yield. However, this crop is highly susceptible to Verticillium wilt, a devastating disease caused by Verticillium dahliae. While this perennial crop could traditionally be grown for five years, in recent years mint stands have begun to decline after only three years, after which oil yields declines to such an extent that the crop needs to be replanted in another field. All mint cultivars grown commercially are sterile hybrids and therefore traditional breeding for Verticillium wilt resistance has not yet been possible. Broad scale fumigants can help suppress this disease but are prohibitively expensive. Moreover, these products can negatively affect beneficial soil microbes that provide key agroecosystem services.
This project will work with mint growers to evaluate their current cultural practices and design new production systems which integrate more holistic and sustainable practices that will increase yield, reduce the need to move fields or new land, and improve soil health and their economic bottom line. We will survey and interview Midwestern mint growers, buyers and processors and gather data to elicit farmers’ decision-making processes, production costs, selling arrangements, access to markets and price premiums, and perceptions towards land availability, and technology adoptions. Farm fields will be surveyed to identify practices contributing to Verticillium wilt incidence and severity. Participatory on-farm research trials will be conducted investigating biological approaches to remediate soils currently infested with V. dahliae, cover crops and anaerobic soil disinfestation (ASD). A farmer-to-farmer education and outreach component will include field days, workshops with farmer panels and a visit of Indiana growers to Washington farms. Farmer experience will guide the development of resource publications which will be used across the state and Midwestern region. In an effort to increase farmer participation in this project, a farmer advisory committee will be formed to guide research and outreach components.
Midwestern mint growers will gain knowledge about alternative solutions for Verticillium wilt management. Knowledge gained from growers, and research and outreach efforts will translate into educational programs that are better equipped to fully support mint growers regionally with the adoption of enhanced sustainable agricultural practices.
Mint growers are running out of suitable land that is free from Verticillium wilt. Meanwhile, consumer demand for more sustainable products are increasing and mint growers are ready to embrace it. This initiative will have farreaching effects on the Midwest mint industry.
Project objectives from proposal:
The project will document current mint production practices to identify key factors contributing to Verticillium wilt and identify opportunities to integrate more sustainable practices that will ensure long-term profitability. The potential for anaerobic soil disinfestation (ASD) and cover crops to cost-effectively mediate Verticillium wilt will be determined. Mint growers will learn how to conduct on-farm research and information sharing through a farmer-tofarmer network will ensure that results are disseminated and adopted. Adoption of improved production innovations recommended from this project will lead to longer crop cycles, enhanced soil health and maintenance, improved economic viability, and better use of existing farmland.