- Agronomic: potatoes
- Education and Training: demonstration, farmer to farmer, on-farm/ranch research, participatory research, workshop
- Farm Business Management: budgets/cost and returns, feasibility study
- Pest Management: cultural control, economic threshold, genetic resistance, mulching - plastic, mulching - vegetative
- Production Systems: organic agriculture
- Sustainable Communities: local and regional food systems, new business opportunities
Organic farmers in the North Central Region face a regional shortage of organically produced seed potatoes, limited availability of desired specialty varieties, and limited information on variety performance under organic management. Very little potato breeding and selection focuses on the needs of organic farmers. A decentralized system of seed potato production and breeding by a network of organic farmers would meet regional seed potato demands, enable farmers to evaluate and select outstanding lines from crosses between existing varieties, and promote interaction and learning among farmer peers. This project brings together researchers and farmers to develop goals for breeding and seed production, to trial seed potato production and breeding on organic farms, and to assess economic impacts of on-farm seed potato production.
Objective 1: Evaluate the practical and economic feasibility of on-farm production of high quality seed potatoes from minitubers and foundation class seed potatoes.
Since many pathogens of potatoes can be transmitted in tubers and will impact the productivity of the next crop, commercial seed potato production involves production and testing protocols aimed at limiting the incidence of pathogens in potato crops sold as seed potatoes. The process begins with plants propagated in sterile tissue culture, which are then grown in protected greenhouse environments to produce disease free “minitubers”. These minitubers are used for field production of foundation and certified seed potatoes. By Wisconsin law, foundation seed potatoes must meet a threshold of less than 0.5% virus incidence, and are the lowest allowable class for replanting by seed potato growers. Certified seed potatoes must meet a threshold of less than 5% virus incidence. Both grades have zero tolerance for bacterial ring rot and potato spindle tuber viroid. Other seed potato producing states have similar standards.
Changes to Wisconsin seed potato law passed in August 2017 (Wisconsin Senate Bill 23) require all farmers who plant more than 5 acres of potatoes to use only certified seed potatoes inspected by the Wisconsin Seed Potato Certification Program, or by an equivalent program in another state. In the Upper Midwest, only two organic farms produce certified seed potatoes – Vermont Valley Community Farm (WI) and since 2016, Carter Farms (ND). Since organic growers are required to source organically produced seed potatoes if possible, the limited supply of organically produced certified seed potatoes in the Upper Midwest is a problem for Wisconsin growers who plant more than 5 acres of potatoes.
Most commercial seed potato growers plant foundation seed potatoes rather than minitubers, but since organic growers require a wider variety and smaller scale of production, it is less economically feasible to produce foundation seed potatoes. Minituber production in greenhouse conditions is more scaleable, and could provide planting stock for an organic seed potato system. For this objective, participating organic growers trialed on-farm production of seed potatoes from minitubers or foundation seed potatoes in field, hoophouse and greenhouse conditions.
Objective 2: Provide training, coordination and resources for a farmer-participatory potato breeding network.
Farmers were provided with progeny from crosses between varieties that performed well on organic farms in our previous trials. Progeny were provided as true potato seed and also as tubers derived from crosses. Several participants enthusiastically participated in growing potatoes from true seed, while others found it more time-efficient to plant tubers derived from F1 crosses. To supply these tubers, we planted either transplants or minitubers from F1 seed in organic plots at West Madison Agricultural Research Station and selected tubers to share with participants. Participants were provided with guidance on starting seedlings from true potato seed, on plot design, on evaluation in-season and at harvest, and on storage of tubers for replanting.