Building Resilience and Flexibility into Midwest Organic Potato Production: Participatory Breeding and Seed Potato Production

Building Resilience and Flexibility into Midwest Organic Potato Production: Participatory Breeding and Seed Potato Production

Summary

Organic farmers in the North Central Region face a 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. We propose a collaboration between 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.

Objectives/Performance Targets

Objective 1: Evaluate the practical and economic feasibility of on-farm production of high quality seed potatoes from minitubers.

Many pathogens that may infect potato plants can be carried in the daughter tubers and will impact the productivity of the next crop. Minitubers, small tubers produced from pathogen-free tissue culture plantlets, will be planted for three popular varieties in field and hoophouse beds on organic farms. Different planting dates and spacings will be trialed for the effect on yield. In subsequent years, harvested tubers will be compared to purchased organic seed potatoes for crop health and yield. The effect on farm income of on-farm seed potato production versus purchase will be determined using partial budgets.

Objective 2: Provide training, coordination and resources for a farmer-participatory potato breeding network.

Farmers will be provided with true potato seed from crosses between varieties that performed well on organic farms in our previous trials, and trained to make their own crosses as desired. We will collaboratively generate selection guidelines for on-farm breeding line trials to address breeding goals. Tubers from selected breeding lines will be saved and replanted for comparison with standard varieties. Promising lines will be introduced into tissue culture for long term maintenance and production.

Accomplishments/Milestones

Objective 1: Evaluate the practical and economic feasibility of on-farm production of high quality seed potatoes from minitubers.

Three farms participated in on-farm trials of seed potato production, planting pathogen-free minitubers for up to five potato varieties. Participating farms were White Earth Land Recovery Project (WELRP), Callaway MN, Paradox Farm, Ashby MN, and Stoney Acres Farm, Athens WI. Growers were advised on best practice cultural methods for planting minitubers and minimizing disease spread, including shallow planting depth, consistent soil moisture, mulching and/or hilling to control weeds and encourage tuber formation, interplanting with aphid repelling plants, mineral oil sprays, and early vinekill or copper sprays if late blight threatened crops. All growers chose to plant single replicate plots at a single spacing, using the same management practices as their production potato field. At West Madison Agricultural Research Station, minitubers for 7 standard varieties were planted in our organic seed potato production field according to our best practices (composted chicken manure fertilizer, 6 inch spacing, hilled once, mulched heavily with straw, weekly sprays with JMS Organic mineral oil).

At two other farms, events made it impossible to proceed with planned trials (a fire which destroyed farm property, and persistent medical concerns, respectively). These two farms have been excellent collaborators in the past, and we will continue to work with them if possible in 2016, but will recruit other participants if necessary.

At both WELRP and LCO, single replicates of five varieties (Carola, French Fingerling, Red La Soda, Austrian Crescent, and Yukon Gold) were planted, with 80 minitubers per plot. At WELRP, usable yield ranged from 12 to 22 lb per variety, with minimal loss to tuber defects. At both Stoney Acres Farm and Paradox Farm, single replicates were planted for Carola, French Fingerling, Red La Soda, and Yukon Gold, 40 minitubers per plot. At Stoney Acres Farm, usable yield ranged from 2 to 7 lb per variety. The Yukon Gold crop at Paradox Farm failed, but other varieties yielded well (tubers are now in storage and will be weighed in spring). At West Madison ARS, yield ranged from 65 cwt/A (Yukon Gold) to 227 cwt/A (Red La Soda. Saved tubers will be replanted at each farm and at West Madison ARS in spring 2016, to assess seedlot productivity. Leaf samples from replanted seedlots will be tested to assess virus infection, and plants will be inspected to assess health.

Objective 2: Provide training, coordination and resources for a farmer-participatory potato breeding network.

True seed potatoes from crosses between varieties that had previously performed well in organic field trials were provided to 3 participating growers. At WELRP, true potato seed was planted for 5 populations derived from crosses between high-performing potato varieties. All populations yielded well, and tubers were selected from 3 populations for replanting in 2016: yellow clones from a Carola X Yukon Gold cross, red and yellow clones from a Carola x Dark Red Norland cross, and red and yellow clones from a Keuka Gold X Chieftain cross. Unfortunately the other two growers who received true potato seed populations were those who were unable to continue participation due to events described above.

Growers were also provided with kits and written instructions for crossing potatoes. Feedback from these growers and others interested in participatory potato breeding indicated that although they were interested in making their own crosses, they would find it easier to participate if provided with either true seed from crosses, or, preferably, with minitubers from plantlets derived from true seed. To respond to this preference, we planted 200 seed for each of 27 open-pollinated seed families, representing 12 female parents, and 200 seed for each of 7 crosses between varieties that did well in organic field trials and/or varieties with Potato Virus Y resistance. Seedlings were selected for vigor and early tuber production, and a single small tuber was harvested from each seedling. These tubers will be available for on-farm evaluations in 2016.

Minitubers from crosses between the following varieties were planted at the West Madison Agricultural Research Station in the organic seed potato plot: Adirondack Blue x Fenton Blue, Sweet Yellow Dumpling x Adirondack Blue, White Lady x Adirondack Blue, and Yellow Rose x Adirondack Blue. Approximately 200 minitubers were planted for each family. Total yields from these mixed lots were comparable to yields from minitubers of standard and heirloom varieties in the same plot. Yields ranged from 110-165 cwt/A. Tubers were saved to replant in 2016. Growers were also interested in mixed lots of tubers from field grown families, so these tubers will be made available to participating growers in 2016.

Impacts and Contributions/Outcomes

Many of the farmers we work with save seed potatoes from their production fields at least occasionally, and discussions have revealed that they recognize greater disease pressure and surface defects in lots planted with saved seed. Despite this, growers participating in seed potato production trials in 2015 were still reluctant to implement additional management strategies to control pests and diseases. Since many of these farmers have reported being affected in 2015 by the soft rot outbreak in seed potato production areas of New England, it is possible that some will be more interested in management specific to seed potato production. To increase awareness of the importance of seed potato health, in 2015 we published three blog posts on the project website dealing with seed potato production, selection and handling: http://labs.russell.wisc.edu/organic-seed-potato/2015/01/12/breeding-seed-potatoes-and-weeds-oh-my-on-farm-research-opportunities-in-2015/; http://labs.russell.wisc.edu/organic-seed-potato/2015/02/16/a-potato-is-a-potato-is-a-potato-right-considerations-for-ordering-seed-potatoes/; http://labs.russell.wisc.edu/organic-seed-potato/2015/03/09/handling-seed-potatoes/. We additionally provided information on potato breeding in another blog post: http://labs.russell.wisc.edu/organic-seed-potato/2015/03/23/tps-trials/.

Updates on research progress in organic seed potato production and organic breeding were presented at two field days at West Madison Agricultural Research Station, one focused on organic vegetable production and breeding, and the other focused on organic potato breeding.

There were many opportunities this winter to engage with organic farmers and other researchers in discussions about organic potato breeding and seed production. At the Organic Seed Growers Conference organize by the Organic Seed Alliance, we presented our approach to participatory potato breeding and seed potato production in a panel discussion titled “Community Plant Breeding: Engaging Stakeholders Across the Food System From Eaters to Breeders”. At the MOSES Organic Conference, we discussed priorities in organic vegetable breeding in a roundtable format with vegetable growers. Finally, at the Indigenous Farming Conference organized by the White Earth Land Recovery Project, we presented on approaches to setting up a small scale seed potato system, and approaches for early breeding line selection in organic systems. Through these events, we connected with many vegetable growers interested in breeding potatoes for organic production systems, and in organic seed potato production, and some of these growers will participate in trials in 2016.

Collaborators: