Participatory Variety Trials: Value and Methods

Organic agricultural systems represent a set of environments that are distinct from conventional systems, and frequently distinct from each other.  Done correctly, participatory variety trials can benefit breeders developing varieties for organic systems.  Distributed participatory trials help breeders identify varieties with wide adaptation and stability, and varieties with adaptation to specific environments. When breeders decide what material to release as finished cultivars, they are limited to choosing based on known performance in the locations tested. However, many varieties are never tested in organic production systems, or only in a very limited set of organic systems. For organic farms, it is a lucky coincidence when available cultivars are superior to other breeding material for their farms. By testing material on many farms, breeders can identify specific varieties that are adapted to unique environments. When breeders partner with farmers to conduct participatory trials, the producer-cooperator provides the breeder with the sort of high-quality feedback that is difficult to obtain via other avenues.  In comparison to feedback at field days, producer-cooperator feedback reflects a deeper understanding of how the crop actually functions in their system. In comparison to feedback from producers who have tried released varieties, producer-cooperator feedback gives breeders information that they can use to improve their material prior to release. Finally, on farm trials can occasionally reveal to breeders novel ways that organic producers use a crop. The way that the farmer uses the crop may lead the breeder to focus on new traits in their breeding program.   Participatory variety trials can take many forms, representing trade-offs between cost, scope, and precision. These tradeoffs must be considered when evaluating vegetable entries in organic systems. Within-field heterogeneity can often be a challenge when conducting participatory variety trials. Complete block designs can allow experimenters to collect data that are relatively precise. However, their cost may limit the number of locations where trials can be conducted. Organic systems also display large differences between locations. For this reason, more cost efficient designs, such as augmented or alpha-lattice designs, may allow researchers to evaluate varieties in more organic systems and produce results that are relevant to a wider audience. As with experimental design, data collection protocols must be developed to balance the accuracy of the results with the time and cost involved.