New rootstocks typically may gain commercial interest based on outstanding performance in one or a few locations, and after only a few years of observation by researchers or growers. Sometimes additional evaluations and over longer duration will reveal unanticipated faults or limitations to successful use. The best information about how a rootstock will perform in graft combination with a fruiting scion cultivar is obtained by data collection and careful comparisons among numerous rootstocks in replicated field trials. The most reliable information to use in the selection of rootstocks for large-scale field plantings will be based on favorable performance by multiple replications, over multiple years, and at multiple sites.
In the table below is a descriptive list of replicated field trials established and conducted by Kim Bowman (USDA) and with links to trial results. In some cases, trials have been completed, and results are final. In most cases trials are in progress, and results will be updated as new information becomes available. Additional publications of results from particular trials are listed as references within the trial summary. While firm conclusions from the trials, and major decisions based on trials, should await multiyear trial summaries and refereed publication of trial results, shorter-term and interim summaries can be helpful as an aid in planning, and to use in comparison with results from other trials. New hybrid rootstocks which demonstrate outstanding performance in field trials are typically released by USDA for public use shortly after the completion of supporting replicated and multiyear trials.
Click on the Trial ID to see additional information.