One year at one site does not yield an accurate picture

MADISON, Wis. – Be extremely wary of test plots that are not replicated, or only have a “check” or “tester” hybrid every five to 10 hybrids, warns Joe Lauer, University of Wisconsin agronomist.
The best test plots are replicated (all hybrids repeated at least twice, preferably three times).
Don’t put much stock in results from one location and one year, even if the trial is well-run and reliable, Lauer said. Years differ and the results from other locations may more closely match next year.
And don’t over-emphasize results from one type of trial. Use data and observations from university trials, local demonstration plots, and then your own on-farm trials to look for consistent trends.