Variety affects radicle emergence test results in wheat

Thirty seed lots from four spring wheat varieties produced in Finland in 2019 were RE-tested according to ISTA rules, counting the number of seeds with a 2 mm-long radicle after 48 hours in a germination test at 15°C in darkness. There were significant differences among the varieties in RE counts (p < 0.001). There were also differences within varieties in RE counts that could indicate vigour differences between the seed lots. The thousand seed weight (tsw) varied between varieties. However, tsw did not explain differences in RE counts (p = 0.10). The variety effect complicates the interpretation of RE results and our results suggest that RE results should only be used to compare seed lots within the same variety. Varieties should preferably have established RE result baselines. It would not be easy to assess new varieties until the necessary data has been generated.