Storage of primed pelleted sugar beet seed with minimal loss of seed vigour and active ingredients*

Different seed storage methods, varying in storage temperature, moisture and/or oxygen content, were applied to commercial sugar beet seed lots from four breeding companies. After storage for 10–11 months, germination of the seed was tested in the laboratory (cold test, 10°C). In addition, the contents of active ingredients (fungicides and insecticide) were analyzed and compared with the initial contents before storage. Based on these results, a selection of the most promising storage methods was made to test plant emergence in a field experiment. This research was performed in 2015/16 and in 2016/17. In both years, two storage treatments outperformed the others: these were storage in a closed jar with the addition of moisture absorber (i.e. silica gel) at room temperature and storage at –18°C in a closed plastic bag. Using these two storage methods, seed vigour and contents of active ingredients were comparable to those in seed that had not been stored for one year. Based on the results from this study, the advice to growers for a successful storage of residual sugar beet seed was adjusted in 2017, after including some practical guidelines and considerations.