Harvest aids did not advance maturity of non-shatter pennycress

Reliance on summer annual crops in the Upper Midwest results in fallow land from late fall through early spring, providing opportunities to integrate winter crops, such as pennycress (Thlapsi arvense L.), onto the landscape. Pennycress agronomics have primarily been studied using unimproved wild-type lines prone to seed shatter, resulting in significant yield loss if not harvested early. However, high plant and seed moisture complicates harvest and seed storage. A new breeding line with a reduced-shatter mutation made it possible to use harvest aids to reduce plant moisture without the risk of seed loss. The objectives of this study were to quantify the reduction in pennycress seed and biomass moisture after applying a harvest aid and to assess the seed yield, oil content, and crude protein of the reduced-shatter line. This study was conducted over the 2018–2019 and 2019–2020 growing seasons with ‘“IO217” pennycress in Rosemount, MN. Seed moisture decreased to a similar level by harvest maturity regardless of treatment while swathing was the most effective method of reducing biomass moisture. Natural senescence decreased pennycress moisture content to a harvestable level at the same rate as treated plants, indicating that a harvest aid is not required at this time. Seed yield was two to six times higher than in studies using unimproved pennycress lines. Challenges associated with wild-type pennycress lines, such as uneven germination and late maturation, were prevalent in this study and further genetic improvement will be necessary to ensure successful pennycress production in the Upper Midwest.