North Dakota Flax Variety Trial Results for 2025 and Selection Guide

In 2025, North Dakota saw a sharp rebound in flax planting: acreage reportedly jumped from roughly 92,000 acres in 2024 to about 275,000 acres in 2025, making flax once again a major crop in the state. However, with the return to larger flax acreage, growers are facing renewed agronomic challenges. Because flax is a “poor competitor with weeds,” fields that are not extremely clean or that have delayed weed control risk yield losses from weed competition — a problem that becomes more critical as acreage expands. Harvest and handling issues also remain a concern: flax seeds and straw tend to dry unevenly, and poor threshing or drying can lead to high dockage (often 5%-10%), seed loss and reduced test weight if combines aren’t adjusted properly. Moisture at harvest — especially in late-sown or late-maturing fields — can make threshing difficult, increase seed spoilage or dockage and complicate storage. Additionally, because flax performs best with long rotations (e.g., once every three-plus years on the same land) to avoid disease and soil-borne issues, the recent surge in acreage raises concern over potential disease-pressure build-up — particularly in areas where rotation cycles tighten or where flax is sown more frequently. In short, while 2025’s expanded flax acreage in North Dakota shows renewed grower interest and demand, the combination of weed pressure, harvest/handling sensitivity, moisture risk at harvest and increased reliance on tight rotations makes agronomic management and careful field selection more critical than ever.

This selection guide summarizes flax variety performance at the various North Dakota State University Research Extension Centers. Give special attention to flax yield results of those trials nearest to your production area when evaluating varieties in these trials. Also, attempt to view yield averages of several years rather than using only one year’s data as a determining factor. In addition, consider other agronomic characteristics — such as maturity, disease tolerance, lodging score and oil percentages — if available.

The agronomic data presented are from replicated research plots using experimental designs that enable the use of statistical analysis. The least significant difference numbers beneath the columns in tables are derived from the statistical analyses. If the difference between two varieties exceeds the LSD value, it means that with 95% or 90% probability (LSD 0.05 or 0.10), the higher-yielding variety has a significant yield advantage. If the difference between two varieties is less than the LSD value, then the variety yields are considered similar.

The coefficient of variation is a measure of variability in the trial and is expressed as a percentage. Large CVs mean a large amount of variation that could not be attributed to differences in the varieties. Only compare values within the table and look for trends for the desired trait among different experimental sites and years.

Oil content and harvested seed yield were adjusted to 9% moisture. The oil content data are not intended to be compared between locations.

Variety trial data from all NDSU Research Extension Centers for all crops can be found at www.ag.ndsu.edu/varietytrials and the variety selection tool at https://vt.ag.ndsu.edu/.

Research specialists and technicians contributed to the fieldwork and data compilation. Administrative assistants contributed in entering data into the respective sections of this document. We greatly appreciate the assistance provided by everyone involved.

Presentation of data for the varieties tested does not imply approval or endorsement by the authors or agencies conducting the tests. NDSU approves the reproduction of any table in this publication only if no portion is deleted, appropriate footnotes are given, the order of the data is not rearranged and NDSU is credited for the data.