Integrated agronomy for high yield and stable flax production in Canada

Integrating agronomic practices can be useful in increasing flax (Linum usitatissimum L.) yield under biotic or abiotic constraints. A study was conducted to determine the combined effect of seeding density, row spacing, fertilizer, and fungicide application on no-till flax yields at three locations (7 site-years) in Saskatchewan and Manitoba, Canada. The four treatments were plant density; low (190 plants m(-2)) vs. moderate (320 plants m(-2)), row spacing; narrow (20 cm) vs. wide-row (40 cm), N rate; 65 vs. 130% of soil test recommendation, and foliar fungicide; pyraclostrobin + fluxapyroxad vs. no fungicide. No individual treatment parameter significantly affected yield; however, several combinations of treatments did. The combination of moderate density, narrow row spacing, 130% N, and fungicide application showed a 23% mean yield increase across all environments compared with the lowest-yielding combination. Still, yield ranking differed across different growing environments. The overall high-yielding combination was not productive under low-yielding environments. The same high-yielding combination, but with wide row spacing and the same combination with low density provided the most stable and moderate yield across all environments tested. Considering seed cost, yield advantage, and yield stability, the best combination was low density, narrow row spacing with 130% N and fungicide application. Among all practices, the combined application of 130% N and fungicide application significantly increased crop yield by 11% under all growing conditions. In the absence of negative interactions, producers can combine these four practices to increase flax yields depending on the cost.