Objectives
The objective of this project was to demonstrate the potential benefits of a registered seed treatment application for flax when combined with low, medium and high seeding rates and either early or late seeding dates.
Project Description
Although certain aspects of the results were unexpected, this project demonstrated that both higher seeding rates and seed treatments can improve flax establishment. While these effects were observed with both early and late seeding, such practices are more likely to beneficial when combined with early seeding into cold soils where overall emergence tends to slower and seedling survival is often lower.
Plant densities increased linearly with seeding rates and overall were substantially higher than anticipated. Both seed treatments and higher seeding rates resulted in slightly earlier maturity, but their effect was small relative to the effect of seeding date. While seed treatments did not result in higher yields under the conditions encountered, they resulted in 11% higher plant populations which could certainly be beneficial if overall plant populations had been lower. By comparison, delayed seeding resulted in an 18% increase in final plant populations as a result of the warmer soils and better moisture conditions. While delaying seeding reduced the time required for the crop to reach maturity by over 9 days, the late seeded flax still matured over 2 weeks later and, more importantly, the mean yield for early seeded flax was a dramatic 75% higher than late seeded flax. Demonstrations over the past few years at Indian Head have not found much yield difference between early versus late seeded flax, particularly when averaged over multiple years; however, early seeding has generally been recommended whenever possible. The greatest advantage to early seeding has been to allow for earlier harvest but there can be other advantages including better use of early spring moisture and earlier flowering before the weather potentially becomes too hot and dry. Early seeding has also been promoted as part of an integrated management strategy to reduce yield losses associated with pasmo, the most important disease affecting flax in Saskatchewan. With a slight yield reduction at the 75 kg/ha rate, the response to seeding rates was unexpected but likely attributable to the combined effects of much higher than expected plant populations combined with the specific environmental conditions encountered (i.e. wet weather late in the season, relatively high disease pressure).
Overall, results from this demonstration suggest that flax should be seeded early at rates of approximately 55 kg/ha to achieve early maturity and maximum yield. Seed treatments have strong potential to improve establishment (based on limited data) but how frequently they improve yield is less certain and will often depend on other factors such as early spring environmental conditions and the absolute plant densities achieved.
