Flax does not compete well against weeds and is usually grown with pesticides as the major weed control tool. Because of its value as a health food and because of consumer demand for flax produced with little or no chemicals, research is being conducted to find new methods for farmers to produce flax to meet this demand.

Organic producers will typically delay seeding of their crops so that weeds are killed before planting the crop. The goal of the present project is to enhance this period of weed growth prior to seeding with the hopes that there will be less weed emergence or weed competition after the crop has been planted.

Weed growth was stimulated using a rotary harrow in either the fall or spring (or both) and by applying nitrogen fertilizer early in the spring. Glyphosate was used to kill the weeds prior to seeding with no other pesticides used.

Rotary harrowing significantly increased weed emergence while early applied nitrogen did not appear to have an effect. Early seeded check plots had significantly higher levels of post seeding weed numbers and weed biomass indicating that delayed seeding improved weed control.

In the delay-seeded plots, post seeding weed emergence levels and weed biomass were similar among the rotary harrow and early nitrogen treatments. This indicates that the treatments did not speed up the weed emergence window which would have had the effect of planting even later than they were. Because more weeds emerged over the growing season this may be an effective way of depleting a seed bank in which case these treatments may have a greater effect.