There is additional delay after crimping to allow desiccation before planting. - Results from S. Mirsky at USDA-ARS indicates the ideal time to roller crimp cereal rye is when it reaches ~50 to 75 percent flowering (anthers visible throughout the heads).

When should I crimp cereal rye?

Unlike conventional growers who manage cereal rye in the spring with glyphosate, organic growers who no-till or strip-till must crimp the rye. Crimping must be done at anthesis when the rye enters the reproductive stage and its stems stiffen.

Why do you crimp cereal rye?

Roller crimping forces you to allow the rye to accumulate significant amounts of biomass before termination which is a good thing for both weed suppression and retaining soil moisture.