As the month of April draws to a close, little if any field work has been started across Minnesota. As of this past Monday, the National Agricultural Statistics Service reported that only four percent of the oat and no spring wheat had been planted. With the immediate forecast not looking particular encouraging, it appears that most of the small grains acreage will be seeded past the optimum planting window.
The link below points to a Minnesota Crop News article that summarizes the effects of planting wheat, barley and oats past the optimum planting window:
If you are interested in more detail, you can also follow the link below to some older research on seeding rates in spring wheat.