To minimize the effect of sclerotinia, mustard should not be seeded in the same field more than one year in four. Fields should be free of wild mustard and volunteer oilseed crops. Mustard fits well in a rotation with cereal grains. Mustard seed requires 90-95 days to mature and the seedlings are quite tolerant of frost. To maximize yields and avoid damage by an early fall frost, yellow mustard should be seeded by the end of May, while brown and oriental mustard can be seeded up to the first week of June.
Yellow mustard is resistant to shattering and therefore can be straight-combined.
Brown and oriental mustards are less resistant to shattering and are usually swathed. Brown mustard should be swathed when 60 percent of the seeds are reddish-brown. Oriental mustard should be swathed when 75 percent of the seeds are yellow. Mustard is ready to combine when seed moisture reaches 12-13 percent or less. For long-term storage, mustard seed should be at 9 percent moisture.