Kansas reports that they were seeing it throughout the state in late October. The bands run across the leaf veins and may be up to 1.4 inch long. Cause of color banding is due to cold injury to the seedlings soon after they emerge. The damage occurs to the tender, rapidly expanding tissues near the base of the leaves. A series of warm days with cold nights can give rise to a series of color bands separated by health appearing green tissue.
Seedlings harden rapidly and resist further damage.
Seedlings should grow out of it and it should not be a problem. The first is for preparation for the Certified Crop Advisor training exam. The other is training for Commercial Applicator certification. The workshop is being organized and conducted by the Crops Extension Specialist, Dr. John Mortvedt and the Water Quality Specialist, Regan Waskom. The second workshop is in the San Luis Valley and is for Commercial Applicator Training.