Smutted grain is seen only after seed heads emerge from plants that came from infected seed. Therefore, infection that takes place in one year is not seen until plants from these infected seed mature in the succeeding year. Poor Plant Color Cold, wet soils, typical of North Carolina winters, often cause plants to become yellow, or in the case of oats, yellow and red. Older leaves sometimes die and plants look unthrifty. This condition is normal and is not considered a disease.
Plants generally respond to fertilizer and warmer weather.
However, if discoloration persists after plants begin to joint, further corrective measures may be needed. Send a soil sample for nutrient analysis to determine whether fertility imbalances are the cause. If disease is suspected, take a plant and soil sample to your county Extension agent or have the agent visit your field. When a field contains weedy areas with a poor stand, root rots or seedling diseases may be the cause. If so, the seedlings will be rotted or have lesions and be generally unthrifty.