Stripe Rust ( Puccinia striiformis): Early infections of stripe rust or yellow rust have now spread into many susceptible fields of wheat aided by the cool weather. Some yellow spots in the field may be totally covered with stripe rust and will cause yield reduction. Producers who have sprayed a foliar fungicide should experience fairly good control.
Leaf Rust (Puccinia triticina): Leaf rust is also spreading across wheat fields in TN and many other states. These rust pustules are just scattered at random over the leaves and they are more reddish in color. Sometimes the two rust diseases can be found on the same leaves. This can be very destructive. Again foliar fungicide applications can reduce the severity of these diseases.
Head Scab or Fusarium Head Blight (Fusarium sp.): Head scab is also showing up in many fields. Again, the weather has been fairly good for infection of this fungus. Symptoms are very conspicuous on emerged heads after blooming. One or more spikelets or the entire head can be killed and turn prematurely bleached or white in color. Often pink or orange masses of spores can be seen on the affected heads. This disease is sometimes hard to control even with the best fungicides, but spraying must be done as the blooming stage to expect much control. Some variety carry partial resistance but none are totally resistant.
Spraying: Most wheat has finished blooming and fungicide spraying should be over by now. Most fungicide labels state that applications must stop within 30 days of harvest. Also, once disease infection has occurred, chances of good control are reduced.