As southern rust continues to worsen in parts of Nebraska, University of Nebraska-Lincoln Extension Plant Pathologist Tamra Jackson-Ziems is advising on how to handle the various crop diseases impacting producers.
In southern counties, southern rust is becoming more widespread and severe. During the past week, the disease has been confirmed in several northern Nebraska counties. Jackson-Ziems says producers and agronomists must continue to scout for southern rust immediately and repeatedly. Gaining a better understanding of where the disease has developed can help producers make more informed decisions about whether or not to apply fungicides.
Gray leaf spot has also been an issue in many areas. However, foliar fungicides can help manage the disease. Producers should keep in mind that infection may have already occurred one-to-two leaves above the highest leaf with visible lesions.
Across most of the state, bacterial leaf streak has been confirmed and is more severe than it has been in past years. In confirmed cases, lesions may appear bright yellow when backlit. Foliar fungicides are typically ineffective at controlling the bacteria that causes this crop disease.
Finally, frogeye leaf spot has begun to sprout up in some fields, which soybean producers need to be aware of this season. Foliar fungicides can occasionally be effective at managing the disease, but resistance has been confirmed in some Nebraska locations.
Samples should be submitted in plastic bags to the UNL Plant and Pest Diagnostic Clinic if producers want more insight into what may be affecting their particular crops.