Are you positive you have Goss's wilt?
How should you interpret a positive result?
"A positive laboratory result doesn't mean the whole field has Goss's wilt, it means the sample does," Bissonnette said. "Also, a positive result doesn't always mean that the infection of that plant is severe — it means the bacterium is present."
Additionally, as with all diagnoses, consider other factors that may be contributing to the issue, Bradley said. Other leaf blights, bacterial and fungal, may be present. Consider environmental conditions such as drought, or heat. Consider nutrient deficiencies or excesses. One or more of these factors can contribute to the widespread leaf necrosis being noted in the field this season. Any or all of these factors will each contribute to yield loss if present.
A proper diagnosis and methodical analysis of the whole situation in a field will help determine if management tactics such as rotation, tillage and selection of hybrids with adequate levels of resistance may be necessary to prevent Goss's wilt from occurring in subsequent years. For more information on the U of I Plant Clinic, visit web.extension.illinois.edu/plantclinic.