Don’t get “corn”-fused this growing season by lesions in your fields. Bacterial leaf streak and long time disease player gray leaf spot, have started making an appearance in eastern Nebraska. Bacterial leaf streak has lesions categorized with wavy margins that when back lit appear to have a slight yellow halo. When looking at gray leaf spot lesions there will be blocky edges similar to a rectangle. Remember, it is important to confirm the disease before applying treatment. Bacterial leaf streak is currently not thought to be controlled by fungicides commonly used to treat gray leaf spot. Therefore, application of a fungicide for the wrong disease may be a pricey mistake. When treating gray leaf spot, be sure to determine if you are utilizing a curative, preventive, or mixed mode of action fungicide. There are various cycles of disease throughout one growing season, so utilizing a mixed mode fungicide that contains both preventive and curative ingredients can help protect through multiple cycles of the disease. It is important to note, that curative does not mean that the fungicide will cure the plant of disease, but it will help protect against newly forming infections within the stand.
For more information check out these links to CropWatch articles!
https://cropwatch.unl.edu/bacterial-leaf-streak
https://cropwatch.unl.edu/plantdisease/corn/gray-leaf-spot
Crop Talk Megan 