Walking cornfields still pays

Can you give one good reason why I should go inside a hot cornfield to scout? Can’t I scout with a drone? What could I learn from drone images in August?
The Indiana certified crop adviser panel answering this question includes Betsy Bower, agronomist for Ceres Solutions, Terre Haute; Abby Horlacher, Nickel Plate Consulting, Frankfort; Brian Mitchem, proprietary products manager for Nutrien Ag Solutions, Fort Wayne; and Dan Quinn, Purdue Extension corn specialist, West Lafayette.
Bower: First, a hot cornfield isn’t a healthy cornfield. If corn has the nutrition it needs, it will be cooler as it respires vs. outside a cornfield on a hot day. You get visual pictures in your head from walking fields that you will use your whole career. For example, picture ear placement. Is ear height consistent or inconsistent? What else are you seeing? Perhaps you’re seeing yellowing in leaves, indicating potential nitrogen deficiency, or leaf spots of late diseases. Is the lower plant canopy healthy? Are corn ears pushing out husks?
Drone scouting can provide value. Depending on the clarity of pictures, you may get a good feel for general overall field health and potential nutrient deficiencies, weedy patches and more. Better drone services can provide leaf pictures to identify diseases.
Horlacher: It is always difficult to go into a cornfield in August, but it is crucial in decision-making. Drones are an excellent way to get a second viewpoint. You can see stress you may not see walking. August drone imagery can show down crop or disease, nutrient stress or water stress.
If you’re going to walk a field, fly it first to know where to ground-truth. A drone may not pick up early signs of disease. When walking, pay attention to the ear leaf. This is the first leaf to give nutrients to the ear, and you want to protect it to maintain yield potential. Walking cornfields in August will help you make timely decisions on fungicides based on how ear leaves look and disease pressure.
Mitchem: Sure, besides exercise and weight loss, there is still much to see. Grain fill, leaf disease, insect pressure and weed emergence are valuable to evaluate.
Drones can provide vegetative index levels. To be valuable, compare vegetative index levels from points A to B to C over time. Measure improvement or decline between points in time. Some more-detailed drone programs can help in identifying leaf disease and severity.
Quinn: Walking a field is still the most accurate way to properly identify and diagnose issues in the crop, even if it is hot and miserable. However, drones are valuable scouting tools because they can identify noticeable patterns that may point to equipment issues.
If you have a drone, fly regularly, and use it as a tool to identify potential problem areas in the field. However, it is still important to approach those problem areas yourself on foot for proper diagnosis. Drone imagery likely won’t tell you which specific disease or nutrient deficiency is occurring at a specific location.