So You Are Trying Fungicides On Corn And Soybeans, How To Evaluate If They Are Worth The Cost?
A quick trip around the county this past few days indicated that fungicide treatments are being applied to both corn and beans. I ask you think independently of your crop chemical dealer. Am I getting my monies worth for this product? For those of you that would like to “experiment” with this plant health aspect, here are a few guidelines that can help evaluate if this is truly providing any benefit.
- Know what the variety or hybrid is. For both corn and soybeans only the moderately susceptible and highly susceptible hybrids and varieties have demonstrated yield impacts in fungicide applications.
- Have more than one check strip, wider than your combine, and space them across the field. Three should be plenty but two is not enough.
- In your comparisons, do not include the parts of the field where you have weed escapes or along tree lines, these areas are going to yield less anyways, so this is false data whether it was treated or not. Make sure other variables such as soil types, soil fertility variations and pest issues are not biasing your field experiment.
- Approximately 3 weeks after applications, walk some of the strips. For corn, look at the ear leaf – what percent leaf area has got lesions in the treated vs non treated. Is gray leaf spot, anthracnose, or northern leaf blight present? For soybeans – look at the upper canopy for frogeye or downy mildew and on the lower canopy look at how much brown spot is present.
- Take averages. When you do harvest your fields, take several strips, both untreated and treated. Then take the average of the untreated strips and compare that average to the treated. Fields are not uniform and with our stand issues and unevenness across many fields this year, there is going to be even more variability.
