Not Every Fungicide Can Pass This Test

Growers can put their fungicide choice to this test.

The best way to battle low commodity prices is to maximize yield. After choosing the right hybrid or variety for every field, a grower’s next step should be choosing a crop protection program to match, including a top-performing fungicide.

“If you have a favorable environment to grow corn and soybeans, you’re going to have ideal conditions for disease,” says Bond McInnes, fungicide technical manager with DuPont Crop Protection. “These crops grow well in moisture, heat and humidity and so do fungal diseases that thrive on and under dense leaf canopies and near the soil surface. Fungal pathogens including northern corn leaf blight, soybean white mold, gray leaf spot and rusts threaten plant health and yield.”

Northern Corn Leaf Blight Severity: Effect of Application Timing

Six years of data collected at multiple research plots show the value of Aproach® Prima for northern corn leaf blight control.

Aproach® Prima for Higher Corn Yields and Profitability (2009-2015)

Using a price of $3.60 per bushel for corn, seven years of trials showed Aproach® Prima provided top profitability per acre compared to another fungicide and untreated check plots.

Sclerotinia Stem Rot Control

Treatments applied at R1. Disease severity rated at R6. Disease severity index determined by rating 30 arbitrarily selected plants in each plot and scoring plants on a 0-3 scale (0 = no infection, 1 = infection on branches, 2 = infection on main stem with little effect on pod fill, 3 = infection on main stem resulting in plant death or poor pod fill).

Application Timing Matters

McInnes says high inoculum loads and cool, wet conditions favor early disease infections this season. “The earlier an infection occurs and the longer it goes untreated, the greater the potential impact on yield.”

Application timing for soybean fungicides is typically most profitable at the R2 to R3 growth stage, he adds. “Evaluate disease pressure and potential for disease before soybeans reach the R2 stage. Getting the disease controlled early prevents leaf disruption and yield loss due to poor photosynthesis.”

For corn, apply fungicide at VT to protect yield as ears are filling. In years with heavy disease pressure, an earlier application may be needed.

Choose the Right Fungicide

Fungicides are not the same. Even when you choose a fungicide with multiple active ingredients, be aware of performance differences between the available active ingredients, says McInnes. He advises looking for these product characteristics to maximize return on fungicide investment:

  • Broad-spectrum control of key fungal diseases
  • Curative, preventive, eradicant and antisporulant activity
  • Proven action against fungicide-resistant strains of frogeye leaf spot
  • Movement within the plant to protect existing leaves, stems, emerging leaves and pods
  • Residual protection that lasts 21 days
  • Enhanced foliar health and photosynthesis under a range of conditions
  • Excellent crop safety that won’t set back soybean plant growth or reduce photosynthesis

    One product that combines those best qualities is DuPont™ Aproach® Prima fungicide, which delivers excellent distribution within the plant, and long-lasting residual, preventive and curative control. Its two modes of action help manage disease resistance and combine to protect over the life of the plant.

    With a proven single active ingredient, picoxystrobin, DuPont™ Aproach® fungicide is recommended for industry-leading soybean white mold protection and for early season corn applications.

DuPont Aproach® and Aproach® Prima fungicides are not registered in all states.

Cobra® (Valent); Domark® (Isagro); Endura®, Headline® (BASF); Omega® (Ishihara Sangyo Kaisha); Proline® (Bayer); Quilt® (Syngenta).


The information provided on this website is for reference only. Always refer to the product labels for complete details and directions for use.