DEKALB® Hybrid Corn Response to Corn Fungicides – South

February 10, 2026

Click on a tab below to see data collected each year for this study

TRIAL OBJECTIVE

  • Bayer Crop Science offers a portfolio of corn fungicide products for the South.
  • This trial was an evaluation of Delaro® 325 SC fungicide as a candidate product for managing southern corn diseases.
  • In many cases, timely fungicide application can aid in reducing disease pressure and allow for increases in harvested grain yield.

RESEARCH SITE DETAILS

Testing Conditions for DEKALB Seed and Absolute Maxx and Delaro 350 SC Corn Fungicide Applications.

Table 1. DEKALB® brand corn products planted and their traits and relative maturities.

Table shows three DEKALB Brand Seed Hybrids tested with their Bayer Corn Trait, and relative maturity.]
  • All field work, tillage, and herbicides were per local standards.
  • Fungicide application treatment -
    • Date: 5/17/2025 via drone at 3 gal/acre spray volume
    • UTC – Untreated Check
    • Delaro® 325 SC fungicide at 8 oz/acre + nonionic surfactant (NIS) at 1/8 percent volume to volume (vol/vol) ratio.
    • Absolute® Maxx fungicide at 6 oz + NIS 1/8% vol/vol
  • Trial used non-replicated strip plots.
    • Plot size: 12 rows, each 1,000 feet long; approximately 1 acre per experimental unit
    • Data collected as follows –
      • Commercial combine machine harvested yields were corrected to 15.5% moisture for reporting.
  • This site would be characterized as a low to moderate disease environment with Southern rust (Puccinia polysora) being the primary disease organism present in the study. Disease pressure was noticed relatively late in the season.

UNDERSTANDING THE RESULTS

Corn yield application response graph for 3 different hybrids of DEKALB seed with no treatment, Delaro corn fungicide, or Absolute Maxx fungicide treatments.
Figure 1. Yield response of three DEKALB® brand corn products to fungicide applications in Scott, MS.

Average corn yield application response graph for 3 different hybrids of DEKALB seed with no treatment, Delaro fungicide, or Absolute Maxx corn fungicide treatments.
Figure 2. Average yield response to fungicide treatments across corn products.

  • Two out of three tested corn products responded with increased yields with the Delaro® 325 SC fungicide and Absolute® Maxx fungicide treatment when compared to the UTC (Figure 1).
  • DKC119-30 Brand did not have as high of a yield response to fungicide treatment as DKC65-99 Brand and DKC68-35 Brand (Figure 1). These results are consistent with DKC68-35 Brand having positive responses to fungicide application when disease is present in commercial settings.
  • Averaged across the three corn products in this study, a yield increase of 13 and 17 bu/acre were observed with Delaro® 325 SC fungicide and Absolute® Maxx fungicide treatments, respectively (Figure 2).

KEY LEARNINGS

  • Delaro® 325 SC fungicide and Absolute® Maxx fungicide are excellent options for disease management in Southern fields growing DKC65-99 Brand and DKC68-35 Brand.
  • Each field, farm, corn product, and agronomic case should be evaluated individually for the need for a fungicide application.
  • Please contact your Bayer Crop Protection or DEKALB® brand representative for more information.

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Disclaimer

Always read and follow pesticide label directions, insect resistance management requirements (where applicable), and grain marketing and all other stewardship practices.