Tailoring Irrigated Corn Systems with Seed, Weed, and Disease Management


  • Decisions about what pest management system in corn is the best can be difficult with limited information comparing weed and disease control options. 

  • The objective of this study was to evaluate yield effects of combining DEKALB® brand corn products, weed control, and disease control from Bayer compared to a competitive system.



Location Gothenburg, NE     
Soil Type  Hord silt loam   


Strip till 

Planting Date 04/30/20    
Harvest Date 10/31/20  

Potential Yield
Seeding Rate


  • This study was setup in a split-plot design with three replications. The weed and disease control systems were the whole plot, and corn products were the sub-plot.
  • The Bayer corn system included three DEKALB® brand corn products paired with three Bayer pesticide application programs.
  • The competitive corn system included one competitor corn product paired with a competitive pesticide application program. 
  • Table 1 contains details of the weed and disease control products used in the study, as well as the application timing when the products were applied.
  • A total of 10 inches of sprinkler-irrigation was applied in addition to the 12 inches of rain received during the growing season.
  • Fertility application included:
    • 70 lb phosphorus/acre, 15 lb sulfur (S)/acre, and 27.5 lb nitrogen (N)/acre banded with strip till on 4/26/20,
    • 100 lb N/acre applied with a streamer bar on 4/28/20, and 
    • 15 lb S/acre and 90 lb N/acre Y-drop applied with 360 Y-DROP® applicators on 6/26/20. 
  • Average yield of each corn system was calculated from shelled corn weight, moisture, and test weight.


image Table 1. Treatment descriptions including applications and timings.


image Table 2: Treatment average yield results.
image Figure 1. Average yield response by corn system.
  • There were no significant yield differences between systems; however, the Bayer systems (Systems 1, 2, and 3) produced a higher average yield than the competitive system in the trial (Figure 1).

  • The highest average yield in this trial was from Corn System 1, which included two applications of Delaro® 325 SC fungicide applied at V5 and R1 growth stages.

  • Corn System 3 included a Delaro 325 SC fungicide application at VT growth stage. This system had slightly lower average yields than Corn System 1.

  • Corn System 2 was treated with Delaro 325 SC fungicide plus Corvus® herbicide at the VT growth stage. This system had the lowest average yield of the Bayer systems.



  • Evaluating complete systems of corn products, herbicides, and disease management tools can be difficult because there are a limited number of system combinations that can be addressed in a given trial.

  • The four systems researched here are all viable systems currently used in irrigated corn production.

  • There may be some value in multiple fungicide applications, as observed in Corn System 1. 

  • Corn System 3 provided a good combination of corn, herbicide, and fungicide products that produced high average yields for this trial.

  • In summary, farmers should work with their local DEKALB® brand team member to identify which corn product, weed control option, and disease control option provides the best opportunity for success in a given field.  

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