Delaro® 325 SC Fungicide Applications on Corn


  • Fungicide applications are an in-season management decision that can provide value but deciding how often to apply a fungicide can be complicated. 

  • The objective of this trial was to look at the impact of single or multiple Delaro® 325 SC fungicide applications across several corn products.



Location Gothenburg, NE     
Soil Type  Hord silt loam   


Strip tillage  

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

Potential Yield
Seeding Rate


  • Experimental design was a split-plot with four replications per treatment. Fungicide application treatments correspond to the entire plot and the corn germplasm was the sub-plot   Three corn products were paired with two Delaro® 325 SC fungicide application programs and one non-treated check (Table 1).
  • Corn was sprinkler irrigated with a total of 10 inches of irrigation applied in addition to 12 inches of rain received during the growing season.
  • It was a relatively dry end to the growing season and minimal fungal disease development was found in the trial.
  • Fertility applied included 
    • 70 lb phosphorus (P)/acre, 15 lb sulfur (S)/acre, and 27.5 lb nitrogen (N)/acre band applied with strip till on 4/26/20, 
    • 100 lb N/acre applied by stream bar on 4/28/20, and 
    • 15 lb S/acre and 90 lb N/acre applied with 360 Y-DROP® applicators on 6/26/20. 
  • Weed control consisted of a pre-emergence application of 
    • 3.0 oz/acre Balance® Flexx herbicide, 2.0 pt/acre Harness® brand herbicide, 1 qt/acre Atrazine 4L herbicide, and 1 qt/acre Roundup PowerMAX® herbicide on 5/1/20,
    • Followed by a post-emergence application of 3.0 oz/acre Laudis® herbicide, 3 pt/acre Warrant® herbicide, and 24 oz/acre Moxy® 2E herbicide on 6/10/2020.
  • Greensnap, shelled corn weight, and harvest moisture were collected at harvest as a measure of product and fungicide application performance.

image Table 1. Treatment information including corn product and Delaro® 325 SC fungicide application rates and timing.


image Table 2. Trial treatments and resulting average yield (bu/acre) and percent greensnap.
  • Analysis showed that one of the corn products had a different greensnap response to Delaro® 325 SC fungicide treatment as detailed in Table 2.

  • The 109-RM corn product had a lower percent greensnap with Delaro® 325 SC fungicide applied at the V5+VT growth stage.

  • Analysis showed the 109-RM corn product had a positive response to fungicide application with Delaro® 325 SC by exhibiting reduced greensnap (Table 2) compared to non-treated control treatment. 

image Figure 1. Typical evidence of greensnap at the end of the season. Damage originated from high winds during a storm in mid-July 2020. Most snap occured at or one node above the main ear.
image Figure 2. Average corn yield response to Delaro® 325 SC fungicide program.
  • Overall, average yield was increased in this irrigated trial with the Delaro® 325 SC fungicide application at VT compared to non-treated control.  

  • The average yield of corn with Delaro® 325 SC fungicide program applied at V5+VT growth stages was significantly higher than the non-treated check plots. 

  • Greensnap mostly occurred in the late vegetative growth stage around V15 to V16 with a severe thunderstorm in the early hours of July 10, 2020. 


  • In this specific field trial, the VT fungicide application complemented with early fungicide application (V5) increased yield by 11 bu/acre across all corn products in a low disease environment.  

  • A fungicide application can improve plant health and potentially reduce yield loss. 

  • Farmers should work with their local Bayer sales team member to decide if a fungicide application of Delaro® 325 SC could be beneficial to their corn production acres. 

This browser is no longer supported. Please switch to a supported browser: Chrome, Edge, Firefox, Safari.