2019 Applied Research Results, Field Crop Disease and Insect Management now available

The 2019 edition of our annual report on applied research in field crop disease and insect management can be downloaded at the following link: https://uofi.box.com/v/2019PestPathogenARB


Each year, University of Illinois plant pathologists and entomologists produce a summary of the applied research we have conducted to inform disease and insect management practices in Illinois. This information provides a non-biased, third-party evaluation of control tactics such as pesticides and resistant varieties for use in corn, soybean, and wheat.

The 2019 report includes information on the following topics:

  • Surveys of insect pests and soybean cyst nematodes
  • Control evaluations for diseases of corn, soybean, and wheat (including southern rust, tar spot, fusarium head blight, and more)
  • Evaluations of Bt trait packages and soil insecticides in corn and foliar insecticides in soybean (including western corn rootworm, bean leaf beetle, dectes stem borer, and others)

image of the cover of the 2019 applied research report

For questions about the guide, please contact:

Nick Seiter, Field Crop Entomologist | nseiter@illinois.edu

Nathan Kleczewski, Field Crop Plant Pathologist | nathank@illinois.edu

Calculating fungicide net returns

Corn producers in parts of the state are nearing the point in time where they are thinking about fungicide applications to their fields.  In a recent post on my blog I discussed tar spot and also mentioned a recent publication that shows that a single fungicide application at the VT/R1 growth stage has the greatest chance of providing the producer with a return on their investment.  Click here for access to this article.

Nobody knows your farm history and yields better than you do.  That is why running the numbers yourself and thinking about your past experiences can help you determine how likely you are to break even or make a profit using various programs under your specific situation.

To calculate how much yield needs to be protected to break even at a given application cost (fungicide cost plus application costs)  and commodity price:

yield protected (bu/A) = application cost ($/A) / corn price ($/bu). 

This formula can be used to help you determine the amount of protected yield and commodity price needed to break even and see a return on your investment.


For example, to see how much yield would need to be protected by a fungicide to pay for the cost of a  $26/ A total application cost at a $4.50 per bu grain price:

yield protected = ($26.00 per A )/ ($4.50  per bu) = 5.8 bu/ A


the same situation but a program that costs $30 per A =

($30.00 per A)/($4.50 per bu) = 6.7 bu per A. 


Below is a table of the potential protected yields needed to break even at a few different commodity prices and total application costs.

Application cost $3.50 $4.00 $4.50 $5.00 $5.50
$20/A 5.1 bu 5 4.4 4 3.6
$25/A 7.1 6.3 5.6 5 4.5
$30/A 8.6 7.5 6.7 6 5.5
$35/A 10 8.8 7.8 7 6.4
$40/A 11.4 10 8.9 8 7.3


Knowing your application costs for 1 or 2 trips and product, and estimating the commodity price, what sort of yield response will you need?  Have you seen this sort of yield response on your field before or not?  Has this response been fairly consistent? Knowing this information can be very useful in selecting fungicide programs for your specific fields.