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  • Writer's pictureRachel

Some Helpful Guidelines for your 2020 Corn Fungicide Application

Here we are; its that time of the year again. Time to talk about foliar fungicide applications in corn. While I could spend a lot of time explaining why you should be applying fungicides and the details, I’ll link some of our previous blog posts to that very topic. This blog will focus on our results the last few years, your options for products, and the importance of timing.

1. Local Results and Return on Investment

Each year we include some check strips across fields across our service area in order to better understand the importance of fungicide. Across four years of data we have seen an average return on 7.5 bushels per acre. That is even including an average return of 2.4 bushels/acre in 2017, which was likely do to only having 2 strips in one location. If we ignore that year due to the small quantity of data we had, the average across three years was 9.2 bushels per acre. In 2019, we saw an average return of 11 bushels per acre with a single fungicide application. To us, this is one of the most reliable applications from a return on investment standpoint.

If we do a rough numbers ROI, using a fungicide cost per acre of $22, and using last years return of 11 bushels per acre, and price of corn as $3.23 we would see a ROI of around $13.50. Pretty good economics for application. Our breakeven would be around 6.8 bushels, below our three year average of 9.2 bushels/ac.

2. Picking a product

There are many excellent products for you to pick from, and I am going to leave that decision between you and your agronomist. I am not here to promote any specific product, but rather provide some framework to help you narrow down your options. First off is modes of action. Any product you select should have multiple modes of action. Fungicides with multiple modes of action will have a greater control of diseases and help prevent any resistance from growing. Secondly, pick something with a longer residual. Select a fungicide option that has at least 14 days of residual. Many on the market currently have as much as 21-28 days of residual. This dramatically improves the control you have over disease pressure

3. Timing

The last thing we need to discuss is timing. Getting the timing window for application can be a bit tricky. Apply too soon, and you risk your residual running out before the peak disease pressure is past. Conversely, apply to late, and you are risking yield loss from disease that could have been prevented with an earlier application. Our goal is to match our application so it covers the peak disease pressure for the crop. So how do we do that? First step: frequent scouting. Checking multiple places within a field for disease pressure and distribution is vital to keep track of how disease is progressing. A rough guideline is to not let disease progress to the earleaf. This is when we might begin to see some yield reduction from disease.

If you have questions about timing your fields, choosing the right product for you, or more on local results, get in contact with one of our agronomists today!

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