Source: Winfield United Agronomists
Will it pay to apply a fungicide this year? If we could look into the future, it would be easy to make that call today. Since that’s impossible, my best advice is to use data and common sense to determine the best course of action to protect plant health.
Start with seed
You already have access to data that can help you determine whether return on investment with a fungicide application is more likely. First, l recommend looking at your seed guide. Most companies rate hybrids and varieties for their tolerance to specific diseases. Seed choices with lower tolerance to diseases are good candidates for fungicide protection.
While the seed guide is a good place to start, Answer Plot data from WinField United provides more about in-season results. Each year, we test 240 hybrids across seed brands to determine response-to-fungicide (RTF) scores. Unlike most seed guides, which base disease ratings on visual observations, Answer Plot data is used to calculate the potential yield response of a fungicide application by hybrid. The trials are replicated more than 200 times to account for different growing conditions and geographies. Data from 2017 Answer Plot trials showed a fungicide yield response averaging 11.2 bushels per acre across tested hybrids when MasterLock adjuvant was included in the tank mix. Yield response ranged from -4 to 38 bushels per acre, which reinforces different hybrid responses to fungicide application.
Survey conditions and act
Once you understand where you’re likely to see the best response to fungicide, it’s time to survey fields. Scout early and often, especially if environmental conditions favor disease development. In general, you’ll see the best return on investment when applying a fungicide at tassel time. But if disease starts early and is progressing quickly, a V5 application can help protect plants until tasseling.
Get the most value from your fungicide treatment by adding an adjuvant like MasterLock to the tank mix. Effective crop protection depends on good coverage. It’s not about the ounces of product per acre that you spray — what’s important is that the active ingredient is actually reaching the plant. MasterLock optimizes droplet size to reduce drift potential and help ensure more product penetrates into the canopy. It contains a surfactant to help cover more leaf surface area.