Late-Season Fungicide Applications

The big question right now is whether fungicide is still worth applying on corn and soybeans this late in the season.

For soybeans, we are still within the optimum window to see a yield benefit. R4, the stage when pods at the top of the plant are about ¾ inch long, is typically the end of the fungicide window. Many fields are just now reaching this point, so there is still time to protect the crop. Given how the season has gone and the strong yield potential, keeping the plant healthy through August makes sense. There are a lot of pods out there, and anything we can do to reduce pod abortion will help maximize yield.

Corn is a bit trickier. Southern rust is starting to show up and can cause significant yield losses. Some of the earlier planted corn has already reached the dent stage. In those cases, it is usually not worth applying fungicide. We rarely see a yield bump after corn reaches dent, especially with 110-day hybrids or earlier.

However, later planted or longer season corn still in the R3 (milk) stage is a different story. There is still plenty of time for grain fill, and protecting that corn can help maximize kernel development. You can get by with a more economical fungicide now, since we do not need extended residual control. Headline Amp has been our go-to option the last couple of weeks and continues to perform well for disease control in corn.

We are still actively scouting. If you are wondering whether a late-season fungicide application could help your crop, give SFG a call.