By Darren Hefty

When it comes to fungicide use, there are really two goals and one big consideration. The goals are:

  • Protecting your crop against yield and quality robbing diseases
  • Plant health benefits

Your only consideration is this – will an application of fungicide give me a good return on investment this year?

Corn

There are two post-emerge timings being widely used in the industry. The V4 to V7 window is growing in popularity because you can treat the corn with your ground rig and likely just add the fungicide in with your herbicide spray. We have seen the best results when spraying at V6 or V7. Many trials have been showing a 5 bushel advantage when spraying at this timing, even in drier areas. If you haven’t tried this, we suggest you run some strip trials in your operation with a product like Priaxor or Fortix. The other window is after the corn is fully tasseled, so right around R1 (silking). This has been fairly popular in irrigated corn and in areas with heavy disease pressure. In those situations, a 15 bushel gain is not uncommon, but in arid climates and dryland farming, it has been tougher to get a good return on investment.

Soybeans

In soybeans, nearly all the effort with fungicides is placed on protecting the plants during the reproductive stages. If you’re concerned with sclerotinia white mold, the very best program is to spray Cobra before flowering and follow up with Domark at first flower (R1) and Domark again at first pod (R3). In the absence of white mold, spraying at R2 (full bloom) to R3 (first pod) should be your target. We have found across the country that this timing almost always gives a positive gain when using a product like Priaxor or Fortix. We are going to be doing more work in the future at earlier timings to see if a treatment in the vegetative stages might also pay. I would argue that early diseases like septoria brown spot may be holding back yields by 5 percent, 10 percent or maybe even more. I challenge you to look at your beans throughout this month and watch for brown spot on the lower leaves. Split a field or run some strips, and see if a fungicide at this time of year can make a positive economic difference. Otherwise, spray at R2 or R3 for the most proven timing.

Wheat

  • Herbicide Timing – This is the most popular timing, as it is easy to throw a fungicide in when you are already spraying. Plus, using a half rate of fungicide here gives an almost guaranteed good ROI. Priaxor, Stratego and Quilt have been the products of choice at this timing.
  • Flag Leaf – This has been shown to be the single most important timing on average in terms of yield and ROI, but it is also the least popular because many farmers don’t want to make an extra trip. Twinline, Stratego and Quilt are the most popular products here.
  • Heading (15% Flowering) – If you want protection from late season rusts as well as fusarium head scab, the best products are Prosaro or Caramba. Orius at $2 per acre is far less expensive, but also not nearly as good on scab.

Finally, let’s talk resistance management. Strobilurin (Headline, Quadris, Evito, etc.) resistance is well-documented around the world. That’s why Fortix, Priaxor, Quilt and Stratego (all containing two modes of action) have become so popular

There are a lot of decent fungicide products to choose from in each crop. Don’t be afraid to experiment a little bit. That’s what we’ve done and how we’ve found good returns when using the right products at the right timing in almost every crop. I’ve been pleasantly surprised at the yield gains we’ve seen on our farm from fungicides. I believe you will be, too.