V5 fungicide applications to corn
The benefit has been verified that a fungicide application near V5 stage of field corn growth can result in yield benefit in most situations. Of course, the amount of benefit varies based on the weather and the production practices of the individual corn grower.
Technical and field trial investigation of applying a fungicide at the V5 stage of growth really increased starting in 2008, according to the fungicide manufacturers selling the most product in the corn market.
BASF, the company that led the charge in fungicide application to corn with Headline fungicide, notes investigation of application timing at all stages of corn growth began in 2003. “What we have seen historically and what we have continued to see is that the early timing of V5 or V6 vegetative growth stage fungicide applications have on average, across the board, resulted in yield response in the five-to-seven bushels range,” said Nick Fassler, BASF, technical marketing manager, fungicides.
Last year, Syngenta and Bayer CropScience worked with a large number of corn growers to verify their products’ abilities to help corn reach its yield potential by protecting the corn plant from early-season diseases.
Bayer CropScience conducted trials with its new Stratego YLD and saw farmer-field yield advantages greater than non-treated acres for a V3 to V6 application averaging 8.3 bushels per acre.
The largest number of field trials in 2010 was conducted by Syngenta with a Quadris application between V4 and V8. Variation in application timing can be accounted for by Syngenta relying on farmer cooperator application in 166 total fungicide trials, not all of them limited to early-season timing. Of those trials with an early-season application, the overall national average was about six bushels per acre positive yield response.
The intense interest in fungicide use on corn in 2010 also confirmed that the standard corn fungicide application for the most yield advantage is still at the tassel stage of corn.
“Most of the earliest research work was done around VT to R1, and in fact, that is still where we see the greatest yield benefit. But we have determined that by going early growers can also recognize additional yield benefit, albeit not as high as we typically see with a later application,” said Eric Tedford, Syngenta, fungicide technical brand manager.
Tedford provided examples of the variation in yield advantages using an approximate V5 application plus a R1 application. Minnesota trials of Quadris early followed by Quilt Xcel at R1 showed a 32.1 bushel average yield advantage compared to non-treated corn in 34 trials. Illinois trials
for the same applications in 27 fields showed a 16.6 bushel average increase.
On a national basis, Bayer CropScience calculated an average 15.2 bushels per acre advantage when using Stratego YLD no later than V6 and again at R1. BASF reports its years of data show a range of a 16 to 20 bushel per acre yield improvement for an early-season plus R1 sequential application of Headline compared against non-treated check fields.
The difference in national average yield per company can be explained to a degree by where the trials were conducted and the overall agronomics used to grow the corn in trial fields.
“We are seeing the greatest from V5 fungicide applications in corn-on-corn production practices. We see much higher disease pressure in these fields; so, it is critical to keep the young corn plants healthy and disease free during the ear development stage between V3-V6. Anthracnose leaf blight can infect the plants during this time, which leads to stalk quality issues later in the season. Disease in general also flourishes more in high-population plantings and narrow-row production, said Ethan Luth, Bayer CropScience, crop marketing coordinator.
“The early application is additive with a late-season application; it is a nice addition for guys that are really driving yield potential, but that application is our second recommendation after a tassel application,” said Fassler.