A lot of attention has been focused on applying fungicide to the corn crop and I will go on record as one who supports this practice, mostly because you can book new crop corn at over $6.00. But I have a couple of bones to pick with the more vigorous promoters.
1. Yield Advantage. There are reports of +20 bu per acre yield advantages for fungicide application on corn. Anyone thinking this type of response is typical and achievable is talking through their hat and more interested in taking money from our pocket and putting it into theirs. The manufacturers claim that yield advantages are in the 8 -11 bu/acre range plus some potential benefits to standability and DON levels if you use Proline.
Brian and I have accumulated 3 years of side-by-side data using ground equipment. Our average yield advantage has been a solid 5.5 bu per acre, with the range from plus 3 to plus 9 bu per acre. A 5-7 bu yield advantage is probably more the norm than the exception. OMAFRA research is in the 5-7 bu range as well.
2. Application Method. There is only one way to put fungicide on corn. Take to the air. There are too many cowboys talking about ground application who have never driven a high clearance sprayer across a corn field. GPS is a great tool, but common sense must come into the equation. Sprayer jockeys are getting too used to letting their auto steer do all the work. Unless the GPS planter data can be loaded into the sprayer's GPS, you are asking for trouble. The sprayer will knock down too much corn and it won't come back. Even if the sprayer jockey takes the time to steer the machine down the row, he will run over some corn. Sprayer boom widths and planter widths don't match up very well and variable guess row widths make it worse. Sitting in the sprayer seat, the decision becomes whether to beat up the row under the right wheel or the row under the left wheel. Munching down 1 row out of 40 equals 2.5% loss.
We have measured the rows that run under the sprayer axles and found there can be a 4 bu /acre yield loss on these rows. When corn is in full tassel these plants take a beating. The faster the ground speed, the worse the beating. And we haven't talked about headland losses yet.
Add it all up and our solid 5.5 bu per acre advantage soon dwindles to the 4.5 bu territory.
Do yourself a favour and put the extra bushel toward the airplane. The deer and the raccoons take out enough corn without us tramping more into the ground.