Should I use a Fungicide on my Corn Crop?

Several different Universities have addressed this question in their latest newsletter and all come to the same conclusions. "Fungicides are a very profitable in corn production when diseases that are controlled by the fungicide is present to a susceptible hybrid."

This goes back to the disease triangle that governs whether disease increases to yield limiting levels. Basically three things, when they are in place, cause disease to quickly develop: 1) a susceptible variety /hybrid 2) the pathogen is present and 3) the environmental conditions are suitable. For example we are harvesting our wheat crop and this year we experienced very little head scab. Across the varieties we plant we had susceptible varieties, the head scab fungus was very likely around but the weather conditions were not prime, so we see virtually no scab. In fact for 2009 you could plug several wheat diseases into this picture, with the same result, little disease pressure for 2009 and a fairly clean crop.

The latest issue of Crop Observation and Recommendation Network (C.O.R.N.) Newsletter has yields results from Ohio research last year showed the following "The untreated checks ranged from 73.6 to 177.96 bu/A, with an average of 109.8 bu/A, whereas in fungicide-treated plots, yields ranged from 68.19 to 188.49 bu/A, with an average of 109.55 bu/A. In 12 of the 20 trials, treated plots had numerically higher yields than the checks, however, the yield difference varied considerable from trial to trial. Yield differences between treated and untreated plots (treated minus untreated) ranged from -16.70 to 10.53 bu/A across all 20 trials, with an average difference of -0.28 bu/A. Similar fungicide trials were conducted by university researchers across the Corn Belt, with similar results. Depending on the fungicide, average yield differences between treated and non-treated were between -1.2 and 4 bu/A when foliar disease severity was less than 5% and between 1.6 and 10 bu/A when severity was greater than 5%."

Currently the corn crop does not have a diseases of note. In fact as of my latest scouting I did not see anything at all.

The University of Illinois crop newsletter The Bulletin and Kentucky Corn and Soybean Newsletter also have an article in their edition's this week.