Are Modern Corn Hybrids Less Vulnerable to Drought?

It is often repeated that the modern corn hybrids are less vulnerable to drought. Is it true? Well, yes and no. Emerson Nafziger, University of Illinois agronomist, has put together an analysis of corn yields between 1988 and 2012 in Illinois.
In his own words, here is what Emerson found:

“To look at how much yield was lost to drought in 1988 and 2012, I projected trend-line yields for each drought year based on yields over the 30 previous years. The expected (trend-line) yield for 1988 was 129 bushels per acre; the actual yield was 73, so the loss was 56 bushels per acre. In 2012, the expected yield was 173 bushels per acre and the estimated yield is 116, so the projected loss is 57 bushels per acre. Measured in terms of bushels per acre less than expected, the two years are almost identical.
The 1988 yield represents a loss of 44% of expected yield, while in 2012, with higher yield expected, the percentage loss was only 33%. So in relative terms, the 2012 crop lost less yield than the 1988 crop, but in absolute terms, losses were almost identical between the two years.
It’s not clear whether percentage loss or bushel loss is the better measure of drought effects, but what is clear is that serious drought continues to cause serious yield loss, even with today’s faster-growing, higher-yielding hybrids…”

Here is the full article:

Drought Impacts in Illinois

I took some photos on my way back from a Drought Response Task Force meeting in Springfield on August 9. Here are two of the most interesting. The first photo is a farm pond near the Interstate between Decatur and Champaign. Obviously, it is in bad shape.
The second photo shows the “firing” of corn on August 9. This usually indicates a nitrogen deficiency in corn and is common during dry weather. I saw a range of conditions in the corn crop between Springfield and Champaign. Some fields were completely brown while others were relatively tall and green.
What you can’t see from staring out the car window is the condition of the ears on the stalks. However, the August 10 report from USDA predicts that the average corn yield in Illinois this year will be 116 bu/acre, compared to 157 bu/acre in 2011. That’s a 41 bu/acre reduction or a 26 percent drop in yield.
They predict the soybean yield in Illinois will be 37 bu/acre, compared to 47 bu/acre in 2011. That’s a 10 bu/acre reduction or a 21 percent drop in yield.

Farm pond in east-central Illinois (author’s photo). Click to enlarge.

Corn field in Champaign County, Illinois, on August 9. Click to enlarge.