Senior Contributor
Posts: 328
Registered: ‎10-18-2016

Drought Tolerant Corn - Really?

[ Edited ]

I'm not sure I see that new corn is especially drought tolerant.  It may be more that newer hybrids are generally more relilable under all stress conditions.


This Nebraska paper is pretty simple.  Drought tolerant traits are not a single gene, which makes it harder to select or design a hybrid.


This study seems to indicate that being drought tolerant may help when moisture is limited but when times are good that trait doesn't produce as well.


Here is an excerpt from Ohio.


"The drought-tolerant hybrid yield advantage was positive when the conventional hybrid yield was less than 185 bu/A, which is the point where the line crosses the x-axis. This value is approximately 10 bu/A above the state yield average for Ohio in 2013 and 2014 (USDA-NASS, 2015). In environments where the yield potential for conventional hybrids was below 185 bu/A (941 occurrences), the drought-tolerant hybrids produced greater yields 61 percent of the time (Figure 3A). When the conventional hybrids produced grain yield greater than 185 bu/A (1,194 occurrences), the drought-tolerant hybrid yield advantage was negative and produced less yield 62 percent of the time (Figure 3B). These results suggest that in moderate to lower yielding environments in Ohio (below 185 bu/A average yield), the drought-tolerant hybrids can produce greater yield than their conventional counterparts under the same management conditions, but the yield may not be greater when conventional hybrids yield more than 185 bu/A. A similar yield advantage was observed in Kansas from using drought-tolerant hybrids where the state yield average was 138 bu/A in 2013 and 2014 (USDA-NASS, 2015). The drought-tolerant hybrids exhibited a yield advantage when the conventional hybrid yield was less than 136 bu/A, but yield was similar between hybrid types when the conventional hybrid yield was greater than 136 bu/A (Ciampitti et al., 2015). In Ohio, the drought-tolerant hybrids exhibited more stable yield than the conventional hybrids in that the low yield was not as low, and the highest yield was not as high. This supports the statements presented by Cooper et al. (2014) that these drought-tolerant hybrids have been bred for improved yield stability across environments. In summary, drought-tolerant hybrids may offer a yield advantage in production environments at greater risk to water deficit with moderate- to low-yield potential."


My take-away on this is I'll go for the best yielding corn without regard to drought tolerance unless I'm in an area where drought is typical.  Not for the Three I states, maybe.  Might be good for western Kansas, Nebraska and so forth.


My deepest appreciation to Meaghan Andersaon, ISU Extension Agronomist for finding these resources.