Hail annually destroys approximately 1.4 percent of corn. Years like 2009 stand out vividly to many people as major hailstorms cut across parts of Iowa, damaging more than 1 million acres of corn in a single season. Many farmers and agronomists have been interested in the effects of fungicide application on corn after a hail event. In response, a multi-year study looking at mid-season “hail events” with fungicides applied after simulated hail events was completed. Here is a video of the project.
Corn hail trial
The purpose of this three-year trial was to determine if fungicide application to corn damaged by hail at VT or R2 reduced foliar disease severity or improved yield compared to hailed corn that did not receive fungicide.
The fungicide treatments were
- Simulated hail decreased yield every time it was applied.
- In three of five site years, plots with simulated hail had
lessfoliar disease than no-hail controls.
- At the two locations without foliar disease differences between simulated hail plots and
no-hailcontrols, a natural hail event occurred over the entire plot, including the no-hail controls.
- Yield responses were numerically higher with the application of a fungicide after VT and R2 stages in 12 of 20 comparisons in simulated hail plots and in 12 of 20 comparisons in no-hail plots at either the “immediate” or “deferred” application timing at any site year. The
increaseshowever, were not significantly higher at P = 0.1.
Results suggest that in fields with low levels of fungal foliar disease, hail-injured corn plants may have less disease than plants without hail injury. Also, pyraclostrobin +
We are now studying management of crops after hail events during early vegetative growth or during grain fill. Some of the more severe hail events the past few years have occurred earlier in the season. We have already applied “hail storms” to V5/V6 corn at research farms in Kanawha, Iowa, and Ames, Iowa, in 2015, with fungicide applications following at 7-10 days afterward.
Source: Iowa State University