Investigating Hybrid Interactions with Nitrogen and Foliar Fungicides

IPNI-2012-CAN-ON32

23 Feb 2013

2012 Annual Interpretive Summary


Producers recognize that corn hybrids can differ in their response to N fertilizer applications. This study was conducted to investigate such differences among six soon-to-be-released experimental hybrids from two major seed companies. In the 2012 field trial in Ridgetown, Ontario, Canada, hybrids showed large differences in response to N and plant density and their interactions, but little response to fungicides. Grain yield response to a higher N rate than normal varied among hybrids from 13 to 35 bu/A. Responses to a combination of high N and high population varied from 17 to 60 bu/A, depending on the hybrid. The hybrid that responded the most to higher population and N showed greater drought tolerance during a water deficit at the VT (tasseling) growth stage.

The most responsive and highest yielding hybrid produced 263 bu/A at an N rate of 224 lb/A, with agronomic efficiency of 0.64 bu/lb, with the high population without fungicide. The lowest yielding among the six hybrids produced 188 bu/A at 167 lb/A, with agronomic efficiency of 0.36 bu/lb, at the normal population with fungicide. While these results represent only a single growing season and site, they suggest that genetic improvement in hybrids may lead to yield increases as large as 40% resulting from an increase in N use by 34%. Plans to repeat this study in the 2013 season are in place. ON-32