Organic Corn Variety Trial

Mideast Organic Corn Variety Trial, 2012

By Michael Bomford, Jake Schmitz, and Tony Silvernail

Organic Valley
                logoThis material has been adapted from a factsheet (715 KB PDF) and talk (1.8 MB PDF) presented at the Organic Corn Workshop in Bowling Green, KY, and a poster presented at the Southern Sustainable Agriculture Working Group conference in Little Rock, AR. Both events were in January, 2013.

Introduction

Organic feed corn prices have fluctuated between $7 and $17 per bushel since 2011, reaching a record high in the fall of 2012 (price report PDF). High feed prices represent a barrier to organic livestock production, but also represent an opportunity for organic farmers who are able to grow their own corn.

Organic farmers are required to plant certified organic seed, if it is commercially available. Conclusions drawn from conventional variety trials are not necessarily applicable to organic operations.


Objectives


Methods

In the summer of 2012, Organic Valley and Kentucky State University coordinated organic corn variety trials on ten organic farms across Indiana, Kentucky, Ohio, and Pennsylvania. The western part of this region suffered moderate to extreme drought for much of the summer.

Locations

Approximate locations of farms involved in organic corn variety trial, relative to Mideastern cities. Each participating farm is shown by an ear of corn.

Drought
                      Progression

Drought progression across Mideastern US between April and September, 2012. Yellow pins show locations of farms involved in organic corn variety trial.

Short, medium, and full season varieties donated by five organic seed companies were compared at each location. Each variety was tested in four rows on at least four organic farms, using standard production practices employed by experienced farm managers. Rows ran the entire field length. Farms served as replicates; treatments were not replicated on each farm.

Harvest was conducted from a 20-foot row section, beginning 20 feet from the end of the second  row for each variety. Yield is reported on a 15% dry matter basis.


Organic corn varieties planted at the Kentucky State University Research and Demonstration Farm, 2012. Drag image to pan. Click arrow in top right corner of image to zoom to full screen.


Organic corn varieties tested, by supplier and season length
Season Requirement American Organic (AO) Blue River Organic Seeds (BR) Doebler's Pennsylvania Hybrids (DB) Great Harvest Organics (GH) Masterís Choice (MC)
Short (<95 days)


40R73


Medium (95-105 days) 4G10 4G52
4G34
45R37
48B30
N524 40B8
44B8
OG-4830
OG-5250
Full (>105 days)
exFG06
D918
4FG06
57H36
70R70
N630
N631
59R5
61R2
OG-535
OG-6060


Results

The average yield for the trial was 142 bu/ac, exceeding the national average yield of 123 bu/ac (USDA-ERS tables). Yield varied significantly between locations, ranging from 64 bu/ac in western Indiana to 190 bu/ac in central Ohio. Drought severity probably accounted for much of the difference between locations. Differences between varieties were less pronounced than differences between locations.


Bushels per acre

Yield by Location

Average yield (bu/ac) of organic corn at each of the ten trial locations. Means shown by green bars are significantly higher than those shown by red bars (t-test, α=0.05).
Bushels per acre
Yield by Variety
Average yield (bu/ac) of organic corn for each of 22 varieties tested. Means shown by green bars are significantly higher than those shown by yellow bars (t-test, α=0.05).

Top performing varieties were:


Follow-up

The trial is being expanded and repeated in 2013.


Acknowledgments

Thanks to:


Updated 03/27/14


College of Agriculture, Food Science and Sustainable Systems