Evaluating Corn Varieties in Pure and Mixed Stands for Organic Crop Production across Three States in the Corn Belt

Project Overview

Project Type: Research and Education
Funds awarded in 2006: $138,252.00
Projected End Date: 12/31/2008
Region: North Central
State: Ohio
Project Coordinator:
Dr. Peter Thomison
Ohio State University

Annual Reports


  • Agronomic: corn


  • Education and Training: demonstration
  • Production Systems: agroecosystems


    Corn organic variety trials were conducted in Iowa, Wisconsin, and Ohio in 2007 – 2008 with three tests per state. Varieties evaluated included organically produced hybrids, open pollinated varieties, and untreated conventionally produced hybrids marketed in each state. Up to five evaluations of varietal blends were performed in each state using replicated on-farm strip tests. Data collected included grain yield, emergence, seed germinability and vigor, stalk lodging, grain protein, oil and starch. Results have been presented online, at field days, and publicized in newsletters and the popular farm press for distribution to organic farmers.


    Variety selection is a key step in successful corn production. In 2004 organic variety tests conducted in Ohio and Wisconsin, differences in yield among organic varieties ranged from 30 to 50 bu/A. These results demonstrate the economic advantage that organic farmers could obtain by planting high yielding organic varieties that are adapted to their regions. The magnitude of the yield difference also indicates that growers could benefit from organic corn performance trials to help them identify promising hybrids. At recent meetings of the Organic Crop Improvement Association, the Innovative Farmers of Ohio and Ohio Ecological Food and Farming Association, variety testing under organic conditions has been identified as a high priority research area. A survey of organic crop producers in Ohio indicated that variety selection was one of their top concerns.

    Since the implementation of the National Organic Program in 2002, several seed companies have started to market organically produced, untreated hybrid corn seed in accordance with the new organic production guidelines. However, many organic farmers have expressed concerns that seed of organically produced hybrids does not perform as well as the untreated conventionally produced seed they previously used. To the best of our knowledge, it is not known whether this problem is due to the seed corn production environment, the conditioning process, or an inherent characteristic of certain hybrids. Results of performance trials would help growers avoid hybrids affected by such problems. The variety testing would also help establish the creditability and reliability of small seed companies that are starting to market organic corn seed. There have also been questions about differences in the feed value for dairy cows of the grain produced by organic corn hybrids. Such nutritional information is needed as the demand for organic dairy products increases.

    Results of recent studies in South Dakota and Minnesota indicate that farmers may improve grain yield and protein content of corn without additional inputs by mixing varieties of different parentage and similar flowering date in the same field. Studies with various cereals have shown that varietal blends can enhance yield stability and help minimize yield losses from various foliar diseases. The use of blends to manage foliar diseases in corn has received little attention in conventional and organic corn production. However, the potential benefits of mixtures of corn varieties in organic crop production have not been investigated.

    State agricultural universities in the Corn Belt conduct annual hybrid performance trials with large numbers of hybrids to provide conventional farmers with an unbiased source of information on commercially available corn hybrids. However, comparable trials to provide organic farmers with objective information on the performance of organically produced varieties are not available. University variety testing is driven by entry fees paid by companies marketing conventionally produced seed. Presently, the small seed companies marketing organic seed do not have the same level of funds, which the large seed companies do, to support extensive public variety testing programs. Conducting multi-state organic trials in the North Central region will generate high quality public data quickly and provide high impact information to a wide group of organic farmers.

    As more conventional hybrids are introduced containing GMO traits for insect and herbicicide resistance, there is increasing concern that fewer non-GMO hybrids will be available to organic and non-organic corn growers in the future. The scope and scale of this multi-state organic corn testing project will provide evidence to seed companies that a strong demand exists for non-GMO corn across the Corn Belt, which warrants continued development of non-GMO corn hybrids.

    There is a general lack of information on corn variety performance in organic cropping systems in the north central region, which is needed to help organic grain producers select the hybrids best adapted to their farming operations. Organic grain farmers are seeking information and knowledge that will enable them to identify organic varieties that perform best under the varying environmental conditions in organic cropping systems in the north central region. This is becoming increasingly important as demand for organic corn increases locally, nationally and internationally, and as the number of organic farmers increase. Our goal in this project is to provide organic farmers with research-based information they can use to select corn varieties for pure or mixed plantings to optimize grain production and quality under certified organic conditions.

    Project objectives:

    1. Evaluate the agronomic performance and grain quality of organic certified varieties in pure stands.

      Investigate differences in grain yield and quality among corn hybrids planted in pure and mixed stands.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.