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

Final Report for LNC06-272

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
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Project Information

Summary:

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.

Introduction:

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.

Cooperators

Click linked name(s) to expand
  • Kathleen Delate
  • Joseph Lauer
  • Elmore Roger
  • Deborah Stinner

Research

Materials and methods:

Objective 1. Evaluate the agronomic performance and grain quality of organic certified varieties in pure stands. Varieties evaluated included organically produced hybrids, open pollinated varieties (OPVs), and varietal blends. Seed companies marketing organic seed in Iowa, Ohio and Wisconsin entered organic varieties in the trials. The organic variety performance trials evaluated the agronomic performance and grain quality of varieties in pure stands, the standard procedure by which corn varieties are compared, and was conducted at three university research station locations in each state that have certified organic or transitional organic land available. Each variety entry in the trials was evaluated using three replications per site in a randomized complete block design. Each plot consisted of four 30-inch rows approximately 25 feet long.

Varieties were planted with a commercial type planter adapted for plot planting (and appropriately cleaned before being brought onto certified research plots). A small plot combine harvested grain from the center two rows of each plot. The seed germinability and vigor of each lot of seed was tested. The cold test was used to assess seed vigor. Seed germination and vigor tests were performed in the OSU Seed Biology Laboratory. A qualitative visual weed ranking for each hybrid in the harvest sampling was performed In addition, each variety will be screened for major insect pests of corn.

Objective 2. Investigate differences in grain yield and quality among hybrids planted in pure and mixed stands. Organic hybrids were planted in pure and mixed stands in organically certified fields previously planted to a legume forage crop at five on-farm sites per state. Pure and mixed hybrid plantings were compared in strip trials in which two hybrids were planted on each side of a center strip where the two hybrids were mixed by alternating rows or seed of each hybrid. Mixing was accomplished by filling alternate planter boxes on a conventional corn planter or mechanically mixing seed for planters with central seed hopper delivery systems. Strips were a minimum of 250 feet in length and 75 feet (thirty 30-inch rows) wide. The hybrid treatments (pure vs. mixed hybrids) at each on-farm site were replicated three times in a randomized complete block.

Ear samples were collected to determine if hybrid mixing affects kernel set (pollination success), tip fill, kernel abortion, etc. Ten ears from a 50 foot length of row in the center of each strip plot will be collected to ensure minimal pollen contamination. In plots planted to hybrid mixtures, ears were collected from 10 plants of each hybrid component. Various plant characteristics including early season growth, 50% silking date, plant height, tassel size, and leaf orientation (upright vs. floppy leaves) were measured. Plots were monitored and rated for disease and insect injury if these problems occurred. In plots planted to the hybrid mixtures, disease and insect injury ratings were collected from both hybrid components. A weigh wagon was used for yield determination. A one to two pound grain sample from each plot will be collected from the combine hopper during the harvest operation for grain moisture, grain composition, and test weight determination.

Data collected from the organic performance trial and the hybrid mixture study varied by state and included grain yield, harvest grain moisture, test weight, plant/ear height, final stand, emergence, early season vigor, canopy closure, stalk rot, stalk/root lodging, insect/disease ratings, and weed rankings. Select grain quality attributes including grain protein, oil and starch were determined. Grain samples collected for compositional analysis were submitted to the Iowa State University Grain Quality Laboratory for NIR analysis.

Results were posted on university online newsletters and organic program websites. Articles reporting the project and its results were published in the OCIA newsletter and others. Articles were sent to the popular farm press news journals serving the states involved and the national farm press.

Research results and discussion:

Objective 1: Organic variety performance trials were conducted at three test locations in each state. Varieties evaluated included organically produced hybrids, open pollinated varieties, varietal blends, and conventionally produced hybrid (untreated seed). Seed companies marketing organic seed in Iowa, Ohio and Wisconsin were invited to enter organic varieties in the trials. Open pollinated varieties and varietal hybrids were obtained from Dr. Linda Pollak, USDA corn geneticist/breeder at Iowa State University, Dr. Richard Pratt, corn geneticist/breeder at the Ohio State University, and Dr. Walter Goldstein, Michael Fields Agricultural Institute Research Program Director. The organic variety performance trials evaluated the agronomic performance and grain quality of 20 to 30 varieties in pure stand at field sites in each state that were certified organic or transitional organic. Each variety entry in the trials was evaluated using four replications per site in a randomized complete block design. Data collected included grain yield, emergence, seed germinability and vigor, stalk rot and lodging, grain protein, oil and starch.

Objective 2: Organic and conventionally produced hybrids (untreated seed) were planted in pure and mixed stands in organically certified fields at five on-farm sites per state. Pure and mixed hybrid plantings were evaluated in strip trials in which two hybrids were planted on each side of a center strip where the two hybrids were mixed by alternating rows or seed of each hybrid. Mixing was accomplished by filling alternate planter boxes on a conventional corn planter or mechanically mixing seed for planters with central seed hopper delivery systems. Strips were a minimum of 250 feet in length. The hybrid treatments (pure vs. mixed hybrids) at each on-farm site were replicated three times in a randomized complete block. Ear samples were collected to determine if hybrid mixing affects kernel set (pollination success), tip fill, kernel abortion, etc.. Ten ears from a 50 foot length of row in the center of each strip plot were collected to ensure minimal pollen contamination. In plots planted to hybrid mixtures, ears were collected from 10 plants of each hybrid component. Data collected included grain yield, test weight, emergence, seed germinability and vigor, stalk rot and lodging, grain protein, oil and starch. Farmer collaborators determined yield using weigh wagons or on-farm scales. A one to two pound grain sample from each plot was collected from the combine hopper during the harvest operation for grain moisture and grain composition.

Research conclusions:

The organic variety trials increased organic farmer access to research-based information on varietal performance in pure and mixed stands. The results increased the ability of organic growers to apply research based information in variety selection. The results may also benefit to seed companies starting to market organic seed, thereby providing organic growers with more options in their selection of seed.

Before the implementation of the National Organic Program (NOP), organic farmers generally used untreated corn seed of conventional varieties they knew and trusted from years of trial and error on their farms. Since the implementation of the NOP in October 2002, this situation has changed, and now certified organic farmers must use certified organic seed unless it is not available. Although several seed companies have started to market organically produced, untreated corn seed in accordance with the new organic production guidelines, many organic growers continue to use untreated seed of conventionally produced hybrids. A recent survey conducted by the Organic Crop and Improvement Association – Research and Education indicated that about one third of the organic corn farmers in Iowa, Wisconsin, and Ohio plant untreated seed of conventionally produced hybrids.

Some organic corn growers have expressed reservations concerning the yield potential seed, and grain quality of organically produced corn compared to conventionally produced corn. Some contend that the organically produced hybrids currently available do not have as high yield potential as conventionally produced hybrids. Results of these 2008 multistate organic variety tests indicate that organic hybrids are available with yields comparable to conventional corn hybrids commonly planted in organic cropping systems. Test results also indicate that seed germinability and vigor of organic and conventional seed was similar. Grain protein and oil of organic and conventional hybrids was slightly less than open pollinated hybrids. However, the latter generally produced yields only 1/3 to ½ those of the organically and conventionally produced hybrids.

The on-farm blend study results indicate that mixed stands provided little yield advantage over pure stands. Effects of blending hybrids on grain composition were variable but relatively small. The protein content of grain from the mixed hybrid plantings was either similar to that of the hybrid with the higher protein content in pure plantings or intermediate that of the two hybrids in the pure plantings. Oil content of the grain from the mixed plantings was intermediate that of the grain for the two hybrids in the pure planting. Differences in the starch content of grain from the hybrid blends and the hybrids in pure plantings were negligible.

Participation Summary

Educational & Outreach Activities

Participation Summary

Education/outreach description:

“Selecting Corn Hybrids for Organic Cropping Systems.” 2010 Annual OEFFA (Ohio Ecological Food and Farm Assoc.) Conference, Johnstown ,OH.

P.Thomison, D. Stinner, J. Lauer, L. Freehill, L. Abendroth, R. Elmore, A. Geyer, R. Minyo, and A. Tunink. 2009. Evaluation of the Agronomic Performance and Grain Quality of Organic Certified Varieties. ASA-CSSA-SSSA Abstracts.

P.Thomison, D. Stinner, J. Lauer, L. Freehill, L. Abendroth, R. Elmore, A. Geyer, R. Minyo, and A. Tunink. 2009. Seed Quality of Organic-Certified Organic Corn Hybrids. ASA-CSSA-SSSA Abstracts.

Thomison, P. R., Elmore, R., Lauer, J., Stinner, D. H., Delate, K., Newman, S., and Geyer, A. B. 2007. Organic corn production practices across the Corn Belt. In Agronomy Abstracts ASA, Madison WI.

Peter Thomison. 2009. Organic Corn Production. Columbus, OH: OEFFA/Ohio State University. Ohio Ecological Food and Farm Association Organic 201 Workshop FactSheet.

Peter Thomison, Deborah Stinner, Joseph Lauer, Leslie Freehill, Lori Abendroth, Roger Elmore, Allen Geyer, and Richard Minyo, and Angie Tunink. 2009. Evaluation of the Agronomic Performance and Grain Quality of Organic Certified Varieties and Hybrids.. Columbus, Ohio: OEFFA/Ohio State University. OEFFA Organic 201 Workshop FactSheet

Peter Thomison1, Allen Geyer, Andy Evans, Deborah Stinner, Joseph G. Lauer, Roger Elmore, Lori Abendroth and Leslie Freehill. 2009. Seed Quality of Organic-Certified Corn Hybrids. Columbus, Ohio: OEFFA/Ohio State University.OEFFA Organic 201 Workshop FactSheet

Thomison, P., D. Stinner, A. Geyer, R. Minyo, A. Sundermeier 2008 Ohio State Organic Corn Performance Test. Crop Observation and Recommendation
Network Newsletter.

“Researchers put organic hybrids on trial”. Ohio Farmer. March 28, 2008
(Featured: Peter Thomison, OARDC, OSU Extension, Horticulture and Crop Science; Deb Stinner, OARDC, OFFER)

“2008 Organic Corn Performance Trials.” Thursday, August 2008. 2007 OSU Sustainable ag team field day: organic grain research.

“2007 Organic Corn Performance Trials.” Thursday, August 2008. 2007 OSU Sustainable ag team field day: organic grain research.

“Organic Corn Farming in Ohio, Wisconsin, and Iowa.” Ohio Private Crop Consultants April 4, 2008 Meeting .

“Corn Research Update.” July 20, 2008. Seed Consultants Agronomic Training Seminar at the OSU Western Agric. Research Station.

“Ohio State University Corn Organic Variety Testing Program.” Thursday, September 04, 2008. Organic Seed Company Field Day.

“Organic Corn Variety Test.” Thursday, August 28, 2008. OFFER field day.

“Organic Corn Production: Challenges and Opportunities”. Mid Atlantic Crop Management School. Ocean City, MD/ Nov. 19, 2008

“Determining Marketing Outlets and Choosing the Best Crop Variety to Serve those Markets.” Tuesday, December 02, 2008. Organics 101 Workshop OEFFA Education.

Project Outcomes

Recommendations:

Areas needing additional study

Development of protocols that will enhance plot uniformity in organic hybrid trials (e.g. planting date, weed control.

Evaluate the performance of commercially available organically produced hybrids with conventionally produced non-transgenic and transgenic corn hybrids in organic and conventional environments to assess if genetics associated with organically produced hybrids shows any evidence of “lagging” behind that associated with transgenics.

Evaluate the performance of commercially available organically produced hybrids and conventionally produced non-transgenic and transgenic corn hybrids in early and late plantings (latter simulate plantings often used by organic producers.)

Evaluate the performance of various open pollinated varieties and varietal hybrids especially grain quality.

Compare performance of various open pollinated varieties and varietal hybrids with commercially available organically produced hybrids and conventionally produced non-transgenic and transgenic corn hybrids for use in silage production.

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.