Mideast Organic Corn Variety Trial, 2013
By Michael Bomford, Jake Schmitz, and Tony Silvernail
This material has been adapted from a talk presented at the March 2014 Organic Association of Kentucky (OAK) conference in Berea, KY, and posters presented at the January 2014 meeting of the Southern Sustainable Agriculture Working Group (SSAWG) in Little Rock, AR and the February 2014 meeting of the Midwest Organic and Sustainable Education Service (MOSES) in La Crosse, WI.
Organic feed corn prices have fluctuated between $10 and $17 per bushel since 2012, reaching a record high in the fall of 2012 then falling to $11 per bushel in early 2014 (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. Organic corn variety trials are needed to
identify the best varieties available to organic corn growers.
- Aid organic corn growers in the Mid-East region in selection of varieties based on data specifically suited to their regional climate and soils.
- Demonstrate successful organic corn production systems to farmers interested in working with the crop.
In the summer of 2013, Organic Valley and Kentucky State
University coordinated organic corn variety trials on 567
plots spread over 26 certified organic farms in six states
(Fig. 1). Seven organic seed suppliers donated seed for the
trial. This was the second year of the multi-state on-farm
Growing conditions were good to above average at most
locations, with ample rainfall. A cool wet spring delayed
planting, and subsequent harvest, in many of the northern
locations. Several northern farms that attempted to
participate in the study had to be excluded due to late
harvest, leading to inadequate grain drying.
| Figure 1. Approximate locations of
farms involved in organic corn variety trial. Each
participating farm is shown by a red circle.
organic corn varieties (Table 1) were compared for yield and
quality parameters (starch, protein, oil, and density). An
open-pollinated variety was used as a check at each site. Each
corn plot consisted of four rows of corn, running the entire
field length. Between 9 and 44 (mean 22) corn plots were
planted on each farm. Varieties were assigned to farms, then
randomly distributed between available plots on each farm.
Plots were managed using standard production practices
employed by experienced farm managers. Farms served as
replicates; varieties were not replicated on individual farms.
Only varieties grown on at least four farms were considered in
season varieties were distributed to northern farms, where
growing seasons are shorter. A wet spring and late harvest in
the northern region of the study area made much of these data
unusable, resulting in less replication of short season
varieties (n = 4 - 6) than other varieties (n =
10 - 26). Poor drying and mold infestation precluded most
quality analysis for these varieties.
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 15.5% moisture basis. Quality analysis
was conducted at the Iowa
Grain Quality Initiative Lab.
used to test for farm and variety effects on grain yield,
density, and content of starch, protein and oil. Means were
separated by Tukey's test. Correlations between yield and
quality parameters were also examined.
|Season Requirement||Albert Lea
|Great Harvest (GH)||Masterís Choice (MC)||Merit Seed
|Medium (96-105 days)||0.57-04N
The average yield for the trial was 159 bu/ac (Fig. 2), the
same as the national average corn yield for 2013 (USDA-ERS,
2014). All study sites were organic farms, so no direct
comparisons to conventional corn yields were conducted.
Yield varied significantly between farms, ranging from 90
bu/ac in northern Indiana to 231 bu/ac in central Ohio (Fig.
2). Differences between farms were more pronounced than
differences between varieties. Ohio yields were higher than
Indiana yields, on average, but no other significant
differences were detected between states. Higher yielding
farms were not clustered in any particular subregion.
Season length was positively correlated with yield (Fig. 3).
Each additional day of season length gave an additional bushel
of corn per acre, on average.
Top-yielding varieties were (Table 2):
Other top performers included (Table 2):
Grain yield was positively correlated with protein and
density, but negatively correlated with starch content (Fig.
4). Starch content was negatively correlated with all other
quality parameters. The negative correlation between starch
and protein content was particularly pronounced.
|Figure 2. Average yield (bu/ac) of
organic corn at each of the trial locations. Means
labeled with the same letter do not differ
significantly (Tukey's HSD test, a=0.05).
|Albert Lea||0.6710||13||98||150 abcd||8.0 abcd||4.3 abcd||72.5 abcde||1.28 bcdefg|
|Great Harvest||5475||25||108||164 abcd||8.8 abc||3.8 defgh||72.1 bcde||1.28 bcd|
|Great Harvest||6175||10||112||197 a||8.6 abcd||3.8 cdefghi||72.4 abcd||1.28 bcdef|
|Great Harvest||6543||13||113||170 abcd||8.4 abcd||3.8 defghi||72.5 abcd||1.28 bcdef|
|Albert Lea||0.57-04N||12||104||150 abcd||8.6 abcd||4.1 abcdef||71.8 bcde||1.26 fghi|
|Albert Lea||0.59-06N||23||106||162 abcd||8.2 bcd||4.2 abc||72.1 bcde||1.26 fgh|
|Albert Lea||0.69-99N||15||99||153 abcd||8.3 abcd||3.9 abcdefghi||72.1 abcde||1.25 efghi|
|Albert Lea||0.79-96N||5||96||131 abcde||-||-||-||-|
|Great Harvest||37N4||13||97||157 abcd||9.0 abcd||3.8 abcdefghi||71.9 abcde||1.30 abc|
|American Organic||3G33||16||97||133 de||8.4 abcd||4.0 abcdefgh||72.0 abcde||1.25 ghi|
|Albert Lea||40-07N||22||107||168 abcd||8.5 abcd||4.0 abcde||72.3 abcd||1.28 bcdef|
|Blue River||43L96||21||98||142 bcde||8.9 abcd||3.8 bcdefghi||71.6 bcde||1.26 cdefghi|
|Blue River||48B30||17||102||155 abcd||8.4 bcd||4.0 bcdefg||72.3 abcd||1.28 bcdef|
|Albert Lea||50-04N||21||104||157 abcd||8.0 cd||3.7 fghi||72.9 ab||1.26 defgh|
|Blue River||51B57||22||103||175 ab||8.0 cd||3.7 fghi||72.5 abcd||1.24 i|
|Albert Lea||53-09N||19||109||149 bcd||8.3 bcd||3.9 bcdefg||72.3 abcd||1.27 cdefgh|
|Great Harvest||56L3||17||106||162 abcd||9.1 ab||3.7 efghi||72.4 abcd||1.32 a|
|Blue River||57L96||13||107||137 cde||8.7 abcd||3.8 defghi||71.7 cde||1.25 hi|
|Albert Lea||60-01N||23||101||162 abcd||8.2 bcd||3.9 cdefg||72.5 abcd||1.28 bcdef|
|Great Harvest||63T1||13||112||181 ab||8.1 bcd||3.5 i||73.2 a||1.29 bcd|
|Blue River||67H19||14||113||150 abcd||9.1 ab||4.2 ab||71.1 e||1.27 bcdef|
|Blue River||70R50||12||114||155 abcd||8.5 abcd||4.1 abcd||71.9 bcde||1.28 bcdef|
|Blue River||76H50||12||117||158 abcd||8.6 abcd||4.2 abc||71.4 de||1.27 cdefgh|
|Doebler's||N581||21||107||163 abcd||8.8 abc||3.8 defghi||72.3 abcd||1.29 bc|
||110||171 abc||8.3 bcd||3.9 cdefg||72.3 abcd||1.26 efgh|
|Doebler's||N631||15||110||175 abcd||8.5 abcd||3.5 hi||72.8 abc||1.28 bcde|
|Merit Seeds||O-346||4||90||150 abcde||-||-||-||-|
|Merit Seeds||O-646||23||109||166 abcd||8.6 abcd||4.2 abc||71.8 cde||1.28 bcde|
|Master's Choice||OG-4430||5||94||142 abcde||-||-||-||-|
|Master's Choice||OG-4590||6||95||127 bcde||7.4 abcd||3.9 abcdefghi||72.7 abcde||1.23 efghi|
|Master's Choice||OG-5090||21||100||159 abcd||8.3 bcd||4.3 a||71.9 bcde||1.27 bcdef|
|Master's Choice||OG-535||22||107||164 abcd||7.9 d||3.9 cdefgh||72.7 abc||1.25 ghi|
|Master's Choice||OG-6060||23||110||155 abcd||8.3 bcd||3.8 defghi||72.6 abc||1.27 cdefg|
|Open Pollinated||OP||22||110||102 e||9.4 a||3.7 ghi||71.8 cde||1.29 b|
|American Organic||X3G03||4||92||145 abcde||-||-||-||-|
*Means followed by the same letter within a column do not
differ significantly (Tukey's HSD test, a=0.05).
| Figure 3. Relationship between
season length and corn yield.
| Figure 4. Relationships between
yield and quality parameters. Density expressed in
g/mL; other quality parameters are % of grain weight.
The on-farm studies demonstrate successful organic corn
production, with excellent yields from a wide range of organic
corn varieties. Most commercially available organic hybrids
had higher yields than the open-pollinated variety tested.
Full season varieties tended to out-yield short season
Differences between farms were more pronounced than
differences between varieties, suggesting that variety
selection is less important than farm management and other
Farmers must consider both yield and quality parameters when
deciding which organic corn varieties to plant. Yields were
positively correlated with protein content and grain density,
suggesting that high yield does not preclude high quality.
Curiously, the open pollinated variety had both the lowest
yield and the highest protein content among the varieties
tested. Starch content was negatively correlated with yield
and all other quality parameters, yet the variety with the
highest starch content, Great Harvest 63T1, was also among the
top yielders. Careful variety selection, coupled with good
farm management, can result in high yields of high quality
Further study is needed to identify farm and soil
characteristics that contribute to optimal performance of
available organic corn varieties.
A similar trial was conducted in 2012.
The trial will be repeated in 2014.
- Seed Suppliers: Albert Lea, American Organic, Blue
River Organic Seeds, Doebler's Pennsylvania Hybrids, Great
Harvest Organics, Master's Choice, and Merit Seeds
- Organic Valley: Jake Schmitz, Kevin Kiehnau, and Lowell
- Kentucky State University: Tony Silvernail, Jon Cambron,
Marlon Bascombe, Cynthia Rice, Kirk Pomper, and Teferi
- Ohio State University: Brian McSpadden Gardener
- Farmer Cooperators: Dennis Buck, Charles Eselgroth, Daniel Fullencamp, Thomas Heckman, Sam King, Tim Kline, Pete Lehman, Lloyd Martin, Stuart Mattingly, Allen Miller, Bill Miller, Glen Milner, Ron Milner, David Osterloh, Roger Peters, Myron Raber, Raymond Rayber, Elvin Ranck, Kenneth Sauder, David Shively, Levi Stoltzfus, Melvin Troyer, and Larry Wiever
- Funders: Organic Valley, USDA-NIFA