There are several specialty corns currently being marketed for value enhanced grain production. These include the TopCross^®, Supercede^TM, and NutriDense^TM corns.These specialty corns were developed with improved nutritional traits to enhance the feed value of grain. Nutritionally enhanced grains produced by these specialty corns offer major advantages over No. 2 yellow corn because they contain more protein, essential amino acids, and energy (oil) which can help livestock feeders reduce reliance on costly ingredients and supplements.

The TopCross grain production system licensed by Optimum Quality Grains has been available for several years and it is rapidly gaining popularity as a method of producing high oil corn. The TopCross system involves planting a blend (a TC-Blend^® of two types of corn. We have conducted evaluations of TC-Blends used in the high oil TopCross grain production system since 1995. For more information, consult:

                    OSU Extension Fact Sheet AGF-133-98,
                              Performance of high oil TopCross® grain production systems for corn, 1995-1996. ,
          and
                   OSU Extension Fact Sheet AGF136-99,
                             1999 High oil corn TC-Blend® Performance Tests. .

The Supercede and NutriDense corns have been introduced more recently, and we undertook limited testing of Supercede hybrids in 1998. Unlike the TopCross high oil corn production system which involves the use of blends, the Supercede and NutriDense nutritionally enhanced corns are single cross hybrids. The Supercede and NutriDense corn hybrids have been licensed to seed companies for distribution by Dow AgroSciences and ExSeed Genetics, respectively.

In 1999, we conducted performance tests at two Ohio locations comparing Supercede and NutriDense corn hybrids used in nutritionally enhanced grain production. The major objective of these tests was to evaluate the agronomic performance and grain quality characteristics of nutritionally enhanced hybrids that are adapted to Ohio growing conditions and commercially available to corn growers.

The 1999 tests were established at two locations - the Ohio State University (OSU) - Ohio Agricultural Research and Development Research Center (OARDC) at Wooster in northeast Ohio and the OSU-OARDC Northwest Branch Research Farm near Hoytville in northwest Ohio. Eight to nine nutritionally enhanced corn hybrids (including a single cross high oil corn hybrid) from five seed companies were planted at each site. The Supercede corns were represented by two entries - Mycogen 2655 and Mycogen 2654; the NutriDense corns were represented by six entries - Wellman WIN 109 and WIN 111; Anderson EXP110; and Cropland Genetics Countrymark E557, E560, and E565. The single cross high oil hybrid (E618) was provided by Seedway. A normal (low oil) single cross corn hybrid (Pioneer brand 34K77) was also included as a check. Maturity of the entries ranged from 108 to 111 days.

Data from the nutritionally enhanced corn tests were analyzed as a three replication, randomized complete block design experiment at each location. The least significant differences at probability level 0.05 (LSD 0.05) and coefficients of variation (CV%) were calculated from the location analysis of variance.

Testing nutritionally enhanced specialty corns is more difficult than testing normal corn hybrids due to isolation requirements. If pollen from normal, (low oil, low protein) corn hybrids pollinates nutritionally enhanced corn hybrids, then the specialty traits may not be fully expressed. We followed a testing protocol for comparing nutritionally enhanced corns and normal corn similar to that recommended by Dow AgroSciences.

Table 1 indicates cultural practices and soil types associated with each test. Growing season rainfall and temperatures along with long term averages are shown in Tables 2 and 3 .

Oil, protein, and starch content were determined on a subsample of grain from each plot by near infrared transmittance (NIR) analysis. Grain composition data was reported on a 100% dry matter (0% moisture) basis. Final plant stand and number of stalk lodged plants (stalk breakage below the ear) were recorded at harvest. Plots were harvested by combine and grain yields were adjusted to 15.5% moisture.

RESULTS

Growing Season

Dry soil conditions in May allowed timely planting at both test locations (Table 2). Weather during the 1999 growing season was warmer and drier than normal. Temperatures (Table 3) were above normal throughout the growing season except during August which helped alleviate effects of moisture deficits during the critical grain filling period. Drier than normal weather in August and September promoted rapid grain drydown at both test sites (Tables 2 and 4).

Agronomic Data

Grain yields of the nutritionally enhanced corn hybrids ranged from 164 to 191 Bu/A at Hoytville and 119 to 141 Bu/A at Wooster (Table 4). At Hoytville, most of the Supercede and NutriDense entries produced yields that were not significantly different from the normal corn hybrid, Pioneer 34K77. Yields of most of the Supercede and NutriDense hybrids were comparable. Differences in yield among the specialty and normal hybrids were not significant at Wooster.

Grain drydown at Hoytville was rapid and the grain moisture levels of most entries including the check were below 20% (Table 4). There were significant differences in grain moisture among the nutritionally enhanced hybrids and check hybrid. Grain moisture levels ranged from 13.8 to 20.1 at Hoytville, and 17.3 to 23.8 at Wooster. Differences in harvest population among nutritionally enhanced hybrids and normal hybrid were small at both test sites (Table 4). Stalk lodging averaged 2% or less at both sites (data not shown). Lodging was similar for the nutritionally enhanced hybrids and the normal corn checks.

Grain Quality Data

Grain produced by the NutriDense, Supercede and single cross high oil corn (Seedway 618) was characterized by higher oil content than grain of normal corn hybrid (5.9% vs. 4.2% at Hoytville; 6.0% vs. 4.2% at Wooster) (Table 5). There were significant differences in grain oil content among the nutritionally enhanced hybrids at each location with oil levels ranging from 5.4% to 6.8% at both sites. Grain protein levels of nutritionally enhanced hybrids averaged 2.1 percentage points higher than the normal corn at Hoytville, but only 0.4% higher at Wooster (Table 5). At Hoytville, the nine nutritionally enhanced hybrids exhibited significantly higher grain protein levels than the normal corn, whereas at Wooster, protein levels in the nutritionally enhanced and normal corn grain were generally not significantly different. Leaf firing in plots at Wooster in early September suggests that dry weather may have induced late season N deficiency and contributed to lower grain protein levels. At both locations, there were significant differences in grain protein among the nutritionally enhanced corn hybrids. Starch levels in grain averaged 3.5 percentage points less in nutritionally enhanced corn compared to normal corn (Table 5).

1999 test results suggest that Supercede and NutriDense hybrids can produce grain yields similar to normal corn. The grain oil content of the nutritionally enhanced corn averaged 1.8 percentage points greater than the normal corn check, but protein levels were not consistently higher than normal corn across locations. Stalk quality (as measured by stalk lodging) and grain moisture levels of the Supercede and NutriDense hybrids were comparable to the normal corn hybrid. Since the growing season of 1999 was exceptionally dry, the performance of nutritionally enhanced corns relative to normal corn hybrids may be different under more favorable moisture and temperatures conditions. Additional evaluation is needed to assess the agronomic performance and grain quality characteristics of these nutritionally enhanced corn hybrids across a wider range of environmental conditions.

For more information on the production, marketing, and use of nutritionally enhanced corns, check out the High Oil Corn Production & Marketing Guide Web Site

TC-Blend^®and TopCross^® are registered trademarks of Optimum Quality Grains, L.L.C. Supercede^TM and NutriDense^TM are trademarks of Dow AgroSciences and ExSeed. Genetics, respectively.