Ohio State University Extension Fact Sheet

Horticulture and Crop Science

2001 Fyffe Court, Columbus, OH 43210-1096

1998 High Oil Corn TC Blend® Performance Tests

AGF-136-98

Peter R. Thomison
Allen B. Geyer

High oil corn acreage in the United States has increased from less than 50,000 acres in 1992 to more than one million acres in 1998. High oil corn contains 1-1/2 to 2 times more oil as well as higher quality proteins than normal yellow dent corn. It is attractive as a livestock feed because it has greater energy value than normal yellow dent corn and can replace more expensive dietary sources of fats and proteins. Contract production of high oil grain may offer corn growers higher profits through premiums. The TopCross® grain production system licensed by Optimum Quality Grains, L.L.C. (hereafter referred to as Optimum) is rapidly gaining popularity as the preferred method of producing high oil corn. The TopCross system minimizes the yield disadvantage associated with conventional high oil corn hybrids while enhancing grain nutrient composition.

The TopCross high oil grain production system involves planting a blend (TC Blend® seed corn) of two types of corn. One type, representing 90 to 92% of the seed in the blend, is a hybrid that is designated as the "grain parent." The second type, representing 8 to 10% of the seed, is a special "pollinator." The grain parent is a male sterile (produces no pollen) version of an elite hybrid that may be in commercial production. The pollinator is a special line, available from Optimum and licensed to seed companies, that sheds pollen within a TopCross grain production field. The pollen shed from these pollinator plants contain special genes that cause a kernel to produce a much larger than average embryo. Since most of the oil and essential amino acids are in the embryo, the oil, and thus the energy level, and protein quality of the grain produced by fertilization with these pollinators is enhanced. Pollinator plants contribute little to overall grain yield. Their function is to provide pollen to the male sterile grain parent.

In response to increasing interest in high oil corn among growers and seed companies, we conducted performance tests in 1998 at two Ohio locations comparing TC Blend seed products used in TopCross high oil grain production. The major objective of these tests was to evaluate the agronomic performance and grain quality characteristics (i.e. oil content) of TC Blends that are adapted to Ohio growing conditions and commercially available to corn growers.

The high oil corn tests were established at the Ohio State University (OSU) - Ohio Agricultural Research and Development Research (OARDC) Western Branch Research Farm near South Charleston (S. Charleston) in southwest Ohio and the OSU-OARDC Northwest Branch Research Farm near Hoytville in northwest Ohio. Sixteen high oil TC Blends representing nine seed companies were planted at each site. The male fertile grain parents (DeKalb 595, Pfister 3049, and Pioneer brand 34K77) of three of the TC Blend entries were included in the trials as checks. Contributors of seed for the 1998 tests are listed in Table 1.

Table 1. Sources of high oil TC Blend Seed products and hybrids entered in the 1997 High Oil Corn TC Blend Performance Tests.

Data from the High Oil TC Blend Performance 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 high oil TC Blends is difficult due to isolation requirements. If pollen from normal, low oil corn hybrids pollinates male sterile hybrids in the blend, then the high oil trait is not expressed. We followed a testing protocol for comparing multiple pollinators and TC Blends that was recommended by Optimum. A similar procedure was used in The Ohio State University field studies from 1995 to 1997 to compare high oil TC Blends and their normal counterparts. Since three different pollinators were used in the TC Blends submitted for evaluations, it was necessary to group or block entries by pollinator to minimize cross pollination. The corn hybrid checks were isolated from TC Blends by at least 40 rows planted to TC Blends to ensure minimum pollen contamination by normal corns. TC Blend blocks with different pollinators were separated by 24 border rows (12 adjacent rows of each pollinator type) to minimize cross pollination.

Table 2 indicates cultural practices and soil types associated with each test. Growing season rainfall and temperatures along with long term averages are shown in Table 3 and 4.

Table 2. Test plot locations, cultural practices and soil types for the 1987 High Oil Com TC Blend® Performance Tests, 1998.

Table 3. Precipitation for 1998 High Oil Corn TC Blend® Performance Test sites.

Table 4. Air temperatures for 1998 High Oil Com TC Blend® Performance Test sites.

The number of plants shedding pollen was recorded at S. Charleston to determine the percentage of pollinator plants in each TC Blend. Data were collected for percent root lodged plants at S. Charleston following severe thunderstorms accompanied by strong winds in July (Tables 5 and 6). Shortly before harvest, ten ears were randomly selected from plants in a 50-foot length of row in the center of each plot. These ears were shelled and a subsample of grain from each plot was submitted to the Optimum® Grains Laboratory (Urbandale, IA) for grain nutrient composition. Oil, protein, and starch content were determined by near infrared transmittance (NIT) analysis. Metabolizable energy (M. E.) and lysine were estimated by calculation. Final plant stand, number of stalk lodged plants (stalk breakage below the ear), and barren (including nubbin ears) plants were recorded at harvest. Plots were harvested by combine and grain yields were adjusted to 15.5% moisture.

Results

Growing Season

Cooler and wetter soil conditions in early May resulted in later planting at Hoytville than at S. Charleston (Tables 3-4). Although weather throughout the growing season was warmer and drier than normal at S. Charleston, there was no evidence of drought stress. Temperatures were also above normal at Hoytville but precipitation was above average especially during grain fill in August. Strong winds associated with thunderstorms in mid July caused varying degrees of root lodging at S. Charleston. Warmer and drier than normal weather in September facilitated rapid grain drydown at both test sites (Tables 3-4).

Agronomic Data

Grain yields of TC Blends ranged from 143 to 167 Bu/A at Hoytville (Table 5) and 188 to 210 Bu/A at S. Charleston (Table 6). TC Blend yields averaged about 4% (8 Bu/A) and 10%(18 Bu/A) less than yields of the checks at S. Charleston and Hoytville, respectively. At Hoytville, the top yielding check hybrid, Pfister 3049, yielded significantly more than the TC Blends; but yields of several TC Blend entries did not differ significantly from the other two checks. Over half the TC Blend entries produced yields that were not significantly different from the top yielding TC Blend. At S. Charleston, yields of seven TC Blends (AgriGold A6460TC8, Beck 5405TC, Beck X5727TC, DeKalb CR8659, LG Seeds 2583TC, LG Seeds 2604TC, and Pfister SK3049-19) were not significantly different from the top yielding check hybrid Pfister 3049. The grain yields of most TC Blends were not significantly different from the top yielding TC Blend.

Table 5. Agronomic performance and grain quality data from the High Oil Corn TC Blend® Performance Test at Hoytville, Ohio, 1998.

Table 6. Agronomic performance and grain quality data from the High Oil Corn TC Blend® Performance Test at South Charleston, Ohio, 1998.

Grain drydown at both test locations was rapid and the grain moisture of most TC Blends was below 20%. There were significant differences in grain moisture among the TC Blends and check hybrids. Grain moisture levels of TC Blends ranged from 14.8 to 21.7 at Hoytville and 13.7 to 18.5 at S. Charleston.

At S. Charleston differences in harvest population between TC Blends and normal hybrids were negligible but at Hoytville final stands averaged about 4 % lower for TC Blends than for the normal hybrids. This difference may have contributed to lower yields for some TC Blends. The percentage of plants shedding pollen during anthesis at S. Charleston averaged 6 to 7% in the TC Blends.

Stalk lodging averaged 3% or less at both sites (data not shown). Lodging was similar for TC Blends and normal corn checks. Root lodging at S. Charleston ranged from 3 to 16 % and was significantly greater in most TC Blends than in two of the check hybrids (Table 6). One of the checks showed high levels of root lodging similar to that of the TC Blends. Most root lodging was associated with the pollinator plants in the TC Blends. There did not appear to be a relationship between percent root lodged plants and grain yield.

Grain Quality Data

TopCross grain produced by the TC Blends was characterized by higher oil content than grain of normal corn hybrids (7.1% vs. 4.6% at Hoytville; 7.2% vs. 4.0% at S. Charleston). There were significant differences in grain oil content among the 16 TC Blends at each location with oil levels ranging from 6.5% to 7.8% at Hoytville and 5.8% to 8.0% at S. Charleston. Estimates of metabolizable energy for non-ruminants were consistently greater in TopCross grain than in grain of normal hybrids. Grain protein levels of TopCross and normal grain were comparable at Hoytville but protein levels were higher in grain of normal corn than in TopCross grain at S. Charleston. Estimates of lysine content were higher in TopCross grain than in grain of normal corn hybrids at both locations. Starch levels were lower in TopCross grain compared to grain of normal corn.

Summary

1998 test results indicate that TC Blends are available with grain yield potential similar to normal corn hybrids. However there were significant differences in yield and grain oil content among the various TC Blends evaluated. The oil content of TopCross grain was 2.5 to 3.3 percentage points higher than in normal corn checks. Stalk quality (as measured by stalk lodging) of TC Blends was comparable to normal corn hybrids.

TopCross®, TC-Blend® and Optimum® are registered trademarks of Optimum Quality Grains, L.L.C.