Bulletin Number B766
Performance of Commercial Grain Sorghum Hybrids in Indiana, 1997
T. Lemming, G. Ejeta, and J. Axtell
Sorghum has received serious consideration as a grain crop in some Indiana locations.
With adapted hybrids and proper management, sorghum will usually produce higher returns
than either corn or soybeans on certain soil types and low-rainfall areas, especially if
the grain is fed to livestock (see Purdue Extension Publication AY-198). This publication
provides producers, seedsmen, extension educators and others with information on sorghum
hybrid performance.
A total of 28 hybrids from the 6 companies listed in Table 4
were evaluated at four locations in Indiana. One of the earliest sorghum hybrids to be
developed, RS610, and a Purdue cultivar of good agronomic quality and wide adaptation,
P954063, were used in each year's trials as standards against which newer commercial
hybrids can be compared.
LOCATION OF TRIALS
| The four trial locations in 1997 are shown in Figure 1. Location 1
(Tippecanoe County). The trial was at the Purdue University Agronomy Research Center
(ARC), near West Lafayette, on a Chambers silty clay loam soil.
Location 2 (Jennings County). The trial was at the Southeast Purdue Agricultural
Center (SEPAC), near North Vernon, on an Avonburg silt loam soil.
Location 3 (Knox County). The trial was at the Southwest Purdue Agricultural
Center (SWPAC), near Vincennes, on a Ross loam soil.
Location 4 (Dubois County). The trial was at the Southern Indiana Purdue
Agricultural Center (SIPAC), near Dubois, on a Tilsit silt loam soil. |
 |
TRIAL PROCEDURES
Plots. The plots were arranged in a randomized, complete block design with three
replications at each location. Each plot consisted of two rows, 16 feet long, with 30 inch
row spacing.
Planting. The seedbeds were prepared by conventional tillage. Location 1 was
planted with a John Deere Max-emerge planter. Locations 2, 3, and 4 were planted with a
two-row cone planter. The seeding rate was approximately 10 seeds per foot. Plant
population was thinned to six plants per foot shortly after emergence resulting in
approximately 100,000 plants per acre.
Cultural Practices. Ramrod-atrazine pre-plant or pre-emerge herbicide
combination was used for weed control in all locations. Each location was cultivated at
least once and hand weeded as necessary. An optimum soil fertility level was maintained in
order to allow maximum hybrid performance.
Harvest. At the two southern-most locations, heads from all plants in a 10-foot
section of each row of the two-row plot were hand harvested. The Tippecanoe County trial
was harvested with a plot combine. After threshing, grain moisture was recorded and yields
adjusted to 13.5 percent moisture.
Information Recorded. Half-bloom, plant height, and percent bird damage were
recorded during the growing season. Half-bloom is the number of days from planting
until 50 percent of the plants have shed pollen halfway down the head. Physiological
maturity (cessation of dry matter accumulation in the grain) is reached 35-40 days after
half-bloom. Plant height is the average height, in inches, from the soil surface to
the tip of the head at maturity. Bird damage was measured by visual estimation of
the percentage of grain yield lost to bird feeding.
RESULTS
Results of the 1997 performance tests are presented by location in Tables 1 through 3.
General conditions present at each location are given below.
Location 1 (Tippecanoe County) Table 1. The hybrids
were planted on May 17. Rainfall from April through October totaled 18.88 inches. No
lodging or bird damage was observed. A very wet spring contributed to the late planting
date. The growing season was good. The lack of rainfall during July and August did not
reduce yield. Growing degree day (GDD) accumulation totaled 3137. Yields averaged 159
bu/acre (8920 lb.), with the highest yielding hybrid averaging 187 bu/acre (10448 lb.).
This was one of the highest yielding tests in the last 16 years.
Location 2 (Jennings County). The hybrids were planted on May 21. Rainfall from
April through October totaled 25.04 inches. With the wet, early conditions, stand
establishment was very poor, resulting in the abandonment of this location.
Location 3 (Knox County) Table 2. The hybrids were
planted on June 11. Rainfall from April through October totaled 24.56 inches. Extremely
wet conditions in June and July, followed by drought-like conditions in the following
months, stressed the crop. The trial was also damaged by birds, with the average amount of
bird feeding surpassing 20 percent of the potential yield on some hybrids, resulting in
the higher than acceptable variability (CV). Growing degree day (GDD) accumulation totaled
3575. Yields averaged 60 bu/acre (3361 lb.), with the highest yielding hybrid averaging 87
bu/acre (4848 lb.).
Location 4 (Dubois County) Table 3. The hybrids were
planted on June 25. Rainfall from April through October totaled 24.61 inches. A small
amount of bird damage was observed for some of the hybrids. An early wet season
contributed to the very late planting date. Growing degree day (GDD) accumulation totaled
3446. Yields averaged 89 bu/acre (4976 lb.), with the highest yielding hybrid averaging
102 bu/acre (5706 lb.).
An analysis of variance was conducted and the Least Significant Difference (LSD)
computed at the 5 percent level of significance. The LSD indicates how much one entry must
differ from another entry within a location to be reasonably certain that it is a true
difference. If the yield difference between the two hybrids is less than the LSD, then
other factors must be considered in deciding which hybrids to grow, such as days to
flowering. The LSD is given in the same units as the average (i.e. pounds per acre, etc.).
An asterisk (*) beside a yield average on a performance table indicates that the yield is
not significantly different from the highest yield in the table.
The coefficient of variation (CV) was determined for the traits measured. The CV
measures the amount of experimental error relative to the average and indicates how much
error was present. When yields are high, relative to the experimental error, the CV will
be small.
Growing degree day (GDD). A modified 50 scale was used. GDD equals daily mean
minus 50 (below 50 adjust to 50, above 86 adjust to 86). April 1 thru October 31 was
recorded.
Participating companies. The companies participating in the 1997 performance
trials are listed in Table 4.
ACKNOWLEDGMENTS
The Purdue University Sorghum Project acknowledges the assistance of the following
individuals and their staff for help with the field preparation for the 1997 Commercial
Grain Sorghum Performance Trial.
Jim Beaty, Superintendent - ARC
Don Biehle, Superintendent - SEPAC
Melborn Lang, Superintendent - SWPAC
Frank Potts, Superintendent - SIPAC
Credit is given to Philip Hess for writing the computer software, Vartest, used in
preparing the performance tables. Sincere gratitude is also expressed to Bill Foster,
Karen Clymer, Corie Shaner, and Danny Greene for their overall support of the 1997 Sorghum
Yield Testing program.
COPYRIGHT INFORMATION
This information, protected by copyright by the Purdue Research Foundation, is
presented under authority granted the Indiana Agriculture Research Programs to conduct
performance trials, including interpretation of data to the public, and does not imply
endorsement or recommendation by Purdue University. Permission is granted to reproduce
tables only in their entirety provided the source is referenced and the data are not
rearranged, manipulated or reinterpreted. A conspicuous disclaimer which states
"endorsement or recommendation by Purdue University is not implied" must
accompany any information reproduced. Additional copies of this publication are available
to Indiana residents through their local Purdue Cooperative Extension Office or the Media
Distribution Center.