| Bernie White Manager, Variety Evaluations Mississippi State University |
Don Respess County Extension Agent Bolivar County |
| Frank Boykin Operations Manager Black Belt Branch Experiment Station |
Art Smith County Extension Agent Desoto County |
| David Ingram Associate Agronomist Brown Loam Branch Experiment Station |
Charlie Stokes County Extension Agent Monroe County |
| Billy Johnson Senior Research Assistant Coastal Plain Branch Experiment Station |
Clarence Watson Experiment Station Statistician MSU Plant & Soil Sciences |
| Erick Larson Agronomist MSU Plant & Soil Sciences |
|
| Recognition is given to Jessie Selvie and Jerry Nail, research technicians for the Variety Testing Program, for their assistance in packaging, planting, harvesting, and recording plot data. Statistical analyses and computing assistance were given by Eric Hudson, computer programmer, Information Services and User Support and Chip Brooks, student worker, Department of Experimental Statistics. The manuscript was prepared by Jimmie Cooper, administrative secretary for MAFES Research Support Units. It was published by the Office of Agricultural Communications; Division of Agriculture, Forestry, and Veterinary Medicine. | |
This report contains data generated as part of the Mississippi Agricultural and Forestry Experiment Station research program. Joint sponsorship by the organizations listed in Table 2 is gratefully acknowledged.
Commercial and public varieties tested in this research project (trade names, experiment code names, or numbers, etc.) and source of seed are listed in Table 2.
Plots consisted of two 30-inch rows 13.33 feet long, planted on prepared seedbeds. Weeds were controlled by cultivation and/or herbicides. Only herbicides currently registered for use on corn were used in these studies, with strict adherence to all label instructions. Lorsban 15G was donated by Dow Elanco and banded at planting for insect control. Experimental design was a randomized complete block with five replications at each location. Hybrids were divided into two maturity groups based on information provided by the sponsoring companies. Those hybrids that matured in 115 days or less were considered early maturing, while those that required 116 days or more to mature were considered late maturing.
Seed of all entries were supplied by participating companies. All seed were packaged for planting at rates suggested by the participating company and planted with a cone planter. Phosphorus, potassium, and lime were applied according to soil test recommendations. Nitrogen was applied in Areas I and II at 140 to 200 pounds per acre, and plots in Area III received 200 to 300 pounds of N per acre. Plots in Areas I and II were grown in dry land conditions, and plots in Area III were irrigated, if necessary.
Several variables were measured in the 1998 corn hybrid tests:
The least significant difference (LSD) is an estimate of the smallest difference between two varieties that can be declared to be the result of something other than random variation in a particular trial. Consider the following example for a given trial:
| Variety | Yield (bu/A) |
|---|---|
| |
|
| A | 90 |
| B | 85 |
| C | 81 |
| |
|
| LSD | 7 |
The difference between variety A and variety B is 5 bu/A (i.e. 90 - 85 = 5). This difference is smaller than the LSD (7 bu/A). Consequently we would conclude that variety A and variety B have the same yield potential, since we are not able to say that the observed difference did not occur purely due to chance. However, the difference between variety A and variety C is 9 bu/A (i.e. 90 - 81 = 9), which is larger than the LSD (7 bu/A). We would therefore conclude that the yield potential of variety A is superior to that of variety C.
The coefficient of variation (CV) is a measure of the relative precision of a given trial and is used to compare the relative precision of different trials. The CV is generally considered to be an estimate of the amount of unexplained variation in a given trial. This unexplained variation can be the result of variation between plots with respect to soil type, fertility, insects, diseases, moisture stress, etc. In general, the higher the CV the less precise a given trial is.
The coefficient of determination (R2) is another measure of the level of precision in a trial and is also used to compare the relative precision of different trials. The R2 is a measure of the amount of variation that is explained, or accounted for, in a given trial. For example, an R2 value of 90 percent indicates that 90 percent of the observed variation in the trial has been accounted for in the trial, with the remaining 10 percent being unaccounted for. The higher the R2 value, the more precise the trial. The R2 is generally considered to be a better measure of precision than the CV for comparison of different trials.
| Table 1.
Location, number of entries, dates of planting, and dates of harvest for 1998 corn hybrid trials. |
||||
|---|---|---|---|---|
| Location | Maturity1 | No. of entries | Planting date | Harvest date |
| Area I | ||||
| (Hernando) |
Late | 25 | April 2 | August 27 |
| (Aberdeen) |
Early Late |
23 25 |
March 30 | August 28 |
| (Brooksville) |
Early Late |
23 25 |
March 31 | August 20 |
| Area II | ||||
| (Raymond) |
Early Late |
16 14 |
April 3 | September 1 |
| (Newton) |
Early Late |
16 14 |
March 25 Replanted April 19 |
No harvest |
| Area III | ||||
| (Cruger) |
Early Late |
38 28 |
March 28 | August 26 |
| Duke Morgan Farm (Shaw) |
Early Late |
38 28 |
March 27 | August 24 |
| 1Early maturity = 115 days or less; late maturity = 116 days or more. | ||||
| Table 2. Corn hybrid characteristics provided by sponsoring seed companies. | ||||||
|---|---|---|---|---|---|---|
| Company | Hybrid | Planting rate (x 1000) |
Days to maturity |
Grain texture1 |
MDMV resistance2 |
MCDV resistance2 |
| AgraTech Seeds, Inc. 5559 N 500 W McCordsville, IN 46055 |
ATX725 ATX770 967 |
28 32 28 |
113 115 124 |
M M M |
S S R |
S S R |
| AgriPro Seeds, Inc. Southern Business Units Suite 435, 6075 Poplar Ave. Memphis, TN 38119 |
HS9843 AP9828 AP9829IMI AP9707 AP9909 AP9939 |
28 28 28 28 28 28 |
117 118 118 117 120 123 |
H MH MH MH MH M |
S S S S S S |
S S S S S S |
| Asgrow Seed Company P.O. Box 359 Marion, AR 72364 |
RX740 RX760 RX770 RX810 RX813 RX826 RX897 XP8897 RX913 RX938 |
28 28 28 28 28 28 28 28 28 32 |
109 109 109 112 114 114 115 115 117 119 |
-- -- -- -- -- -- -- -- -- -- |
-- -- -- -- -- -- -- -- -- -- |
-- -- -- -- -- -- -- -- -- -- |
| DeKalb Genetics Corp. 3100 Sycamore Road DeKalb, IL 60115 |
DK687 DK683 DK706 DK714 DK626 |
28 28 28 28 28 |
118 118 120 121 112 |
MH MH H H M |
R R MS S S |
R R MS S S |
| Elite Seed, Inc. 969 Cloverleaf Drive Southaven, MS 38671 |
FFR943 FFR726 |
24 28 |
120 113 |
M M |
MR S |
MR S |
| Garst Seed Co. 2369 330th St., Box 500 Slater, IA 50244 |
8220 8222IT 8513IT |
24 24 24 |
119 118 110 |
M M -- |
R S -- |
R S -- |
| Genesis Ag Ltd P.O. Box 21085 Lansing, MI 48909 |
Genesis 1815 Genesis 1818 Genesis 2812 Genesis 2816 |
28 28 24 24 |
115 118 112 118 |
-- -- -- -- |
-- -- -- -- |
-- -- -- -- |
| Douglass W. King Co. 4627 Emil Rd P.O. Box 200320 San Antonio, TX 78220 |
dk5445 dk5570 |
28 28 |
118 119 | -- -- |
-- -- |
-- -- |
| Mycogen Seeds 3600 N. Columbia Plainview, TX 79072 |
8460 | 28 | 118 | M | R | -- |
| Pioneer Hi-Bred International 6767 Old Madison Pike Suite 110 Huntsville, AL 35806 |
3395IR 32K61 3163 3167 3223 3245 3245IR 3394 33R87 33G26 35A19IR |
28 28 24 28 28 28 28 28 24 28 28 |
110 114 119 124 116 115 115 110 112 112 103 |
-- M-H M M -- M -- M -- -- -- |
-- MS MR S -- MS -- S S MR -- |
-- MS MR S -- MR -- S S MR -- |
| Stewart Seeds, Inc. 2230 E., Co. Rd. 300N Greensburg, IN 47240 |
S555 S589 S599 S605 S660 S795 |
28 28 28 26 28 28 |
110 111 111 112 115 118 |
M M H H M M |
-- -- -- -- -- -- |
-- -- -- -- -- -- |
| Terra International, Inc. 600 Fourth Street P.O. Box 6000 Sioux City, IA 51102-6000 |
TR1154 TR1157 TR1167 TR1185 TR1087 TR1088 E1188 |
28 32 32 28 32 32 32 |
115 115 117 118 108 108 118 |
M M M H M M M |
S S R S -- -- -- |
S S R S -- -- -- |
| Terral Seed, Inc. P.O. Box 826 Lake Providence, LA 71254 |
TVX20770 TV2930 TV2090 TV2100 TVX21370 2140 2543 |
28 24 32 28 28 28 32 |
105 118 107 108 111 112 113 |
M M M M MH H MH |
-- R -- -- -- -- MR |
-- R -- -- -- -- MR |
| Tri-State Delta Chemical 6800 Poplar Ave., Suite 100 P.O. Box 382550 Memphis, TN 38183-2550 |
Funk's DG5510A Funk's DG5516 Funk's 4653 |
32 32 32 |
115 118 120 |
H MH MH |
R MR MR |
-- MR MR |
| 1M=Medium; H=Hard. 2MDMV=Maize Dwaraf Mosaic Virus; MCDV=Maize Chlorotic Dwarf Virus (corn stunt; S=Susceptible; R=Resistant; MR=Moderately Resistant; MS=Moderately Susceptible |
||||||
| Table 14. Average grain production, by areas, for early-maturing corn hybrids grown in Mississippi, 1998. | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Hybrid number |
Brand name |
Area I1 | Area II2 | Area III3 | ||||||
| 1998 yield |
2-year avg. |
3-year avg. |
1998 yield |
2-year avg. |
3-year avg. |
1998 yield |
2-year avg. |
3-year avg. |
||
ATX725 |
AgraTech |
-- |
-- |
-- |
-- |
-- |
-- |
162.7 |
-- |
-- |
ATX770 |
AgraTech |
-- |
-- |
-- |
-- |
-- |
-- |
160.9 |
166.5 |
-- |
RX740 |
Asgrow |
-- |
-- |
-- |
-- |
-- |
-- |
162.0 |
-- |
-- |
RX760 |
Asgrow |
-- |
-- |
-- |
-- |
-- |
-- |
175.3 |
-- |
-- |
RX770 |
Asgrow |
-- |
-- |
-- |
-- |
-- |
-- |
150.4 |
-- |
-- |
RX810 |
Asgrow |
-- |
-- |
-- |
-- |
-- |
-- |
170.9 |
-- |
-- |
RX813 |
Asgrow |
-- |
-- |
-- |
-- |
-- |
-- |
179.2 |
170.5 |
-- |
RX826 |
Asgrow |
-- |
-- |
-- |
-- |
-- |
-- |
160.9 |
-- |
-- |
RX897 |
Asgrow |
-- |
-- |
-- |
-- |
-- |
-- |
183.2 |
178.3 |
173.3 |
XP8897 |
Asgrow |
-- |
-- |
-- |
-- |
-- |
-- |
171.8 |
-- |
-- |
DK626 |
DeKalb |
-- |
-- |
-- |
114.9 |
-- |
-- |
175.2 |
172.1 |
-- |
FFR726 |
Elite |
76.9 |
-- |
-- |
-- |
-- |
-- |
183.2 |
-- |
-- |
DG 5510A |
Funk's |
98.9 |
92.1 |
85.7 |
129.7 |
143.1 |
-- |
192.2 |
181.8 |
177.3 |
8513IT |
Garst |
72.4 |
-- |
-- |
-- |
-- |
-- |
169.1 |
-- |
-- |
Genesis 1815 |
Genesis |
-- |
-- |
-- |
-- |
-- |
-- |
160.6 |
-- |
-- |
Genesis 2812 |
Genesis |
-- |
-- |
-- |
-- |
-- |
-- |
164.8 |
-- |
-- |
3395IR |
Pioneer |
78.7 |
-- |
-- |
-- |
-- |
-- |
159.4 |
-- |
-- |
32K61 |
Pioneer |
101.9 |
91.2 |
-- |
126.7 |
158.2 |
-- |
178.1 |
181.9 |
-- |
3245 |
Pioneer |
-- |
-- |
-- |
122.5 |
139.5 |
117.4 |
200.7 |
189.9 |
186.1 |
3245IR |
Pioneer |
-- |
-- |
-- |
89.4 |
-- |
-- |
163.8 |
-- |
-- |
3394 |
Pioneer |
78.5 |
85.6 |
83.5 |
-- |
-- |
-- |
166.3 |
-- |
-- |
33R87 |
Pioneer |
74.2 |
-- |
-- |
104.0 |
-- |
-- |
160.9 |
-- |
-- |
35A19IR4 |
Pioneer |
-- |
-- |
-- |
-- |
-- |
-- |
-- |
-- |
-- |
33G26 |
Pioneer |
107.1 |
-- |
-- |
-- |
-- |
-- |
172.0 |
-- |
-- |
S555 |
Stewart |
90.9 |
-- |
-- |
-- |
-- |
-- |
176.5 |
-- |
-- |
S589 |
Stewart |
76.2 |
-- |
-- |
-- |
-- |
-- |
161.2 |
-- |
-- |
S599 |
Stewart |
77.5 |
-- |
-- |
-- |
-- |
-- |
167.2 |
-- |
-- |
S605 |
Stewart |
79.2 |
-- |
-- |
-- |
-- |
-- |
159.5 |
-- |
-- |
S660 |
Stewart |
95.3 |
-- |
-- |
-- |
-- |
-- |
176.3 |
-- |
-- |
TR1154 |
Terra |
78.9 |
75.6 |
80.1 |
123.6 |
137.1 |
113.3 |
184.5 |
174.5 |
175.8 |
TR1157 |
Terra |
76.1 |
77.6 |
79.5 |
106.1 |
135.6 |
112.7 |
196.5 |
188.5 |
182.2 |
TR1087 |
Terra |
79.5 |
84.3 |
-- |
97.2 |
123.8 |
-- |
186.9 |
182.7 |
-- |
TR1088 |
Terra |
86.2 |
-- |
-- |
102.7 |
-- |
-- |
172.5 |
-- |
-- |
TVX20770 |
Terral |
72.8 |
75.1 |
-- |
93.5 |
-- |
-- |
169.1 |
-- |
-- |
TV2090 |
Terral |
69.2 |
70.3 |
-- |
98.0 |
-- |
-- |
169.0 |
-- |
-- |
TV2100 |
Terral |
75.9 |
77.7 |
-- |
81.8 |
121.3 |
-- |
172.3 |
174.3 |
-- |
TVX21370 |
Terral |
76.7 |
-- |
-- |
97.4 |
-- |
-- |
144.9 |
147.3 |
-- |
TV2140 |
Terral |
72.8 |
-- |
-- |
114.8 |
143.2 |
-- |
182.9 |
181.6 |
-- |
TV2543 |
Terral |
91.3 |
-- |
-- |
100.0 |
-- |
-- |
171.3 |
-- |
-- |
Overall Mean |
80.9 |
80.4 |
82.2 |
106.4 |
137.7 |
114.5 |
171.7 |
176.2 |
178.9 |
|
LSD (.10) |
9.7 |
6.5 |
6.3 |
12.0 |
10.0 |
9.2 |
18.5 |
10.9 |
8.2 |
|
Error degrees of freedom |
128 |
108 |
63 |
60 |
84 |
32 |
290 |
190 |
95 |
|
CV (%) |
14.2 |
14.6 |
16.9 |
10.7 |
11.9 |
15.0 |
14.5 |
11.7 |
10.7 |
|
R2 % |
75 |
67 |
76 |
72 |
87 |
94 |
55 |
62 |
67 |
|
| 1Average of Aberdeen and Brooksville. 2Average of Newton and Raymond. 3Two-year average = Cruger, Shaw, and MSU; 3-year average = Cruger, Shaw, MSU, and Stoneville. 4Planted at Hernando Only. |
||||||||||
| Table 15. Average grain production, by areas, for late-maturing corn hybrids grown in Mississippi, 1998. | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Hybrid number |
Brand name |
Area I1 | Area II2 | Area III3 | ||||||
| 1998 yield |
2-year avg. |
3-year avg. |
1998 yield |
2-year avg. |
3-year avg. |
1998 yield |
2-year avg. |
3-year avg. |
||
967 |
AgraTech |
-- |
-- |
-- |
-- |
-- |
-- |
153.6 |
-- |
-- |
HS9843 |
AgriPro |
88.0 |
106.2 |
97.7 |
107.3 |
-- |
-- |
167.2 |
164.6 |
143.8 |
AP9828 |
AgriPro |
77.7 |
-- |
-- |
109.6 |
-- |
-- |
173.7 |
-- |
-- |
AP9828IMI |
AgriPro |
76.0 |
-- |
-- |
104.6 |
-- |
-- |
166.7 |
-- |
-- |
AP9707 |
AgriPro |
80.2 |
-- |
-- |
105.4 |
-- |
-- |
179.6 |
-- |
-- |
AP9909 |
AgriPro |
86.9 |
95.0 |
-- |
-- |
-- |
-- |
155.8 |
152.9 |
-- |
AP9939 |
AgriPro |
87.1 |
-- |
-- |
-- |
-- |
-- |
168.1 |
-- |
-- |
RX913 |
Asgrow |
75.6 |
-- |
-- |
-- |
-- |
-- |
168.0 |
-- |
-- |
RX938 |
Asgrow |
-- |
-- |
-- |
-- |
-- |
-- |
154.1 |
163.7 |
141.5 |
DK687 |
DeKalb |
83.5 |
108.7 |
-- |
110.3 |
131.6 |
-- |
171.3 |
164.1 |
-- |
DK683 |
DeKalb |
73.9 |
96.3 |
87.1 |
96.2 |
135.1 |
-- |
170.7 |
161.8 |
145.0 |
DK706 |
DeKalb |
77.4 |
96.2 |
85.4 |
99.6 |
133.7 |
107.3 |
141.9 |
141.4 |
123.7 |
DK714 |
DeKalb |
-- |
-- |
-- |
-- |
-- |
-- |
171.8 |
168.2 |
-- |
FFR943 |
Elite |
71.5 |
-- |
-- |
-- |
-- |
-- |
172.7 |
-- |
-- |
DG5516 |
Funk's |
-- |
-- |
-- |
-- |
-- |
-- |
194.0 |
-- |
-- |
4653 |
Funk's |
64.0 |
-- |
-- |
-- |
-- |
-- |
-- |
-- |
-- |
8220 |
Garst |
78.7 |
-- |
-- |
-- |
-- |
-- |
138.5 |
-- |
-- |
8222IT |
Garst |
73.8 |
-- |
-- |
-- |
-- |
-- |
146.8 |
-- |
-- |
Genesis 1818 |
Genesis |
-- |
-- |
-- |
-- |
-- |
-- |
149.5 |
-- |
-- |
Genesis 2816 |
Genesis |
-- |
-- |
-- |
-- |
-- |
-- |
136.1 |
-- |
-- |
dk 5445 |
Douglass King |
86.6 |
-- |
-- |
-- |
-- |
-- |
-- |
-- |
-- |
dk 5570 |
Douglass King |
88.7 |
-- |
-- |
-- |
-- |
-- |
-- |
-- |
-- |
8460 |
Mycogen |
80.1 |
102.0 |
88.9 |
-- |
-- |
-- |
176.2 |
160.9 |
135.8 |
3163 |
Pioneer |
85.3 |
109.8 |
95.9 |
113.1 |
138.6 |
115.2 |
178.1 |
170.1 |
147.8 |
3167 |
Pioneer |
91.0 |
103.5 |
95.2 |
106.5 |
134.7 |
109.3 |
173.1 |
173.1 |
146.1 |
3223 |
Pioneer |
96.8 |
112.5 |
101.4 |
117.6 |
146.5 |
-- |
184.7 |
182.6 |
-- |
S795 |
Stewart |
85.8 |
-- |
-- |
-- |
-- |
-- |
169.2 |
-- |
-- |
TR1167 |
Terra |
88.2 |
104.1 |
94.1 |
110.8 |
136.1 |
-- |
188.3 |
171.6 |
148.0 |
TR1185 |
Terra |
78.7 |
97.9 |
87.1 |
103.4 |
126.0 |
-- |
173.4 |
164.4 |
138.9 |
E1188 |
Terra |
73.2 |
-- |
-- |
96.6 |
-- |
-- |
187.7 |
-- |
-- |
TV2930 |
Terral |
76.0 |
-- |
-- |
109.2 |
-- |
-- |
160.3 |
158.2 |
134.2 |
Overall Mean |
78.4 |
102.9 |
92.5 |
106.4 |
135.2 |
110.6 |
166.6 |
163.9 |
140.5 |
|
LSD (.10) |
9.2 |
6.7 |
5.6 |
14.6 |
7.7 |
6.3 |
17.6 |
11.5 |
9.9 |
|
Error degrees of freedom |
300 |
240 |
288 |
52 |
84 |
32 |
211 |
204 |
258 |
|
CV (%) |
19.5 |
15.3 |
17.5 |
12.9 |
9.3 |
10.7 |
14.2 |
13.4 |
16.5 |
|