Yield response of four hard red spring wheat varieties to six
seeding rates in 1997.
Values were averaged over two locations.
|
Variety
|
Seeding
rate
Seeds per
square foot
|
Variety
Avg.
|
|
14
|
21
|
28
|
35
|
42
|
49
|
|
|
bushels
per acre
|
|
|
Oxen
|
42.6
|
47.4
|
47.5
|
46.7
|
48.9
|
50.6
|
47.3
|
|
Russ
|
41.5
|
47.9
|
51.4
|
52.0
|
51.6
|
49.8
|
49.0
|
|
2375
|
31.7
|
39.2
|
40.9
|
39.9
|
42.6
|
42.7
|
39.5
|
|
Forge
|
38.1
|
43.0
|
43.9
|
45.4
|
44.3
|
44.5
|
43.2
|
|
Seeding rate Avg.
|
38.5
|
44.4
|
45.9
|
46.0
|
46.8
|
47.9
|
44.7
|
Seeding date – Watertown,
May 14 and Brookings, May 20.
Lsd .05 – least significant
difference, a value for comparing treatment differences
at the 0.05 probability level.
Lsd .05 value for
differences between seeding rate averages = 1.8.
Lsd .05 value for
differences between variety averages = 1.5.
Lsd .05
value for differences between any variety and seeding rate = 3.5.
NOTE: Presently, the
recommended seeding rate for spring seeded small grains is
28 seeds per square foot (SPSF) and is
equal to about 1.2 millions seeds per acre.
Variety yield averages had to differ by 1.5 or more and seeding
rate averages by
1.8 bushels per acre or more to be significant. More importantly, there was a
significant variety x seeding rate interaction. Therefore, yield values for any
variety x seeding rate combination had to differ by 3.5 bushels
per acre or more to
be significant. Comparing the 28 to the higher 35, 42, and
49 SPSF seeding
rates by
variety indicated there were no significant yield differences between
the
recommended and the higher seeding rates.
In addition, these trials were
seeded in mid-to-late May a date that one would expect to favor
the highest seeding
rate. In this case, the
higher seeding rates when seeded later than average did not
significantly increase yields.
Source:
Rudd, J., B. Farber, and J. Smolik.
1998. Spring wheat seeding rate
study.
1997 Annual progress report, NE Research
Station, Watertown, SD.
Plant Science
Pamphlet 89: 17.
Robert G. Hall, Extension
Agronomist-Crops
SOUTH
DAKOTA STATE
UNIVERSITY – Plant Science Department, Brookings,
SD
Table 3b. Yield response of
four hard red spring wheat varieties to six seeding
Rates, NE
Research Station, Watertown,
SD, seeded April 29, 1998.
|
Variety
|
Seeding
rate
seeds per
square foot
|
Variety
Avg.
|
|
14
|
21
|
28
|
35
|
42
|
49
|
|
|
bushels
per acre
|
|
|
Oxen
|
41.0
|
45.8
|
45.7
|
43.7
|
43.9
|
48.3
|
44.7
|
|
Russ
|
42.4
|
37.9
|
51.0
|
50.0
|
48.9
|
50.0
|
46.6
|
|
2375
|
32.0
|
41.3
|
37.9
|
38.7
|
37.8
|
39.7
|
37.9
|
|
Forge
|
41.5
|
46.1
|
47.8
|
47.7
|
46.5
|
47.6
|
46.2
|
|
Seeding rate Avg.
|
39.2
|
42.8
|
45.6
|
44.9
|
44.3
|
46.4
|
43.9
|
Lsd .05 – least significant
difference, a value for comparing treatment differences
at the 0.05 probability level.
Lsd .05 value for
differences between seeding rate averages = 3.1.
Lsd .05 value for
differences between variety averages = 2.5.
Lsd .05
value for differences between any variety and seeding rate = 6.1.
NOTE: Variety yield
averages had to differ by 2.5 or more and seeding rate averages by 3.1 bushels
per acre or more to be significant.
More importantly, there was a significant variety x seeding rate interaction. Therefore, yield values for any variety x
seeding rate combination had to differ by 6.1 bushels per acre or more to be
significant. Comparing the 28 to the
higher 35, 42, and 49 SPSF seeding rates by variety indicated there were no
significant yield differences between the recommended and higher seeding rates.
Source:
Rudd, J., B. Farber, R. Devkota, and J.
Smolik. 1999. Spring wheat seeding rate study. 1998 Annual progress report, NE Research
Station, Watertown, SD.
Plant Science Pamphlet 93: 29.
SOUTH DAKOTA STATE UNIVERSITY – Plant
Science, Brookings, SD
Robert
G. Hall, Extension Agronomist-Crops, Tel: 1-605-688-4600
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