INTENSIVE HARD RED SPRING WHEAT MANAGEMENT STUDY
Robert G. Hall, Kevin K. Kirby, and Glenda
Piechowski
INTRODUCTION
Some growers are changing to
more intensive management in hopes of increasing the yield and quality of their
hard red spring wheat. Two input factors
they have increased are (1) seeding rate and (2) level of nitrogen fertility.
Purpose: Evaluate the response of hard red spring
wheat to (1) high seeding rates and (2) to a level of nitrogen fertility equal
to a common yield goal for the local area and an elevated yield goal of 100
bushels per acre.
MATERIALS & METHODS
This study was conducted at
two locations from 2003 to 2004 (Table 1).
The South Shore study was located on the Orrin Korth farm on Hwy-77 adjacent to the southern border of the
NE Research Farm. The Warner study was
located on the Allen and Inel Ryckman
Farm, five miles east and a mile south of Warner, SD. Common N-yield goals (NYG) included 50 and 64
bu/ac at Warner and South Shore,
respectively. A high 100 bu/ac yield goal was used at both sites. Varieties included Forge, Oxen, Walworth, and
the experimental line SD3623. Seeding
rates included a recommended 1X rate of 28 pure-live-seeds (PLS)/ft2,
an intermediate 1.5X rate (42 PLS), and a high 2X rate (56 PLS).
The common and high NYG
levels were calculated using the soil test results and recommendations
indicated in Table 1. A total of 250 of N (soil test N + applied N) is
recommended for a 100 bu/ac NYG. Soil tests at South Shore
and Warner indicated available nitrogen (N) levels of 161 and 65 lb/ac,
respectively. At South Shore,
no additional N was applied to attain the 64 bu/ac NYG
while an additional 60 pounds of N was added to attain the 50 bu/ac NYG at Warner.
The test results also indicated an additional 90 lb/ac of N was needed
at South Shore and 185 lb/ac of N was needed at Warner
to attain the 100 bu/ac NYG at both locations. Additional fertility needed to attain a given
NYG was applied just before the planting. Nitrogen fertilizer was supplied as
35-18-0 and urea (46-0-0) and P was supplied as diammonium
phosphate (18-46-0).
Plots were 5 feet wide by 20
feet long and were seeded with a small plot cone-drill. The experimental design at both locations was
a stratified split-split plot design. The
design factors included variety, seeding rate, and level of N-fertility as
defined by yield goal. There were 54
total plots per location (4 varieties or experimental lines x 2 NYG levels x 3
seeding rates x 3 blocks = 72). Seeding
was accomplished by the cone-drill in two stages. First, any additional fertilizer was applied;
then plots were then seeded.
Fungicide treatments included
Tilt, applied at 2.0 oz/ac at first leaf and again at flag leaf emergence; and Folicur, applied at 4.0 oz/ac at the initial flowering
stage (Feekes, 10.51). Tilt was applied at Warner on May 14 and June
11; and at South Shore on May 19 and June11, at the first
leaf and flag emergence stages, respectively.
Folicur was applied during flowering at Warner
on June 20 and South
Shore on June 24. Weed control included Puma (.5 pt/ac) and Bronate (1 pt/ac) applied by label instructions.
Plots were harvested with a Wintersteiger Elite small plot combine. Prior to combining, two 4-foot sections of
row were randomly selected within each plot.
Plants within these two sections were pulled by hand and grouped into a
composite sample. The samples were then used
to determine what effects variety, seeding rate, and NYG level have on the density
variables spikes (heads)/ft2, seeds/spike, seeds/lb, and spikes/seed
kernel. The first three density variables
indicate if the treatments influence yield by affecting spikes/ft2, seeds/spike,
and seeds/lb (seed size). The last
variable spikes/seed kernel was calculated to determine if treatments affected
the number of spikes produced/seed kernel planted. The number of spikes and
seeds (seed counter) in each sample were counted. Spikes/ft2, spikes/seed kernel, seeds/spike
and seeds/lb (seed size) was then calculated.
Each sample and combined plot yield was added together to obtain the final
plot yield. Significant treatment
effects and interactions (.05 level of probability) were identified using mixed
analysis procedures from the Statistical Analysis System. Temperature and rainfall data is listed for
the nearest weather station in Table 2.
Table 1. Materials & methods used at both test
locations in 2003 and 2004.
|
Materials
|
Location
|
|
South Shore
|
Warner
|
|
Year:
|
2003 2004
|
|
Variety
(maturity, days):
|
Forge (-1), Oxen
(2), Walworth (2), SD3623 (2)
|
|
Seeding
rate/ft2:
|
1X (28 pure-live-seeds,
PLS), 1.5X (42PLS), 2X (56PLS)
|
|
Seeding
date: 2003/2004
|
April 15/April 12
|
April 8/April 2
|
|
Yield
goal bu/ac:
Common
|
64
|
50
|
|
High
|
100
|
100
|
|
Fungicides
applied (fl oz/ac):
|
(1) 2 oz Tilt, 1st
leaf
(2) 2 oz Tilt, flag
leaf emergence
(3) 4 oz Folicur, initial flowering
|
|
|
|
|
|
Herbicides
applied (pt/ac):
|
Puma (0.5) & Bronate
(1.0)
|
|
|
|
Table
2. Temperature and rainfall levels for
2003 growing season starting April 1.
|
Reporting
date
|
Location
|
|
South Shore – N.E. Research Farm
|
Aberdeen Airport
|
|
Avg. Temp. - o F.
|
Total Rainfall. – in.
|
Avg. Temp. - o
F.
|
Total Rainfall – in.
|
|
Avg.
|
DFN*
|
Avg.
|
DFN*
|
Avg.
|
DFN*
|
Avg.
|
DFN*
|
|
April 27
|
44.4
|
+ 1.4
|
1.40
|
- 0.35
|
43
|
- 9
|
1.34
|
- 0.40
|
|
June 1
|
53.0
|
+ 2.8
|
5.04
|
+ 0.35
|
53
|
- 9
|
4.19
|
- 0.26
|
|
June 29
|
62.8
|
- 2.4
|
6.22
|
- 2.24
|
80
|
+ 9
|
10.76
|
+ 3.35
|
|
July 27
|
69.6
|
- 0.8
|
7.95
|
- 1.67
|
71
|
- 3
|
12.68
|
+ 2.74
|
|
Aug. 31
|
70.4
|
+ 2.4
|
9.56
|
- 4.78
|
72
|
0
|
14.33
|
+ 1.94
|
* Departure from normal –
DFN. South Dakota Weekly Weather Crop Report,
SDASS.
RESULTS & DISCUSSION
This study was conducted
under conditions where four varieties, three seeding rates, and two N-yield
goals were imposed. Fungicides were
applied to limit plant disease.
In general, the growing
season weather at South
Shore was near average in
temperature but below average in rainfall.
In contrast, at Warner, the weather was below average in temperature and
near average in rainfall for April to May.
In June temperatures rose above average then cooled down below average
in July. During both June and July
rainfall totals were well above average.
At Warner, this combination of a cool spring and below average
temperatures in July along with above average rainfall in June and July closely
approximated an ideal growing season for small grain compared the hotter and
drier climate at South
Shore. A grain yield average of 60 and 39 bu/ac and test weight average of 60 and 56 lb/bu at Warner and South
Shore, respectively, is
indicative of the better small growing season at Warner.
At South Shore
(Tables 3a and 4a), there were significant main effects for variety (V),
seeding rate (SR), and N-yield goal (NYG); and for the two-way effect for V x
SR. Likewise, at Warner (Tables 3b and
4b), there were significant were main effects for V, SR, and NYG; and the
two-way effects for V x SR and V x NYG.
Variety Performance Variables – Main effects:
Variety effect: At South Shore
(Table 3a), variety did not affect yield and lodging, but did affect test weight,
protein, or plant height. SD3623
exhibited the highest test weight. The
protein content for Oxen and Walworth were high while SD3623 was low.
At Warner (Table 3b), only
yield, plant height, and lodging were significantly affected by variety. Oxen produced the highest while Forge
produced the lowest yield. SD3623 was
the tallest variety while Walworth and Oxen were the shortest. SD3623 exhibited
the most while Oxen exhibited the least lodging.
On average, the grain yield
at South Shore where it was drier was about 20 bu less than at Warner.
This lack of a variety effect on yield at South Shore
was likely the result of limited growing season rainfall. This lack of moisture likely caused the
yielding ability of the varieties to be reduced so variety yield differences
were not detected.
Seeding rate (SR) effect: At South Shore (Table 3a), all the variety
performance variables were affected by SR.
Both the 1X and the 1.5X SR yielded more, was higher in test weight, and
was taller than if seeded at the 2X rate. In contrast, The 2X SR produced higher protein
values compared to the other rates.
However, the 2X SR produced the most while the 1X rate produced the
least lodging.
Table
3a. Main effect means for variety,
seeding rate, and N-yield goal and their effect
on HR spring wheat performance variables at South Shore, SD.
|
Treatment Effects
|
Variety
performance variables
|
|
Yield
bu/ac
|
Test Wt.
lb/bu
|
Protein
%
|
Height
inch
|
Lodging
%
|
|
Year (Y):
|
|
|
|
|
|
|
2003
|
40a*
|
56a
|
16.2a
|
31b
|
2 a
|
|
2004
|
69b
|
60b
|
13.9b
|
39a
|
3 b
|
|
Variety (V):
|
|
|
|
|
|
|
Forge
|
54 b
|
58 b
|
15.0 b
|
36
|
2 a
|
|
Oxen
|
52 b
|
56 c
|
15.2 ab
|
32
|
2 a
|
|
Walworth
|
51 b
|
57 bc
|
15.5 a
|
34
|
2 a
|
|
SD3623
|
59 a
|
60 a
|
14.6 c
|
37
|
3 b
|
|
Seeding rate (SR):
|
NS
|
|
|
|
|
|
1X (28) - recommended
|
55
|
58a
|
14.8 c
|
35 a
|
2 a
|
|
1.5X
(42) - intermediate
|
56
|
58a
|
15.0 b
|
35 a
|
2 a
|
|
2X (56) - high
|
52
|
57b
|
15.3 a
|
34 b
|
3 b
|
|
N-yield goal (YG) :
|
NS
|
NS
|
|
NS
|
NS
|
|
64 bu/ac
|
55
|
58
|
14.9 b
|
35
|
2
|
|
100 bu/ac
|
54
|
58
|
15.2 a
|
35
|
2
|
*Values followed by the same
letter in bold type do not differ significantly (.05 level).
Table
3b. Two-way effect means for year,
variety, seeding rate, and N-yield goal and
their effect on spring wheat
performance variables at South Shore,
SD.
|
Treatment Effects
|
Variety
performance variables
|
|
Yield
bu/ac
|
Test Wt.
lb/bu
|
Protein
%
|
Height
inch
|
Lodging
%
|
|
|
2003
|
2004
|
2003
|
2004
|
2003
|
2004
|
2003
|
2004
|
2003
|
2004
|
|
V x Y:
|
|
|
|
|
NS
|
NS
|
NS
|
NS
|
|
|
|
Forge
|
37a*
|
71b
|
55b
|
61a
|
-
|
-
|
-
|
-
|
2.2a
|
1.9a
|
|
Oxen
|
42a
|
63c
|
55b
|
58c
|
-
|
-
|
-
|
-
|
1.8a
|
2.4a
|
|
Walworth
|
38a
|
65c
|
55b
|
59b
|
-
|
-
|
-
|
-
|
1.9a
|
3.5c
|
|
SD3623
|
41a
|
77a
|
58a
|
61a
|
-
|
-
|
-
|
-
|
2.3a
|
2.5b
|
|
SR x Y:
|
|
|
NS
|
NS
|
|
|
|
|
NS
|
NS
|
|
1X (28)
|
41a
|
69a
|
57a
|
60
|
15.9b
|
13.8a
|
31a
|
40a
|
-
|
-
|
|
1.5X (42)
|
42a
|
70a
|
56b
|
60
|
16.1b
|
13.9a
|
31a
|
39a
|
-
|
-
|
|
2X (56)
|
36b
|
68a
|
55c
|
60
|
16.7a
|
13.9a
|
29b
|
39a
|
-
|
-
|
|
YG x Y:
|
|
NS
|
NS
|
NS
|
|
|
NS
|
NS
|
-
|
NS
|
|
64 bu/ac
|
-
|
|
-
|
-
|
15.9b
|
13.8a
|
-
|
-
|
-
|
-
|
|
100 bu/ac
|
-
|
|
-
|
-
|
16.5a
|
13.9a
|
-
|
-
|
-
|
-
|
|
|
|
|
|
|
|
|
|
|
|
|
*Values followed by the same
letter in bold type do not differ significantly (.05 level).
Table
3c. Three-way effect means for year,
variety, seeding rate, and N-yield goal and
their effect on spring wheat
performance variables at South Shore,
SD.
|
Treatment Effects
|
Variety
performance variables
|
|
Test Wt. lb/bu
|
Protein %
|
Lodging %
|
|
SR x V x Y:
|
2003
|
2004
|
2003
|
2004
|
2003
|
2004
|
|
1X – Forge
|
57 b*
|
61 a
|
15.8 e
|
14.0 abc
|
1.83 a
|
1.83 a
|
|
Oxen
|
56 c
|
57 e
|
16.1 cde
|
13.6 c
|
1.67 a
|
1.83 a
|
|
Walworth
|
55 d
|
60 b
|
16.7 ab
|
13.9 bc
|
1.67 a
|
2.33 abc
|
|
SD3623
|
58 a
|
61 a
|
15.2 f
|
13.5 c
|
2.0 ab
|
2.17 abc
|
|
1.5X – Forge
|
56 c
|
61 a
|
15.9 de
|
14.0 abc
|
2.17 ab
|
2.00 ab
|
|
Oxen
|
55 d
|
58 d
|
16.4 bc
|
13.9 bc
|
1.83 a
|
2.33 abc
|
|
Walworth
|
55 d
|
59 c
|
16.5 bc
|
14.2 ab
|
2.0 ab
|
3.67 cd
|
|
SD3623
|
58 a
|
61 a
|
15.4 ef
|
13.5 c
|
2.17 ab
|
2.17 abc
|
|
2X – Forge
|
53 f
|
61 a
|
16.4 bc
|
13.9 bc
|
2.67 ab
|
2.00 ab
|
|
Oxen
|
54 d
|
58 d
|
17.1 a
|
13.9 bc
|
1.83 a
|
3.00 bc
|
|
Walworth
|
56 c
|
60 b
|
17.0 a
|
14.5 a
|
2.17 ab
|
4.50 d
|
|
SD3623
|
57 b
|
61 a
|
16.3 bcd
|
13.5 c
|
2.83 b
|
3.17 c
|
*Values followed by the same
letter in bold type do not differ significantly (.05 level).
Table
4a. Main effect means for variety,
seeding rate, and N-yield goal and their effect
on HR spring wheat performance
variables at Warner, SD.
|
Treatment Effects
|
Variety
performance variables
|
|
Yield
bu/ac
|
Test Wt.
lb/bu
|
Protein
%
|
Height
inch
|
Lodging
%
|
|
Year (Y):
|
|
NS
|
|
|
NS
|
|
2003
|
60a*
|
61
|
15.6a
|
35 b
|
3.0
|
|
2004
|
65b
|
60
|
13.4b
|
38 a
|
3.0
|
|
Variety (V):
|
|
NS
|
|
|
NS
|
|
Forge
|
59c
|
61
|
14.6ab
|
37b
|
2.7a
|
|
Oxen
|
65a
|
60
|
14.4ab
|
35c
|
2.8ab
|
|
Walworth
|
62b
|
61
|
14.8a
|
35c
|
3.4c
|
|
SD3623
|
65a
|
61
|
14.0b
|
40a
|
3.2b
|
|
Seeding rate (SR):
|
NS
|
NS
|
NS
|
|
|
|
1X (28) - recommended
|
55
|
61
|
14.5
|
37 a
|
2.6a
|
|
1.5X (42) - intermediate
|
56
|
61
|
14.5
|
37 a
|
2.9b
|
|
2X (56) - high
|
52
|
60
|
14.4
|
36 b
|
3.5c
|
|
N-yield goal (YG) :
|
NS
|
NS
|
NS
|
NS
|
NS
|
|
64 bu/ac
|
55
|
61
|
14.2
|
37
|
3
|
|
100 bu/ac
|
54
|
60
|
14.7
|
37
|
3
|
*Values followed by the same
letter in bold type do not differ significantly (.05 level).
Table
4b. Two-way effect means for year,
variety, seeding rate, and N-yield goal and
their effect on spring wheat
performance variables at Warner, SD.
|
Treatment Effects
|
Variety
performance variables
|
|
Height
inch
|
Lodging
%
|
Lodging
%
|
|
SR x Y:
|
2003
|
2004
|
2003
|
2004
|
|
|
1X (28) – 2003
|
35 a
|
40 a
|
2.3a*
|
2.9a
|
|
|
1.5X (42) – 2003
|
35 a
|
38 b
|
2.8b
|
2.9a
|
|
|
2X (56) – 2003
|
36 a
|
37 c
|
3.8c
|
3.3b
|
|
|
SR x V:
|
|
|
|
|
|
|
1X - Forge
|
|
|
|
|
2.2a
|
|
Oxen
|
|
|
|
|
2.5a
|
|
Walworth
|
|
|
|
|
3.2a
|
|
SD3623
|
|
|
|
|
2.7a
|
|
1.5X - Forge
|
|
|
|
|
2.5m
|
|
Oxen
|
|
|
|
|
2.5m
|
|
Walworth
|
|
|
|
|
3.4n
|
|
SD3623
|
|
|
|
|
3.1n
|
|
2X – Forge
|
|
|
|
|
3.3z
|
|
Oxen
|
|
|
|
|
3.3z
|
|
Walworth
|
|
|
|
|
3.7z
|
|
SD3623
|
|
|
|
|
3.8z
|
*Values followed by the same
letter in bold type do not differ significantly (.05 level).
At Warner (Table 3b), protein
and lodging were affected by SR, but not yield, test weight, or height. Protein values were highest for the 1X SR and
lowest for the 2X rate. Lodging was highest
at the 2X SR and lowest at the 1X rate.
Again, as with the variety
effect, the response of yield to the seeding rate effect differed between the
two locations. There was no effect of
seeding rate on yield at Warner where rainfall was plentiful and temperatures
were below average in late spring. This
lack of yield response to seeding rate is not surprising since plentiful
moisture likely cause seedling competition for moisture among the seeding rates
to be minimal. In contrast, the effect
of seeding rate on yield was significant at South Shore
where seasonal moisture was well below average.
In this case, where seedling competition for moisture was likely high,
the effect of seeding rate was more evident and significant.
N-yield goal (NYG) effect: At South
Shore (Table 3a), protein content was the only variety performance variable
affected by NYG. Increasing the yield
goal from 64 to 100 lb/ac increased the protein content of the grain. At Warner (Table 3b) however, NYG affected
both the protein content and the lodging percentage. Again, increasing NYG from 50 to 100 lb/ac
increased the grain protein content; but it also increased lodging.
Variety Performance Variables – Two-way effects:
Variety
x seeding rate (SR) effect: At South Shore (Table 3a), this interaction
affected
test weight. Both the 1X and 1.5X SR produced higher test
weight grain than the 2X rate for the varieties Forge, Oxen, and SD3623; but
not for the variety Walworth.
At Warner (Table 3b), the
variety x SR effect was only significant for lodging. Across all varieties the 1X SR exhibited the
least lodging and the 2X rate the most lodging.
Variety x N-yield goal
(NYG) effect: This effect was not evident at South Shore;
but did affect plant height at Warner (Table 3b). The effect was only significant for the variety
Forge, where the 100 bu/ac NYG resulted in taller
plants than did the 50 bu/ac NYG.
Yield Variables – Main effects:
At South Shore
(Table 4a), the impact of the main effects of variety and seeding rate (SR)
were only significant for the yield variables seeds/ft2, spikes/ft2,
seeds/spike, and spikes/seed kernel. The
variety Forge produced significantly fewer seeds/ft2 than the other
varieties. The varieties Oxen and Walworth
produced more spikes/ft2 and spikes/seed kernel than did Forge and
SD3623. The experimental line SD3623
produced significantly more seeds/spike than the other varieties.
The effect of SR on seeds/ft2
and spikes/ft2 tended to be inversely related. The 1X SR produced more seeds/ft2
than the 2X rate. In contrast, the 2X SR
produced more spikes/ft2 than the 1X rate. Seeds/spike and spikes/seed kernel responded
to SR similarly. In both variables, the
1X SR produced more seeds and spikes than did the 2X rate. In addition, neither the effect of variety or
SR affected seeds/lb or seed size. The
effect of N-yield goal (NYG) was not significant for any yield density variable.
At Warner (Table 4b) the effect
of variety was significant only for the yield variable seeds/spike. Seeds/spike was highest for Walworth and
lowest for Forge and SD3623. In
contrast, the effect of SR was significant for all of the yield variables
except seeds/ft2. The 1X SR produced
more seeds/ft2, more seeds/spike, and more spikes/seed kernel than
the 1.5X and 2X rates. In addition, the
1X and the 1.5X SR produced fewer seeds/lb (larger seed size) than the 2X rate. Again, at Warner, the effect of NYG on the
yield variables was not significant.
Variety effect: At South Shore,
all the yield variables, but seeds/lb (seed size), were significantly affected
by variety (Table 4a). Seeds/ft2 was
significantly higher for SD3623, Walworth, and Oxen than for Forge. Spikes/ft2 and spikes/seed kernel were
significantly higher for Walworth and Oxen than for SD3623 and Forge. In the case of spikes/seed kernel, it does
not indicate Walworth and Oxen produced more tillers/seed kernel; but it does
indicate they produced more spike bearing tillers/seed kernel. SD3623 produced significantly more
seeds/spike that the other varieties.
Walworth and Oxen produced significantly more spikes/seed kernel than SD3623
and Forge.
At Warner, seeds/spike was
the only yield density significantly affected by variety (Table 4b). Seeds/spike was highest for
Walworth and lowest for SD2623 and Forge.
Seeding rate effect: At South Shore,
all the yield density variables but seeds/lb (seed size) was significantly
affected by SR (Table 4a). Seeds/ft2
was significantly higher for both the 1X and 1.5X SR than for the 2X
rate. Spikes/ft2 was
significantly higher for the 2X SR and the lower for the 1X rate. The 1X SR produced the most and the 2X rate
the fewest seeds/spike. Likewise, the
1X SR produced the most and the 2X rate the fewest spikes/seed kernel.
Table
5a. Main effect means for variety,
seeding rate, and N-yield goal and their effect
on HR spring wheat yield
variables at South Shore, SD.
|
Treatment Effects
|
Yield
variables
|
|
|
Spikes/ft2
|
Seeds/spike
|
Spikes/seed kernel
|
Seeds/lb
|
|
Year (Y):
|
NS
|
|
NS
|
|
|
2003
|
57
|
17 b
|
1.46
|
20,425 a
|
|
2004
|
55
|
21 a
|
1.40
|
15,305 b
|
|
Variety (V):
|
|
|
|
NS
|
|
Forge
|
55 bc
|
20 b
|
1.39 b
|
18,680
|
|
Oxen
|
58 ab
|
18 c
|
1.48 a
|
17,523
|
|
Walworth
|
61 a
|
17 c
|
1.55 a
|
17,647
|
|
SD3623
|
52 c
|
22 a
|
1.30 c
|
17,610
|
|
Seeding rate (SR):
|
|
|
|
NS
|
|
1X (28) - recommended
|
52 b
|
21 a
|
1.87 a
|
17,058
|
|
1.5X (42) - intermediate
|
57 a
|
19 b
|
1.36 b
|
17,238
|
|
2X (56) - high
|
59 a
|
17 c
|
1.06 c
|
19,299
|
|
N-yield goal (YG) :
|
NS
|
NS
|
NS
|
NS
|
|
64 bu/ac
|
57
|
19
|
1.45
|
18,014
|
|
100 bu/ac
|
56
|
19
|
1.41
|
17,716
|
|
|
|
|
|
|
*Values followed by the same
letter in bold type do not differ significantly (.05 level).
Table
5b. Two-way effect means for year,
variety, seeding rate, and N-yield goal and
their effect on spring wheat
performance variables at South Shore,
SD.
|
Treatment Effects
|
Yield
variables
|
|
Seeds/spike
|
Seeds/spike
|
Spikes/seed kernel
|
|
|
V x Y:
|
2003
|
2004
|
|
|
|
Forge
|
16 b*
|
24 a
|
|
|
|
Oxen
|
17 b
|
18 b
|
|
|
|
Walworth
|
16 b
|
17 b
|
|
|
|
SD3623
|
20 a
|
24 a
|
|
|
|
SR x V:
|
|
|
|
|
|
1X - Forge
|
|
|
1.84 b
|
|
|
Oxen
|
|
|
1.94 ab
|
|
|
Walworth
|
|
|
2.04 a
|
|
|
SD3623
|
|
|
1.63 c
|
|
|
1.5X - Forge
|
|
|
1.27 n
|
|
|
Oxen
|
|
|
1.42 m
|
|
|
Walworth
|
|
|
1.49 m
|
|
|
SD3623
|
|
|
1.26 n
|
|
|
2X – Forge
|
|
|
1.04 z
|
|
|
Oxen
|
|
|
1.07 z
|
|
|
Walworth
|
|
|
1.12 z
|
|
|
SD3623
|
|
|
1.01 z
|
|
*Values followed by the same
letter in bold type do not differ significantly (.05 level).
Table
5b. Three-way effect means for year,
variety, seeding rate, and N-yield goal and
their effect on spring wheat
yield variables at South Shore,
SD.
|
Treatment Effects
|
Yield variables
|
|
Spikes/ft2
|
Seeds/spike
|
Spikes/seed kernel
|
|
SR x V x Y:
|
2003
|
2004
|
2003
|
2004
|
2003
|
2004
|
|
1X – Forge
|
51 bc
|
52 c
|
19 bc
|
25 ab
|
1.82
bc
|
1.87
a
|
|
Oxen
|
56 b
|
53 bc
|
20 b
|
21 de
|
1.99
b
|
1.89
a
|
|
Walworth
|
61 a
|
54 bc
|
18 bcd
|
19 ef
|
2.17
a
|
1.91
a
|
|
SD3623
|
48 c
|
43 d
|
23 a
|
27 a
|
1.72
c
|
1.54
b
|
|
1.5X – Forge
|
50 c
|
56 bc
|
16 def
|
24 bc
|
1.19
fg
|
1.34
c
|
|
Oxen
|
60 b
|
60 ab
|
17 cde
|
16 gh
|
1.42
e
|
1.42
bc
|
|
Walworth
|
69 a
|
57 bc
|
15 efg
|
16 gh
|
1.64d
|
1.34
c
|
|
SD3623
|
52 c
|
53 bc
|
20 b
|
23 bcd
|
1.24
f
|
1.27
c
|
|
2X – Forge
|
58 b
|
60 ab
|
14 fg
|
23 bcd
|
1.03
g
|
1.07
d
|
|
Oxen
|
65 a
|
55 bc
|
13 g
|
18 fg
|
1.16
f
|
0.98
d
|
|
Walworth
|
58 b
|
67a
|
16 def
|
15 h
|
1.04
g
|
1.19
c
|
|
SD3623
|
58 b
|
55 bc
|
18 bcd
|
22 cd
|
1.04
g
|
0.98
d
|
|
YG x V x Y:
|
|
|
|
|
|
|
|
50 bu./a – Forge
|
56 bc
|
53 cde
|
|
|
1.42 bcd
|
1.36 cd
|
|
Oxen
|
62 ab
|
57 abc
|
|
|
1.60 a
|
1.48 abc
|
|
Walworth
|
61 ab
|
62 a
|
|
|
1.56 ab
|
1.57 a
|
|
SD3623
|
52 c
|
51 de
|
|
|
1.30 def
|
1.29 d
|
|
100 bu./a– Forge
|
50 c
|
59 ab
|
|
|
1.27 f
|
1.49 ab
|
|
Oxen
|
58 b
|
54 cde
|
|
|
1.45 bc
|
1.38 bcd
|
|
Walworth
|
65 a
|
50 e
|
|
|
1.67 a
|
1.40 bcd
|
|
SD3623
|
54bc
|
56 bcd
|
|
|
1.38 def
|
1.24 d
|
*Values followed by the same
letter in bold type do not differ significantly (.05 level).
Table
5b. Three-way effect means at South Shore, SD
(continued).
|
Treatment Effects
|
Yield variables
|
|
Spikes/ft2
|
Spikes/seed kernel
|
Seeds/spike
|
|
2003
|
2004
|
2003
|
2004
|
50 bu/a
|
100 bu/a
|
|
Yield goal
|
Yield goal
|
|
YG x SR x Y:
|
|
|
|
|
|
|
|
50 bu./a – 1X
|
54 b*
|
54 b
|
1.92 a
|
1.92 a
|
|
|
|
1.5X
|
59 a
|
54 b
|
1.41 b
|
1.29 c
|
|
|
|
2X
|
61 a
|
60 a
|
1.09 c
|
1.07 d
|
|
|
|
100 bu./a– 1X
|
54 b
|
47 c
|
1.94 a
|
1.69 b
|
|
|
|
1.5X
|
56 b
|
59 a
|
1.34 b
|
1.40 c
|
|
|
|
2X
|
59 a
|
59 a
|
1.04 c
|
1.04 d
|
|
|
|
SR x VxYG:
|
|
|
|
|
|
|
|
1X - Forge
|
|
|
|
|
21 b
|
22 bc
|
|
Oxen
|
|
|
|
|
18 cde
|
23 ab
|
|
Walworth
|
|
|
|
|
19 bcd
|
17 def
|
|
SD3623
|
|
|
|
|
25 a
|
25 a
|
|
1.5X - Forge
|
|
|
|
|
21 b
|
19 d
|
|
Oxen
|
|
|
|
|
17 def
|
16 ef
|
|
Walworth
|
|
|
|
|
15 f
|
16 ef
|
|
SD3623
|
|
|
|
|
21 b
|
22 a
|
|
2X - Forge
|
|