Klamath Experiment Station
Effect of Seedpiece Size on Performance of Three Potato Varieties, 1997
K.A. Rykbost', K. Locket, and J. Maxwell'
A
bstract
Seedpiece size is an important factor
in the vigor and productivity of potato
crops. Varieties with limited numbers of eyes,
such as Shepody, require care in seed cutting
to avoid seedpieces with no eyes. Weak plants
or plants that are slow to emerge are often
associated with small seedpieces. A survey
was conducted of cut seed lots from commercial potato operations in the Klamath Basin.
Survey results showed poor uniformity in
seedpiece size and a trend for undersize
seedpieces in most seed lots examined.
Experiments were conducted in 1995,
1996, and 1997 to evaluate the effects of
seedpiece size on the performance of Russet
Burbank. Russet Norkotah, and Century Russet
varieties. Weighed seed tubers were four-cut to
obtain seedpiece sizes of 3/4,1-1/4,1-3/4,
2-1/4, and 2-3/4 oz. Small seedpieces resulted in
delayed emergence and reduced stem numbers in
all varieties. Effects of seedpiece size on yield and
tuber size distribution were greatest for Century
Russet and least for Russet Norkotah but were
different for all varieties over the three-year study.
Increasing seedpiece size increased yield of U.S.
No. I s and total yield but reduced tuber size. An
economic analysis. based on crop values for fresh
market use, found optimum seedpiece size of
2-1/4 oz for Russet Burbank and 1-3/4 oz for
Russet Norkotah and Century Russet. Manipulation of seedpiece size offers a means to
obtain tuber size distribution appropriate for
specific market requirements.
Introduction
Observations of cut seed from numerous
potato grower operations in several production
regions in the U.S. and Canada have consistently
shown poor uniformity of seedpiece size and a
trend for use of small seedpieces. With the
introduction of new varieties that typically have
fewer eyes than Russet Burbank, missing plants
because of seedpieces with no eyes has become
more common, particularly in the Shepody
variety. Examination of small and weak plants in
commercial fields frequently shows that weak
plants originate from a small seedpiece. This study
was initiated in 1994 to evaluate local seed cutting
practices and determine the response of crops to
a range of seedpiece sizes under local conditions.
The 1994 study was limited to the Russet
Burbank variety. A uniform experimental design
was established in 1995 to expand the study to
include Russet Norkotah and Century Russet.
This report summarizes the four-year project.
'/ Superintendent/Professor and Biological Sciences Research Technician III, respectively. Klamath
Experiment Station, Klamath Falls, OR.
2 / Klamath County Cooperative Extension Agent. Klamath Falls, OR.
Acknowledgments: Funding for this project from the Oregon Potato Commission, and cooperation from
several local potato growers is gratefully recognized.
42 Klamath Experiment Station 1997
Klamath Experiment Station
Effect of Seedpiece Size on Performance of Three Potato Varieties, 1997
Procedures
Commercial Seed Cutting
Samples of 40 to 50 lb of cut seed
were obtained from 18 commercial seed lots
in the Klamath Basin in 1994 and 1995. Each
lot was sorted to seedpiece sizes of <1.0 oz,
1.0 to 1.5 oz, 1.5 to 2.0 oz, 2.0 to 2.5 oz,
and > 2.5 oz. The weight and number of
seedpieces in each size fraction was recorded. Seed lots evaluated represented
nearly equal numbers of mechanical and hand
cutting operations and Russet Burbank and
Russet Norkotah varieties.
Potato Response to Seed Size
Seed tubers of Russet Burbank,
Russet Norkotah, and Century Russet varieties were obtained from local seed growers
each year. All seed lots were generation H or
generation III with very little virus content,
based on winter greenhouse tests. Tubers
were individually sized to 3, 5, 7, 9, and 11
oz, within a tolerance of one-quarter ounce,
to obtain appropriate size from four-cut
pieces to plant four replications of one-row
plots with 3/4, 1-1/4, 1-3/4, 2-1/4, and 2-3/4
oz seedpieces. Russet Burbank plots were 30
hills at 12-inch seed spacing in 32-inch rows.
Russet Norkotah and Century Russet plots
were 42 hills at 8.7-inch seed spacing. Eight
(Russet Burbank) or 11 (Russet Norkotah
and Century Russet) tubers were used for
each plot with two bud-end pieces discarded
in each case to ensure unifoi iii numbers of
bud-end and stem-end pieces for all plots.
Each year, cut seed was treated with Tops
2.5 fungicide immediately after cutting and
stored at approximately 55 °F and 95
percent relative humidity for about 10 days before
planting to allow suberization.
Plots were arranged in a split-plot design
with variety as the main plot and seedpiece size as
the split-plot. Potatoes were planted with a tworow, assisted-feed planter on June 13, 1995, May
24, 1996, and May 20, 1997. Standard cultural
practices included fertilizer rates of 1,000 lb/acre
of 15-15-15, banded at planting; weed control
with standard rates of Eptam and Matrix and
approximately 20 inches of irrigation water
applied with solid-set sprinklers. Crop protection
measures included fumigation with Telone II at 18
gpa, insect control with Di-syston, applied in the
seed furrow at planting and two applications of
Monitor, and fungal disease control with applications of Bravo, Ridomil-MZ, Mancozeb, and
Kocide at labelled rates. Vines were desiccated
with Diquat applied on September 26, 1995,
September 6, 1996 and September 2, 1997.
Potatoes were harvested with a one-row, diggerbagger on October 10, 1995, September 27, 1996,
and September 26, 1997. All tubers from each
plot were stored at about 55 °F until graded about
three weeks after harvest.
Emergence data were recorded at 22 days
after planting each year and at least once more when
all plants were emerged. Stem numbers were determined for 10 consecutive plants in each plot after vine
desiccation. Tubers were graded to USDA grade
standards. Specific gravity was determined by the
weight-in-air, weight-in-water method using 10 lb
samples of U.S. No. I s in the 8- to 12-oz size
fraction. Ten large tubers from each plot were cut
lengthwise to inspect for internal defects.
Economic interpretations were based on the
following assumptions:
1. Seed costs including cutting and treating
Klamath Experiment Station 1997 43
Klamath Experiment Station
Effect of Seedpiece Size on Performance of Three Potato Varieties, 1997
estimated to be $12/cwt.
2. Seed use based on 10-inch spacing (Russet
Burbank) or 8-inch spacing (Russet Norkotah
and Century Russet) in 36-inch rows with no
misses or multiple drops.
3. U.S. No. ls valued at $5.00/cwt for 4-8 oz;
$10.00/cwt for 8-12 oz; $8.00/cwt for > 12 oz.
4. U.S. No. 2s valued at $3.00/cwt.
5. Culls and Bs (< 4 oz) valued at $1.00/cwt.
All data were subjected to analysis of
variance using MSUSTAT software. Plant emergence data were analyzed using the arcsin transformation. Crop value data was calculated for
each plot and was included in the statistical
analysis. Analyses of data over years used a splitsplit-plot design with years as the main plot,
variety as the split-plot, and seedpiece size as the
split-split-plot.
Results and Discussion
Commercial Seed Cutting
Six cut seed lots from commercial potato
growers were examined in 1994, and 12 lots
were evaluated in 1995 (Table 1). Seedpiece size
distribution was highly variable within and between seed lots. One seed lot had an average
weight of only 1.14 oz/seedpiece and 75 percent
of seedpieces less than 1.5 oz on a number basis.
At the other extreme, one lot had an average
weight of 2.54 oz/seedpiece, less than 3 percent
under 1.5 oz, and 78 percent greater than 2.0 oz/
seedpiece. Russet Burbank seed lots were cut
slightly smaller than Russet Norkotah lots; however, this can be accounted for by the seed cutting
method. Clearly, seed lots that were hand cut had
fewer small seedpieces and more large pieces.
Uniformity of size was not much better in the hand
cut lots. Only three seed lots had 60 percent or
44 Klamath Experiment Station 1997
more pieces in the 1.5- to 2.5-oz size fractions. Three of the hand-cut seed lots had
excessive numbers of seedpieces over 2.5 oz,
while five machine-cut seed lots had over 50
percent of seedpieces less than 1.5 oz.
Potato Response to Seed Size
The response of Russet Burbank to
seedpiece size in the 1994 study was very similar
to results obtained in 1995-97, when three
varieties were evaluated. The 1994 findings have
been reported earlier and are not included in this
analysis and report.
Effects of seedpiece size on plant emergence were consistent between varieties and over
years (Table 2). Russet Burbank emerged slightly
earlier than the other varieties. In all varieties,
emergence was delayed by small seedpieces.
Final stands were over 95 percent in all cases
except the 3/4 oz seed size for Century Russet in
1995 (90 percent) and 1997 (88 percent).
Differences in canopy vigor were visually evident
in all varieties through the first one-half of the
vegetative growth phase. Plants from large
seedpieces achieved row closure 10 days to 2
weeks earlier than plants from the smallest
seedpieces. Stem numbers accounted for much
of the differences in plant size. Stem numbers
were slightly higher in Century Russet than other
varieties and were higher for large seedpieces in
each year (Table 2).
Favorable weather throughout the 1997
growing season resulted in very high yields.
Average total No. I yields of 453. 480, and 604
cwt/acre for Russet Burbank, Russet Norkotah,
and Century Russet, respectively, were 42, 70
and 28 percent greater than means for the
previous two years. The response to seedpiece
Klamath Experiment Station
Effect of Seedpiece Size on Performance of Three Potato Varieties, 1997
size was similar for all varieties. The interaction between variety and seedpiece size was
not significant for any yield parameters in
1997. As in previous years, Century Russet
experienced the largest yield response and
Russet Norkotah was least responsive to seed
size (Table 3). Total No. 1 yields were at least
80 cwt/acre higher for 1-3/4 oz than for 3/4 oz
seedpieces in all varieties. Century Russet
achieved maximum yield of No. ls at 1-3/4 oz
seed size. Russet Burbank and Russet Norkotah produced maximum No. 1 yields at 2-3/4
oz. Seedpiece size greatly influenced tuber
size distribution in all varieties. As seed size
increased, yields of small No. is and Bs
increased rapidly, while yield of No. ls > 12 oz
declined.
Effects of variety and seedpiece size on
yields over three years are summarized in Table 4.
The statistical significance of experimental variables and interactions are shown in Table 5. Yield
differences between years were significant for all
parameters except culls. Significance was found
for all parameters between varieties. Russet
Burbank produced similar yields of No. 1s, but
higher yields of No. 2s and culls than Russet
Norkotah. Century Russet achieved higher No. 1
yields in all size fractions. The variety-by-year
interaction was also significant for all parameters.
This waslargely due to a much greater difference
in yields for Russet Norkotah than the other
varieties over years. Russet Norkotah experienced very low yields and little response to
seedpiece size in 1995. Earlier-than-normal vine
death suggested some form of the early dying
complex affected Russet Norkotah in 1995. In
1996 and 1997, the response of Russet
Norkotah to seedpiece size was similar to the
responses observed for Russet Burbank and
Century Russet.
Effects of seedpiece size on yields
were significant for all parameters except
yields of No. 2s and culls over years. Total No.
1 yields increased by 38 and 44 cwt/acre as
seed size increased from 3/4 oz to 1-1/4 and 13/4 oz. Further increases in seedpiece size
resulted in little yield increase but reduced
tuber size. Differences in response to seedpiece size between varieties were not significant except for yield of 4- to 8-oz No. ls and
total yield.
Seedpiece size did not affect specific
gravity or internal defects in any variety or year.
Specific gravity was always measured in tubers
within 8 to 12 oz. As seedpiece size altered tuber
size distribution, there may have been minor
affects on specific gravity because of changes in
tuber size distribution. Large tubers were inspected for internal defects. Hollow heart and
brown center were observed in less than 10
percent of tubers examined each year. Seedpiece
size did not affect the incidence of defects in
tubers examined.
Evaluation of effects of seedpiece size on
economics of potato production requires an
assessment of increased seed costs for use of
larger seedpieces. Based on the assumptions
previously stated, seed costs are shown in Table
6. Seed costs are less for Russet Burbank
because of lower plant populations used for this
variety. The values assigned for yield components
are the approximate values for fresh-market
russets in the Klamath Basin in the late fall of
1997. Typical Klamath Basin Russet Norkotah
crops were returning about $4.00/cwt to growers
at these prices.
-
Klamath Experiment Station 1997 45
Klamath Experiment Station
Effect of Seedpiece Size on Performance of Three Potato Varieties, 1997
Averaged over three years, the incremental increase in gross crop value for Russet
Burbank was about $200/acre for seed size
increases up to 2-1/4 oz (Table 6). Gross value
declined by $200/acre for the last size increase.
Russet Norkotah experienced increases of $150
and $70/acre for the first incremental increases in
seedpiece size and little change among the three
largest sizes. Century Russet had incremental
increases in gross value of about $500, $300, and
S 100/acre to the 2-1/4 oz size and no change for
the final incremental increase in seed size.
When crop values are adjusted for the
change in seed costs associated with variable
seedpiece size, the varieties responded differently.
Russet Burbank achieved economically optimum
production at 2-1/4 oz seed size. The increase in
value from 3/4 to 2-1/4 oz was $480/acre.
Russet Norkotah was not economically responsive. The largest seed size produced the lowest
returns. Century Russet reached maximum returns
at 1-3/4 oz seed size. The increase in value from
3/4 to 1-3/4 oz was $620/acre for Century
Russet.
Conclusions
This study has confirmed the need for
better quality control in seed-cutting operations.
Significant economic benefits have been demonstrated for use of seedpieces in the range of
1-3/4 to 2-1/4 oz. Findings also show tuber size
to meet specific market requirements can be
manipulated by using smaller seedpieces when
large tubers are desirable, and larger seedpieces
when small tubers are at a premium. An example
would be use of large seedpieces to produce
higher yields of creamer size tubers for redskinned or specialty varieties.
46 Klamath Experiment Station 1997
Klamath Experiment Station
Table 1. Seedpiece size distribution in 18 commercial cut seed lots evaluated at 'Klamath Falls, OR, in
1994 and 1995.
Variety
Cutting
method
Average
weight
< 1.0 oz
1.0-1.5 oz
Seedpiece size
1.5-2.0 oz
2.0-2.5 oz
> 2.5 oz
% (number basis)
OZ
R. Burbank
R. Burbank
R. Burbank
R. Burbank
R. Burbank
R. Burbank
R. Burbank
R. Burbank
Machine
Machine
Machine
Machine
Machine
Machine
Hand
Hand
1.50
1.14
1.53
2.05
1.56
1.64
2.32
1.65
16.5
46.0
19.9
3.9
13.2
24.7
0.0
8.7
29.7
28.8
30.2
17.3
34.4
24.3
5.1
30.4
26.1
17.2
33.0
29.0
35.9
23.3
24.0
40.9
19.5
7.0
14.8
29.8
13.9
13.8
39.8
16.6
8.2
1.0
2.1
20.0
2.6
14.4
31.1
3.4
R. Norkotah
R. Norkotah
R. Norkotah
R. Norkotah
R. Norkotah
R. Norkotah
R. Norkotah
R. Norkotah
R. Norkotah
R. Norkotah
Machine
Machine
Machine
Machine
Hand
Hand
Hand
Hand
Hand
Hand
1.49
1.42
1.47
1.56
2.54
1.82
1.65
2.30
1.77
1.58
29.5
30.9
21.9
19.7
0.0
4.5
4.5
1.9
5.9
13.8
20.5
24.2
30.2
29.2
2.6
25.0
34.3
6.9
14.1
24.0
20.2
23.3
32.3
29.5
19.5
35.9
38.6
15.9
47.8
37.6
15.9
14.0
12.3
15.0
32.2
24.4
18.3
33.7
20.5
18.5
13.9
7.6
3.3
6.6
45.7
10.2
4.3
41.6
11.7
6.1
R. Burbank
R. Norkotah
Mean
Mean
1.67
1.76
16.5
13.3
25.0
21.1
28.7
30.0
19.4
20.5
10.4
15.1
Mean
Mean
Machine
Hand
1.54
1.95
22.6
4.9
26.8
17.8
27.0
32.5
15.6
25.5
8.0
19.3
Klamath Experiment Station 1997 47
Klamath Experiment Station
Table 2. Effect of seedpiece size on percent emergence 22 days after planting and number of stems per
plant for Russet Burbank, Russet Norkotah, and Century Russet potatoes grown at Klamath Falls, OR,
1995-97.
Variety
Seed size (oz)
1995
Emergence (%) 1996
1997 mean
1995
Stems/plant
mean
1996
1997
Russet Burbank
3/4
1-1/4
1-3/4
2-1/4
2-3/4
82
97
96
96
100
91
94
100
98
99
44
52
59
60
61
72
81
85
85
87
1.90
2.45
2.65
- 3.05
3.23
2.05
2.45
2.55
3.20
3.45
1.58
1.85
2.18
2.58
2.58
1.84
2.25
2.46
2.94
3.09
Russet Norkotah
3/4
1-1/4
1-3/4
2-1/4
2-3/4
46
62
70
79
74
50
67
67
64
77
25
38
51
53
67
40
56
63
65
73
2.08
2.63
3.00
3.28
3.40
2.28
2.40
2.63
3.30
3.38
1.28
1.93
2.18
2.48
2.53
1.88
2.32
2.60
3.02
3.10
Century Russet
3/4
1-1/4
1-3/4
2-1/4
2-3/4
38
54
76
79
79
64
65
81
77
78
14
20
21
30
38
39
46
59
62
65
2.15
2.73
3.48
3.65
3.73
2.10
2.83
2.95
3.78
3.53
1.70
2.30
2.98
3.10
3.43
1.98
2.62
3.14
3.51
3.60
Variety main effect:
Russet Burbank
Russet Norkotah
Century Russet
94
66
65
96
65
73
55
47
25
82
59
54
2.66
2.88
3.15
2.74
2.80
3.04
2.15
2.08
2.70
2.52
2.59
2.96
CV (%)
LSD (P 0.05)
21
10
12
6
24
NS
18
10
18
0.42
20
0.40
26
0.46
13
0.13
55
71
81
85
84
68
75
83
80
85
28
37
44
48
55
50
61
69
71
75
2.04
2.60
3.04
3.33
3.45
2.14
2.56
2.71
3.43
3.45
1.52
2.03
2.45
2.72
2.85
1.90
2.40
2.73
3.16
3.25
10
6
8
5
19
7
18
7
11
0.27
12
0.30
12
0.22
13
0.17
Seed size effect:
3/4
1-1/4
1-3/4
2-1/4
2-3/4
CV (c7c)
LSD (P = 0.05)
48 Klamath Experiment Station 1997
Klamath Experiment Station
Table 3. Effect of seedpiece size on yield, grade, and tuber size distribution of Russet Burbank, Russet
Norkotah, and Century Russet potatoes grown at Klamath Falls, OR, 1997.
Variety
Seed
size
4 - 8 oz
Yield U.S. No. is
8-12 oz
> 12 oz
total
Bs
Yield
No. 2s culls
total
$/A
cwt/A
OZ
Gross
value
R. Burbank
3/4
1-1/4
1-3/4
2-1/4
2-3/4
94
91
174
200
197
131
136
173
181
204
178
135
139
113
118
404
363
485
495
519
25
30
42
-57
62
76
59
81
63
65
42
42
60
37
39
547
494
668
651
686
3510
3150
4050
4000
4270
R. Norkotah
3/4
1-1/4
1-3/4
2-1/4
2-3/4
95
149
165
180
229
115
168
194
211
191
211
138
148
115
92
420
455
506
506
512
13
31
37
56
65
16
15
13
11
8
4
8
3
6
4
453
508
559
578
588
3370
3610
4020
4020
3880
Century R.
3/4
1-1/4
1-3/4
2-1/4
2-3/4
136
201
220
233
236
158
208
254
213
252
246
182
192
168
124
540
591
666
614
611
31
46
39
54
66
27
19
11
7
20
8
5
4
9
6
605
660
720
684
703
4340
4640
5250
4720
4820
151
164
205
165
176
217
137
141
182
453
480
604
43
40
47
69
13
17
44
5
7
609
537
674
3800
3780
4750
23
30
26
37
42
NS
20
81
37
NS
55
14
173
25
17
79
690
108
147
186
205
221
135
171
207
202
216
212
152
159
132
111
454
469
552
538
547
23
35
39
55
64
40
31
35
27
31
18
19
22
17
16
535
554
649
637
659
3740
3800
4440
4250
4320
17
25
18
27
26
33
11
46
27
10
34
10
82
NS
10
50
12
Variety main effect:
R. Burbank
R. Norkotah
Century R.
CV (%)
LSD (P = 0.05)
22
Seed size effect s
3/4
1-1/4
1-3/4
2-1/4
2-3/4
CV (9-)
LSD (P = 0.05)
390
Klamath Experiment Station 1997 49
Klamath Experiment Station
Table 4. Mean effect of seedpiece size on yield, grade, and tuber size distribution over three years for
Russet Burbank. Russet Norkotah, and Century Russet potatoes grown at Klamath Falls, OR, l 995-97.
Variety
Seed
size
4-8 oz
Yield U.S. No. ls
8-12 oz
> 12 oz
oz
total
Bs
Yield
No. 2s
culls
total
cwt/A
R. Burbank
3/4
1-1/4
1-3/4
2-1/4
2-3/4
93
129
162
185
178
112
126
144
145
146
93
81
79
82
56
298
336
385
412
380
30
37
. 48
62
70
42
34
38
38
36
32
23
25
20
36
401
431
495
533
522
R. Norkotah
3/4
1-1/4
1-3/4
2-1/4
2-3/4
100
133
148
156
172
110
130
135
141
139
112
82
82
67
64
321
345
363
363
376
20
38
45
52
60
10
11
10
10
8
10
11
7
10
3
361
403
426
435
448
Century R.
3/4
1-1/4
1-3/4
2-1/4
2-3/4
131
177
214
223
266
138
189
209
209
203
154
126
118
126
97
423
491
540
557
566
28
49
51
57
79
15
10
7
8
12
11
8
10
9
9
476
558
608
631
665
149
142
202
135
131
189
78
81
124
362
354
515
49
43
52
38
10
10
27
8
10
476
415
588
16
10
20
11
40
14
13
20
32
6
51
4
97
5
11
20
108
139
175
188
205
120
143
163
165
163
120
103
93
92
72
347
385
429
444
441
26
40
48
57
70
22
19
18
19
18
18
14
14
13
16
413
458
510
533
545
16
12
20
14
40
18
13
25
32
7
51
NS
97
NS
11
25
Variety main effect:
R. Burbank
R. Norkotah
Century R.
CV (%)
LSD (P = 0 05)
Seed size effect:
3/4
1-1/4
1-3/4
2-1/4
2-3/4
CV (%)
LSD (P= 0.05)
50 Klamath Experiment Station 1997
Klamath Experiment Station
Table 5. Statistical summary of effects of seedpiece size, three varieties, and year on yield components
and gross crop value of potatoes grown at Klamath Falls, OR, 1995-97.
Yield U.S. No. Is
8-12 oz > 12 oz
Factor
4-8 oz
Year
**
**
Variety
**
**
Year x Variety
**
Size
**
Year x Size
total
Gross
value
NS
**
**
**
**
**
**
**
**
**
**
**
NS
NS
**
**
**
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
Yield
No. 2s
culls
total
Bs
**
**
•*
**
**
**
**
**
**
**
**
**
NS
**
**
Variety x Size
**
NS
NS
Year x Variety x Size
**
NS
NS
NS
NS: not significant.
* Significant at P= 0.05.
** Significant at P= 0.01.
Klamath Experiment Station 1997 51
Klamath Experiment Station
Table 6. Effect of seedpiece size on gross crop value, seed costs, and gross value less seed costs for
Russet Burbank. Russet Norkotah, and Century Russet potatoes grown at Klamath Falls, OR, 1995-97.
Variety
Seed
size
Gross crop value
1995 1996 1997 mean
Seed
cost
Gross value less seed cost
1995 1996 1997 mean
$/A
OZ
Russet Burbank
3/4
1-1/4
1-3/4
2-1/4
2-3/4
1910
2240
2590
3070
2390
2080
2770
2530
2570
2370
3510
3150
4050
4000
4270
2500
2720
3060
3210
3010
120
200
280
350
430
1790
2040
2310
2720
1960
1960
2570
2250
2220
1940
3390
2950
3770
3650
3840
2380
2520
2780
2860
2580
Russet Norkotah
3/4
1-1/4
1-3/4
2-1/4
2-3/4
1770
1760
1610
1960
1880
2510
2730
2820
2450
2810
3370
3610
4020
4020
3880
2550
2700
2820
2810
2860
150
250
340
440
540
1 620
1510
1270
1520
1340
2360
2480
2480
2010
2270
3220
3360
3680
3580
3340
2400
2450
2480
2370
2320
Century Russet
3/4
1-1/4
1-3/4
2-1/4
2-3/4
2940
3990
4050
4900
4650
2760
2960
3160
3210
3300
4340
4640
5250
4720
4820
3350
3860
4180
4280
4260
150
250
340
440
540
2790
3740
3710
4460
4110
2610
2710
2820
2770
2760
4190
4390
4910
4280
4280
3200
3610
3840
3840
3720
Mean
3/4
1-1/4
1-3/4
2-1/4
2-3/4
2210
2660
2780
3310
2970
2450
2820
2840
2740
2830
3740
3800
4440
4250
4320
2800
3090
3350
3430
3370
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
340
310
390
210
NC
NC
NC
NC
NC
LSD (P = 0.05)
NC: Not calculated.
52 Klamath Experiment Station 1997