HORTSCIENCE 35(6):1141–1150. 2000.
Screening the Cucumber Germplasm
Collection for Combining Ability for
Yield
Todd C. Wehner1,2 and Nischit V. Shetty2
Department of Horticultural Science, North Carolina State University,
Raleigh, NC 27695-7609
Raymond L. Clark3
U.S. Department of Agriculture Regional Plant Introduction Station, Ames,
IA 50011
Additional index words. Cucumis sativus, fruiting, germplasm evaluation, vegetable
breeding, fruit number
Abstract. Cucumber (Cucumis sativus L.) plant introduction (PI) accessions from the
regional PI station at Ames, Iowa were evaluated in open-field production for singleharvest yield at Clinton, N.C. and Ames, Iowa. Check cultivars and experimental
inbreds were also tested for comparison with the PI accessions (the three groups
hereafter collectively referred to as cultigens). In order to make the evaluation more
uniform for all cultigens regardless of sex expression and fruit size, all were crossed with
Gy 14, a gynoecious pickling cucumber inbred used commonly in the production of
commercial hybrids. The resulting 761 gynoecious hybrids were tested for early, total,
and marketable yield using recommended cultural practices. Results were obtained for
725 cultigens at both locations. Significant differences were observed among cultigens
for all traits evaluated. Differences between the two locations were also significant for
total yield, corrected total yield, and percentage of early fruit. The interaction of cultigen
and location was significant for standardized total yield and standardized corrected
total yield. The highest yielding hybrids at both locations were produced using the
following cultigens as male (paternal) parents: PI 422185, PI 390253, PI 175120, PI
173889, PI 267087, PI 175686, PI 178888, PI 385967, PI 458851, and PI 171601. The
highest and lowest yielding paternal parents from the germplasm screening study were
retested, along with check cultigens in a multiple-harvest trial at Clinton, N.C. Cultigens
were evaluated directly, rather than as hybrids with Gy 14, and fruit number, fruit
weight, and sex expression were recorded. Most cultigens performed as expected for the
yield traits in the retest study. The exceptions were ‘Wautoma’ and PI 339250, which
were among the low and high yielders in the first test, but were ranked as medium and
low, respectively, in the retest study.
Cucumber is thought to have originated in
India (Harlan, 1975), with domestication
occurring later throughout Europe. Breeding
for yield has been one of the important
objectives of many cucumber breeding
programs since the 1900s (Wehner, 1989).
Yield of pickling cucumber has been improved
by incorporating disease resistance into cultiReceived for publication 7 Sept. 1999. Accepted for
publication 14 Feb. 2000. The use of trade names in
this publication does not imply endorsement by the
North Carolina Agricultural Research Service
(NCARS) of the products named, nor criticism of
similar ones not mentioned. Research funded in part
by a grant from the North Carolina Pickle Producers
Association. We gratefully acknowledge the technical assistance of R.R. Horton, Jr. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this
paper therefore must be hereby marked advertisement solely to indicate this fact.
1
To whom requests for reprints should be addressed.
E-mail address: todd_wehner@ncsu.edu
2
Professor and Graduate Research Assistant, respectively.
3
Research Leader (retired).
HORTSCIENCE, VOL. 35(6), OCTOBER 2000
vars (Peterson, 1975) and using improved
cultural practices (Cargill et al., 1975). Increased yield has also resulted from improvement of qualitative traits such as gynoecious
sex expression and uniform green fruit color
(improved percentage of marketable fruit)
(Wehner, 1989).
However, improvement in yield in recent
years has been limited. Additional yield improvement might be achieved by identifying
new sources of germplasm for high yield. The
cucumber germplasm collection is a good place
to find new sources of high yielding cultigens
because no previous work has been done on
screening the collection for yield. However,
measurement of yield in a diverse array of
cucumber cultigens can be difficult. Yield is
usually measured as fruit number, weight, or
value per unit area or per plant. Fruit number
was more stable than fruit weight or fruit value
for yield measurement in a once-over harvest
trial of cucumber (Ells and McSay, 1981) and
had a higher heritability (0.17) than fruit weight
(0.02) (Smith and Lower, 1978).
Large-plot, multiple-harvest trials in
multiple years, locations, seasons, and repli-
cations would be ideal for yield measurement.
However, it would be nearly impossible to
include >700 cultigens in such trials. Single
harvest trials are efficient for yield measurement, but introduce the problem of the optimum time to harvest each plot for maximum
yield. Miller and Hughes (1969) reported that
harvesting when 14% to 31% of the fruits in a
plot were oversized (>51 mm diameter for
pickling cucumber and >60 mm diameter for
fresh market cucumber) was optimum for
maximum value in once-over harvest for
‘Piccadilly’ and ‘Southern Cross’ gynoecious
hybrids in North Carolina. Chen et al. (1975),
using a computer simulation, reported that
plots harvested at 10% oversized fruit stage
gave an optimum yield for ‘Piccadilly’ hybrid
under North Carolina conditions. Colwell and
O’Sullivan (1981) reported that the optimum
harvest stage to maximize yield for ‘Femcap’
and ‘Greenstar’ gynoecious hybrids occurred
when 5% to 15% of the fruit in a plot were
oversized.
Small-plot trials are efficient, but plots
should not be too small. Yield of cultivars in
single-plant hills was poorly correlated with
large, replicated plots harvested several times
(Wehner, 1986; Wehner and Miller, 1984). In
addition, greenhouse evaluation of yield, based
on fruit number of single plants, was not
correlated (r = 0.09–0.15) with yield in field
trials (Nerson et al., 1987). Once-over harvest
trials with three replications are optimum for
determining which cucumber cultigens should
be tested further in multiple-harvest trials
(Wehner, 1986; Wehner and Miller, 1984). A
plot size of 1.2 m × 1.5 m was found to be
optimum for yield evaluation of pickling
cucumber when paraquat (1,1´-dimethyl-4,4´bipyridinium ion) was used to simulate onceover harvest (Swallow and Wehner, 1986). In
cucumber, small-plot, single-harvest trials were
more efficient than large-plot, multiple-harvest
trials (Wehner, 1986 , 1989; Wehner and Miller,
1987).
Swallow and Wehner (1989) suggested
that maximum information (1/variance) was
obtained by allocating test plots of cucumber
cultigens over different seasons and years rather
than different locations and replications. However, use of locations and replications was less
expensive than use of seasons and years. Field
evaluation at the Clinton location was more
efficient than at three other locations tested in
North Carolina (Wehner, 1987a).
The >700 cultigens in the U.S. Dept. of
Agriculture (USDA) cucumber germplasm collection range from androecious to monoecious
to gynoecious. Thus, measuring yield of a
diverse set of cultigens in a single-harvest trial
is difficult, even though that method is the
most efficient. Some of the cultigens are highly
staminate in flowering habit, so will not produce much fruit. Even so, androecious cultigens might have useful genes for yield. For
that reason, we crossed each cultigen with Gy
14 to make gynoecious hybrids. In that way,
yield of all cultigens from the germplasm
collection could be expressed in a gynoecious
background with the potential to set fruit at
many nodes. By measuring the combining
1141
BREEDING, CULTIVARS, ROOTSTOCKS, & GERMPLASM RESOURCES
Table 1. Fruit yield traits (yield in 1000 fruit/ha)z for the cucumber germplasm collection tested at two locations for combining ability with Gy 14 (cultigens
ranked by standardized corrected total fruit number over both locations).
Cultigen
Total
Both locations
Std. Corr. Std. corr. Early
total Total total
(%)
PI 422185
PI 390253
PI 175120
PI 173889
PI 267087
PI 175686
PI 178888
PI 385967
PI 458851
PI 171601
Polaris
PI 427090
PI 226461
PI 169397
PI 171610
PI 370019
PI 169380
PI 391568
PI 370022
PI 179678
91
104
87
88
81
86
96
27
55
110
51
109
82
92
74
20
88
41
37
49
97
119
145
153
151
149
128
111
117
123
107
110
138
148
117
82
140
113
155
120
171
147
114
104
86
104
115
38
92
130
63
153
101
94
83
37
91
51
37
57
167
166
160
157
157
156
152
150
150
149
149
147
146
145
145
145
145
144
143
141
0
39
55
65
75
68
58
100
52
44
67
7
58
68
59
100
68
70
100
50
78
72
77
76
76
71
58
62
53
47
36
32
46
13
16
135
101
124
122
109
108
91
103
89
87
79
70
48
24
34
78
79
77
76
76
71
62
62
53
48
40
33
46
16
16
126
122
115
113
103
101
100
96
84
84
79
72
47
36
33
55
59
54
51
41
46
65
62
50
52
50
49
40
41
42
25
21
36
22
32
22
11
12
28
25
22
12
18
14
6
12
61
21
30
119
6
45
58
49
35
54
43
36
44
44
36
37
38
28
23
14
18
100
29
26
141
5
28
21
42
30
32
31
14
12
28
31
26
12
18
15
9
13
65
24
31
164
7
54
54
53
52
51
50
45
44
42
42
39
38
28
25
25
23
100
31
28
144
5
45
50
52
50
0
0
67
50
40
40
56
100
50
35
50
40
58
5
17
100
20
Regal
Gy 4
Calypso
Dasher II
Sprint 440
M 21
Gy 5
Gy 2
SMR 58
Sumter
Addis
Wautoma
M 27
WI 2757
Marketmore
PI 357856
PI 183127
PI 458855
PI 370450
Magnolia
PI 379283
PI 370447
PI 183056
PI 379284
PI 379282
PI 432874
Stono
Cubit
PI 368554
PI 357853
PI 368559
Mean
LSD
(5%)
Range
Range/LSD
CV
Std.
Total total
--22
36
41
44
38
24
27
37
19
25
--34
35
27
20
32
32
37
43
High yielding male parents
------79
39
139
151
36
138
171
41
156
183
54
202
165
38
149
103
34
137
111
38
150
155
43
159
69
39
137
98
44
162
------143
34
132
146
38
148
114
45
175
82
37
145
134
39
152
130
47
177
155
37
143
186
59
228
Check/Cultivars
35
148
35
135
24
96
42
157
32
133
32
122
28
119
28
109
27
109
27
102
25
102
25
94
20
85
28
108
25
107
25
98
23
96
23
89
25
105
26
100
28
116
28
108
22
92
25
97
6
13
6
17
8
39
15
67
12
50
12
49
Low yielding male parents
16
70
23
94
23
100
23
92
14
48
14
46
14
48
23
80
----------------12
38
16
53
26
108
26
104
16
58
16
55
13
43
13
42
16
53
16
49
12
38
12
38
15
48
15
45
6
30
7
36
8
24
15
56
11
38
15
57
24
100
26
100
9
27
11
26
24
17
27
16
38
172
52
211
4
6
5
8
F ratios
4**
8**
3**
8**
Cultigen
3.8** 4.9**
3.2**
4.0**
6.1**
Location
42.0** 2.0NS 38.9**
2.2NS 210.0**
Cult. × loc.
2.6** 1.8**
2.3**
1.8**
1.7**
z
Data are means of three replications per location.
NS, *, **
Nonsignificant or significant at P ≤ 0.05 or 0.01 level, respectively.
1142
Iowa
Corr. Std. corr. Early
Total
total
(%)
North Carolina
Corr. Std. corr. Early
Total
total
(%)
Total
Std.
total
--100
100
100
100
100
100
100
100
100
100
--100
100
100
100
100
100
100
100
91
131
138
135
118
133
143
--73
140
102
109
131
149
120
--143
59
--56
97
132
139
136
119
134
145
--78
141
125
110
132
150
121
--145
81
--55
171
183
192
168
118
170
169
--141
160
102
153
169
149
120
--143
59
--56
167
175
182
159
112
162
162
--141
153
121
147
161
143
116
--138
78
--54
0
19
11
30
50
35
29
--4
26
0
7
16
37
19
--36
9
--0
98
91
93
95
99
95
99
--100
96
89
77
99
96
97
--95
91
--100
100
100
100
100
100
74
100
100
100
100
100
90
100
81
70
122
104
115
124
105
117
97
99
82
69
43
43
72
16
20
123
104
115
125
108
115
97
99
82
69
42
44
71
14
18
122
104
115
124
105
117
97
99
82
70
52
43
72
16
20
117
99
110
118
103
108
92
94
80
67
50
42
68
14
18
10
32
15
1
5
17
30
24
0
3
0
0
0
0
0
99
97
97
87
95
97
96
91
96
96
87
100
96
100
100
100
100
100
100
----100
100
100
100
100
100
100
88
100
100
100
9
6
30
3
30
18
50
27
32
22
11
4
36
32
24
--22
20
5
13
100
41
26
166
4
29
16
49
26
54
43
32
2
35
31
29
--9
18
9
11
100
47
30
170
4
30
18
60
35
32
31
11
4
36
44
31
--22
20
5
13
105
46
27
192
4
28
17
57
33
51
50
30
3
34
42
34
--11
18
9
12
100
47
29
183
4
9
0
3
0
0
0
0
0
0
0
33
--0
0
0
10
15
20
84
63
3
100
100
89
79
67
100
100
100
100
95
83
--100
87
100
100
93
11
8
80
7
4**
3**
2**
3**
2**
3**
Marketable
(%)
3**
HORTSCIENCE, VOL. 35(6), OCTOBER 2000
ability of yield, we would be able to identify
cultigens that contributed useful, dominant
genes for yield to their hybrid.
A disadvantage of measuring yield of the
germplasm collection as combining ability
with a gynoecious tester is that cultigens with
recessive genes for yield would not perform as
well. Therefore, cultigens that rank high in this
evaluation of combining ability for yield would
be excellent choices for use in a breeding
program for yield, but cultigens that do not
rank high might also be excellent choices.
Therefore, low performers should be retested
for yield using methods other than combining
ability.
In the breeding program at North Carolina
State Univ., we intend to measure yield of the
cucumber germplasm collection using a threestage process. First, testing of all available
cultigens using combining ability with a
gynoecious tester in small-plot, single-harvest
trials. Second, testing of all available cultigens
for yield per se in small-plot, single-harvest
trials after treating the plants with ethrel
(2-chloroethylphosphonic acid) to increase
gynoecious sex expression. Third, evaluation
of the high-yielding cultigens from the previous two stages using large-plot, multiple-harvest trials in multiple seasons and years. This
study deals with the first stage of that process.
The objective of this study was to evaluate
all available cucumber cultigens for combining ability for yield at two locations using a
gynoecious tester. Identification of the highest
yielders was followed by a retest of performance per se to verify performance for use in
yield improvement in breeding programs for
commercial cultivars.
Materials and Methods
All experiments were conducted at the
Horticultural Crops Research Station, Clinton,
N.C., and the Regional Plant Introduction
Station, Ames, Iowa. The experiments were
Table 2. Correlations among fruit yield traits for the cucumber germplasm collection tested at two locations.
Cultigen
Std.
total
Total
0.81
Standardized total
--Corrected total
Standardized corrected total
Early yield (%)
Both locations
Corr. Std. Corr. Early
total
total
(%)
Iowa
Std. Corr. Std. Corr. Early
Total total total
total
(%)
0.92
0.69
---
0.44
0.76
0.40
0.67
0.17
0.73
0.86
0.79
---
Total
Standardized total
Corrected total
Standardized corrected total
Early yield (%)
–0.14
0.26
–0.27
0.15
---
---
Both locations
0.43 0.30
0.31
0.77 0.54
0.56
0.39 0.39
0.39
0.66 0.72
0.74
0.19 0.05
0.08
Iowa
0.99 0.76
0.76
--0.73
0.75
--0.99
---
Std.
Total total
North Carolina
Corr. Std. Corr. Early Marketable
total
total
(%)
(%)
0.13
0.16
0.14
0.17
0.10
0.92
0.85
0.77
0.73
0.26
0.91
0.86
0.77
0.75
0.26
0.87
0.78
0.89
0.81
0.16
0.86
0.78
0.89
0.83
0.15
0.44
0.47
0.37
0.37
0.63
0.04
0.12
0.00
0.06
0.15
0.17
0.16
0.16
0.15
---
0.33
0.34
0.18
0.19
0.10
0.33
0.34
0.19
0.21
0.10
0.32
0.32
0.21
0.21
0.12
0.32
0.32
0.22
0.23
0.12
0.25
0.26
0.14
0.16
0.08
0.14
0.15
0.08
0.10
0.04
---
0.99
---
0.91
0.90
---
0.90
0.91
0.42
---
0.51
0.49
0.02
0.16
---
0.05
0.05
0.02
0.16
0.16
North Carolina
Total
Standardized total
Corrected total
Standardized corrected total
Early yield (%)
Table 3. Mean sandardized corrected yield (1000 fruit/ha) for 761 cucumber cultigens tested at two locations (cultigens ranked by average yield
at both locations.
Cultigen name
PI 422185
PI 390253
PI 175120
PI 173889
PI 267087
PI 175686
PI 178888
PI 385967
PI 458851
PI 171601
Polaris
PI 427090
PI 226461
PI 169397
PI 171610
PI 370019
PI 169380
PI 391568
PI 370022
PI 179678
PI 401732
PI 344445
PI 169391
PI 174172
PI 342950
PI 280096
Seed sourcez
Czechoslovakia
Japan
India
India
USSR
Turkey
Turkey
Kenya
USSR
Turkey
NSSL
P.R. China
Iran
Turkey
Turkey
India
Turkey
P.R. China
India
India
Puerto Rico
Iran
Turkey
Turkey
Denmark
USSR
Fruit yieldy
North Carolinaz
Iowaz
167
--175
139
182
138
159
156
112
202
162
149
162
137
--150
141
159
153
137
121
162
147
--161
132
143
148
116
175
--145
138
152
78
177
--143
54
228
140
140
139
140
152
118
150
128
145
133
138
139
HORTSCIENCE, VOL. 35(6), OCTOBER 2000
Table 3. Continued.
Cultigen name
PI 344442
PI 172846
PI 205995
PI 263083
PI 390953
Ansansky
Producer
PI 354952
PI 418963
PI 308916
PI 288992
PI 357855
PI 167134
PI 175690
PI 222244
PI 175696
PI 113334
Shamrock Resistant
PI 183231
Pixie
PI 263047
PI 169393
PI 419108
PI 169378
PI 285605
PI 226510
PI 436648
PI 279465
Seed sourcez
Iran
Turkey
Sweden
P.R. China
USSR
NSSL
NSSL
Denmark
P.R. China
USSR
Hungary
Yugoslavia
Turkey
Turkey
Iran
Turkey
P.R. China
NSSL
Egypt
NSSL
USSR
Turkey
P.R. China
Turkey
Poland
Iran
P.R. China
Japan
Fruit yieldy
North Carolinaz Iowaz
173
86
149
127
132
146
122
151
88
152
136
--144
127
108
162
141
127
116
151
130
137
103
163
147
118
125
140
115
149
132
132
130
134
173
91
151
113
130
133
131
132
127
136
134
128
135
127
133
128
125
135
112
147
121
155
1143
BREEDING, CULTIVARS, ROOTSTOCKS, & GERMPLASM RESOURCES
Table 3. Continued.
Cultigen name
PI 137844
PI 105340
PI 432873
PI 478365
PI 175693
PI 118279
PI 181753
PI 222243
PI 360939
PI 419010
PI 179676
PI 164950
PI 171607
PI 466922
PI 206425
PI 339250
PI 169304
Long of Keschmet
PI 422176
PI 288237
PI 114339
PI 279468
PI 165499
PI 271328
PI 271326
Snows Pickling
PI 164951
PI 422191
Regal
PI 211988
PI 275410
PI 432875
PI 171613
PI 390247
PI 342951
PI 172843
PI 432889
PI 271754
PI 221440
PI 432848
PI 326594
PI 271753
PI 169398
PI 177359
PI 211982
PI 169392
PI 175683
PI 432850
Gy 4
PI 400270
PI 283900
PI 204567
PI 164819
PI 172841
PI 422168
PI 177364
PI 302443
PI 204568
PI 326597
PI 174166
PI 422179
Tiny Dill
PI 249561
PI 220860
PI 356809
PI 458852
PI 285609
PI 137836
PI 174170
PI 103049
PI 227207
PI 432894
PI 176951
PI 262974
PI 165509
1144
Table 3. Continued.
Seed sourcez
Iran
P.R. China
P.R. China
P.R. China
Turkey
Brazil
Syria
Iran
Netherlands
P.R. China
India
Turkey
Turkey
USSR
Turkey
Turkey
Turkey
NSSL
Czechoslovakia
Egypt
Japan
Japan
India
India
India
NSSL
Turkey
Czechoslovakia
Checkx
Iran
Netherlands
P.R. China
Turkey
Japan
Denmark
Turkey
P.R. China
Netherlands
Afghanistan
P.R. China
Hungary
Netherlands
Turkey
Turkey
Iran
Turkey
Turkey
P.R. China
Checkx
Japan
Czechoslovakia
Turkey
India
Turkey
Czechoslovakia
Iraq
P.R. China
Turkey
Hungary
Turkey
Czechoslovakia
NSSL
Thailand
Korea
USSR
USSR
Poland
Iran
Turkey
P.R. China
Japan
P.R. China
Turkey
India
India
Fruit yield
North Carolinaz
146
129
99
123
127
136
141
127
105
134
88
130
132
118
138
151
159
100
122
125
118
96
117
118
104
111
123
148
117
111
118
126
110
125
123
148
149
127
117
132
128
119
126
122
118
130
141
123
99
145
123
122
123
121
117
164
131
119
129
118
109
134
110
110
130
136
121
142
125
124
115
129
125
122
92
y
Iowaz
112
129
174
138
130
121
116
130
163
120
168
125
123
141
117
103
95
136
133
128
134
156
135
134
148
141
128
92
135
140
133
124
140
--126
101
87
121
129
115
119
128
121
125
127
115
104
122
157
87
121
122
120
123
128
79
112
124
114
124
157
107
131
131
111
98
--99
115
117
125
111
115
118
148
Cultigen name
PI 422173
PI 264668
PI 193496
PI 339247
PI 196289
PI 355052
PI 478367
Texas Long
PI 267942
PI 169385
PI 169403
PSI
PI 263080
PI 181910
PI 478364
PI 175694
PI 284699
PI 109484
PI 169328
PI 422167
PI 264230
PI 234517
PI 422184
PI 314426
PI 188749
PI 227664
PI 200815
PI 179921
PI 344349
PI 181756
PI 357862
PI 172852
PI 193497
PI 422177
PI 432892
Sunny South
PI 285607
PI 390252
PI 176517
PI 182188
PI 169395
PI 351139
PI 174177
PI 339241
PI 181942
PI 269481
PI 105263
PI 169401
PI 357841
PI 451975
PI 137856
PI 487424
PI 175695
PI 267943
PI 176521
Calypso
PI 174167
PI 181940
PI 248778
PI 285603
PI 183677
PI 137846
PI 137857
Early Green Cluster
PI 432865
PI 135345
PI 264228
PI 422174
PI 227209
PI 267741
PI 164816
PI 419079
PI 137848
PI 109482
PI 092806
Seed sourcez
Czechoslovakia
Germany
Ethiopia
Turkey
India
Israel
P.R. China
NSSL
Japan
Turkey
Turkey
NSSL
USSR
Syria
P.R. China
Turkey
Sweden
Turkey
Turkey
Czechoslovakia
France
U.S.–S.C.
Czechoslovakia
USSR
Egypt
Iran
Burma
India
Turkey
Lebanon
Yugoslavia
Turkey
Ethiopia
Czechoslovakia
P.R. China
NSSL
Poland
Japan
Turkey
Turkey
Turkey
USSR
Turkey
Turkey
Syria
Pakistan
Turkey
Turkey
Yugoslavia
Canada
Iran
P.R. China
Turkey
Japan
Turkey
Checkx
Turkey
Syria
Iran
Poland
Turkey
Iran
Iran
NSSL
P.R. China
Afghanistan
France
Czechoslovakia
Japan
Japan
India
P.R. China
Iran
Turkey
P.R. China
Fruit yieldy
North Carolinaz Iowaz
114
129
114
126
128
111
139
101
109
130
113
126
121
117
95
132
99
133
134
105
122
115
128
106
117
121
109
128
139
89
137
101
116
122
111
126
115
123
124
116
121
116
117
119
95
141
115
121
126
109
96
132
114
129
116
119
124
111
127
107
144
77
112
122
115
119
109
125
120
114
131
95
124
109
105
151
131
103
119
115
94
151
114
120
121
112
125
108
125
107
117
115
107
125
108
124
118
114
120
110
125
106
116
--121
109
117
114
116
115
110
122
116
114
113
122
136
93
122
108
106
124
119
111
113
116
114
115
130
91
122
106
104
124
77
170
103
131
108
124
108
120
110
118
107
121
125
102
101
126
HORTSCIENCE, VOL. 35(6), OCTOBER 2000
conducted using recommended horticultural
practices (Hughes et al., 1983; Schultheis,
1990). Fertilizer was incorporated before
planting at a rate of 90N–39P–74K kg·ha–1,
with an additional 34 kg·ha–1 N applied at the
vine tip-over stage. Curbit® [(ethalfluralin Nethyl-N-(2-methyl-2-propenyl)-2,6-dinitro-4(trifluoromethyl)benzenamine)] was applied
for weed control. Irrigation was applied when
needed for a total (irrigation plus rainfall) of
25 to 40 mm per week. ‘Sumter’ pollenizer
was planted on the sides of the plots to provide pollen.
Plots were disease free through once-over
harvest stage (26 June) when oversized fruit
averaged 15% across all the plots in the field.
Although the usual index for yield evaluation
for testing populations in our breeding pro-
gram is 10%, we used a 15% index in this
study to allow late-flowering cultigens to
produce fruit.
Cultural practices. In North Carolina,
seeds were planted on raised, shaped beds 1.5
m apart. Plots were 1.2 m long × 1.5 m wide
with 1.2-m alleys at each end. Guard rows
were planted on the outside of the field, and
at the end of each row. Plots were planted
with 14 seeds on 12 May and thinned to a
uniform stand of 10 plants per plot on 29
May.
In Iowa, seeds were planted in beds 1.5 m
apart. Plots were 6.0 m long and 1.5 m wide
with 1.5-m alleys at each end. Guard rows
were planted on the outside of the field, and
at the end of each row using ‘Sumter’ as a
pollenizer. The plots were planted with 25
Table 3. Continued.
Cultigen name
PI 483344
PI 263046
Dasher II
PI 209064
PI 264667
PI 414157
PI 171602
PI 288238
PI 324239
PI 344434
PI 458849
PI 285606
PI 169384
PI 172845
PI 436672
PI 212233
PI 181874
PI 356832
PI 176957
PI 109481
PI 172849
PI 289698
PI 422171
PI 169396
PI 435946
PI 171604
PI 167389
PI 174174
PI 263048
PI 255938
PI 209068
PI 379278
PI 264665
PI 267746
PI 172847
Clinton
PI 392292
PI 176525
PI 422172
PI 255933
PI 172848
PI 211977
PI 171612
PI 211962
PI 344351
Boston Pickling
PI 419183
PI 263082
PI 390258
PI 308915
Robin
PI 178886
seeds on 12 May and thinned to a uniform
stand of 20 plants per plot.
Cultigens evaluated. In this experiment,
761 cultigens (746 PI accessions and 15 check
cultivars and breeding lines) were evaluated.
Accessions designated with a PI number were
obtained from the USDA germplasm
collection in Ames, Iowa. Cultigens with an
NSSL seed source were obtained from the
National Seed Storage Laboratory in Fort
Collins, Colo. The cultigens originated from
44 different countries. Countries with the
most cultigens were Turkey (166), the
People’s Republic of China (P.R. China) (85),
Iran (64), the former Yugoslavia (63), India
(47), Japan (44), the former Soviet Union
(USSR) (37), the former Czechoslovakia (27),
The Netherlands (19), United States (16), and
Table 3. Continued.
z
Seed source
Korea
USSR
Checkx
U.S.–Ohio
Germany
U.S.–Ore.
Turkey
Egypt
Sweden
Iran
USSR
Poland
Turkey
Turkey
P.R. China
Japan
Syria
Netherlands
Turkey
Turkey
Turkey
Australia
Czechoslovakia
Turkey
USSR
Turkey
Turkey
Turkey
USSR
Netherlands
U.S.–Ohio
Yugoslavia
Germany
India
Turkey
N.C. State Univ.
USSR
Turkey
Czechoslovakia
Netherlands
Turkey
Iran
Turkey
Iran
Turkey
NSSL
P.R. China
P.R. China
Japan
USSR
NSSL
Turkey
Fruit yield
North Carolinaz
35
105
118
104
141
96
116
114
120
109
130
120
113
127
106
110
105
108
109
113
108
114
96
100
112
112
110
115
106
131
110
103
109
116
117
110
103
137
97
122
116
110
116
94
106
94
138
113
78
110
46
113
HORTSCIENCE, VOL. 35(6), OCTOBER 2000
y
z
Iowa
192
122
109
123
85
125
110
113
106
117
95
106
--98
122
115
120
116
115
112
116
111
136
124
113
113
114
109
117
92
113
125
114
107
106
114
125
86
154
100
105
112
106
127
115
136
92
108
143
111
142
107
Cultigen name
Seed source
PI 279464
Japan
PI 224668
Korea
PI 432883
P.R. China
PI 172844
Turkey
PI 344353
Turkey
PI 390259
Japan
PI 343452
USSR
PI 169394
Turkey
PI 271331
India
PI 137853
Iran
PI 279463
Japan
PI 483342
Korea
PI 182190
Turkey
PI 436609
P.R. China
PI 418962
P.R. China
PI 391570
P.R. China
PI 339246
Turkey
PI 264664
Germany
PI 175689
Turkey
PI 344350
Turkey
PI 321006
Taiwan
PI 390269
Japan
PI 355053
Iran
PI 211978
Iran
Staygreen
NSSL
PI 419136
P.R. China
PI 368548
Yugoslavia
PI 419017
P.R. China
PI 182192
Turkey
PI 137835
Iran
PI 169388
Turkey
PI 369717
Poland
PI 173892
India
PI 357850
Yugoslavia
Giant White Arnstadt
NSSL
PI 106063
P.R. China
PI 390255
Japan
PI 257494
Iran
PI 283899
Czechoslovakia
PI 209065
U.S.–Ohio
PI 175680
Turkey
PI 263084
P.R. China
PR 39
NSSL
PI 257286
Spain
PI 432864
P.R. China
PI 357851
Yugoslavia
PI 211117
Israel
PI 211980
Iran
PI 209069
U.S.–Ohio
PI 357858
Yugoslavia
PI 288990
Hungary
PI 288996
Hungary
z
Fruit yieldy
North Carolinaz Iowaz
115
105
80
141
113
107
108
112
112
108
83
138
122
98
114
106
103
116
120
99
107
113
105
116
108
111
113
107
108
111
--109
126
92
95
124
117
101
100
118
113
104
97
121
101
117
132
85
101
120
122
96
84
145
123
87
110
107
117
100
106
112
111
104
95
122
115
102
--108
107
110
90
127
112
105
104
112
107
108
107
108
126
90
69
146
106
109
80
150
98
117
113
102
107
108
95
119
113
99
90
124
116
98
1145
BREEDING, CULTIVARS, ROOTSTOCKS, & GERMPLASM RESOURCES
Table 3. Continued.
Cultigen name
PI 288995
PI 376063
PI 171605
PI 401734
PI 288993
PI 172838
PI 432853
PI 169319
PI 169350
PI 175679
PI 172842
PI 267747
PI 167197
PI 419214
PI 183224
PI 212985
PI 246930
PI 435947
PI 267743
PI 167050
PI 164670
PR 27
PI 264226
PI 422198
PI 321007
PI 281448
PI 489754
PI 357842
PI 165046
Chicago Pickling
PI 338235
PI 390267
Nappa 63
PI 357852
PI 211983
PI 267745
PI 275412
PI 344435
PI 368550
PI 211985
PI 169386
PI 206043
PI 357838
PI 164952
PI 251520
PI 292010
PI 432877
PI 206954
PI 306179
Earliest of All
PI 418964
PI 422170
PI 257486
PI 169377
PI 179260
PI 262990
PI 372898
PI 267197
PI 432870
PI 344067
PI 419009
PI 171609
PI 249550
Favor II
PI 177363
PI 226509
PI 432878
PI 169383
PI 169382
PI 169389
PI 197086
PI 229309
PI 171606
PI 176522
PI 339245
1146
Table 3. Continued.
Seed sourcez
Hungary
Israel
Turkey
Puerto Rico
Hungary
Turkey
P.R. China
Turkey
Turkey
Turkey
Turkey
U.S.–Okla.
Turkey
Hong Kong
Egypt
India
Afghanistan
USSR
P.R. China
Turkey
India
NSSL
France
Czechoslovakia
Taiwan
Korea
P.R. China
Yugoslavia
Turkey
NSSL
Turkey
Japan
NSSL
Yugoslavia
Iran
Brazil
Netherlands
Iran
Yugoslavia
Iran
Turkey
Puerto Rico
Yugoslavia
Turkey
Iran
Israel
P.R. China
Turkey
Poland
NSSL
P.R. China
Czechoslovakia
P.R. China
Turkey
Turkey
Netherlands
Netherlands
P.R. China
P.R. China
Turkey
P.R. China
Turkey
Iran
NSSL
Syria
Iran
P.R. China
Turkey
Turkey
Turkey
India
Iran
Turkey
Turkey
Turkey
Fruit yield
North Carolinaz
95
119
77
123
108
122
108
112
110
117
105
118
134
121
125
107
110
89
98
99
83
92
86
78
103
99
124
100
114
118
98
114
92
101
101
88
111
113
78
115
110
97
73
122
100
103
93
105
98
93
108
92
103
80
110
110
83
115
134
126
104
89
99
98
112
105
--120
102
112
99
108
109
100
104
y
Iowaz
120
89
137
91
106
92
105
101
103
96
108
95
79
91
88
105
103
132
115
111
129
120
126
134
109
113
78
111
100
82
113
93
119
110
110
122
100
93
133
95
101
113
137
88
110
107
129
--112
116
100
117
106
129
99
99
147
94
74
82
105
119
109
110
96
103
104
87
105
95
108
99
98
105
102
Cultigen name
Seed sourcez
PI 321010
Taiwan
PI 227208
Japan
PI 357839
Yugoslavia
PI 172851
Turkey
PI 269480
Pakistan
PI 343451
USSR
Arlington Wt. Spine
NSSL
PI 174164
Turkey
PI 274902
Great Britain
Sprint 440
Checkx
PI 137847
Iran
PI 264229
France
PI 432861
P.R. China
PI 173674
Turkey
PI 217644
India
PI 293923
U.S.–S.C.
PI 164734
India
PI 169353
Turkey
PI 176519
Turkey
PI 344444
Iran
PI 176952
Turkey
PI 344439
Iran
PI 204569
Turkey
PI 176516
Turkey
PI 183445
India
PI 171600
Turkey
PI 390256
Japan
PI 167198
Turkey
PI 432866
P.R. China
PI 169315
Turkey
PI 171611
Turkey
PI 293432
Lebanon
PI 326595
Hungary
PI 285608
Poland
PI 172840
Turkey
PI 422190
Czechoslovakia
PI 228344
Iran
National Pickling
NSSL
PI 489752
P.R. China
PI 182189
Turkey
PI 432886
P.R. China
PI 458847
USSR
PI 357859
Yugoslavia
PI 220790
Afghanistan
M 21
Checkx
PI 304803
U.S.–N.Y.
PI 419041
P.R. China
PI 192940
P.R. China
PI 211943
Iran
PI 482464
Zimbabwe
Model
NSSL
PI 422188
Czechoslovakia
PI 179263
Turkey
PI 211975
Iran
PI 233932
Canada
PI 137845
Iran
PI 169402
Turkey
PI 339244
Turkey
PI 163221
India
PI 176953
Turkey
PI 368556
Yugoslavia
PI 344348
Turkey
PI 326598
Hungary
Gy 5
Checkx
PI 356833
Great Britain
Palmetto
NSSL
Straight 8
NSSL
PI 227210
Japan
PI 391573
P.R. China
PI 227013
Iran
PI 222782
Iran
PI 167079
Turkey
PI 261609
Spain
PI 263079
USSR
PI 267086
USSR
Fruit yieldy
North Carolinaz Iowaz
87
119
104
102
118
88
96
110
115
92
112
94
117
89
109
99
115
91
103
102
103
102
99
106
111
97
117
88
109
96
129
76
101
103
110
94
102
--118
86
118
86
98
107
122
83
111
93
90
114
111
93
116
81
107
97
103
100
103
100
106
98
102
--110
93
111
92
86
117
87
117
90
113
112
87
102
101
108
95
91
108
101
--102
101
117
85
108
94
89
113
--101
91
111
103
97
107
92
105
95
97
106
111
90
87
114
101
99
106
94
112
88
74
126
88
113
75
125
92
112
103
97
90
109
92
108
122
78
117
83
89
110
100
--100
99
86
113
111
87
108
90
98
100
96
102
67
131
HORTSCIENCE, VOL. 35(6), OCTOBER 2000
Afghanistan (14). The cultigens designated as
checks were tested as the cultigens per se (not
their F1 with Gy 14).
The 761 cultigens consisted of PI accessions, obsolete cultivars, current cultivars, and
experimental inbreds and hybrids. In order to
produce gynoecious hybrids, the cultigens were
crossed with Gy 14, a popular, publicly-released, gynoecious pickling cucumber inbred.
All crosses were made by hand at the Horticultural Science greenhouses, Raleigh, during the
previous year. The hybrids could then be evaluated for yield regardless of sex expression of the
male parent. In order to represent each cultigen
properly, each hybrid was made up from a
mixture of seeds obtained by crossing several
plants of each accession with Gy 14.
Traits measured. Data were collected as
plot means, and consisted of number of plants
per plot, and number of early, total, and cull
fruit per plot in both locations. Early fruit were
the number of oversized fruit at harvest (>51
mm diameter for pickles and >60 mm for slicing cucumber). The number of marketable fruit
was calculated as total fruit minus culls. Cull
fruits were misshapen (crooked or nubbined).
Data for marketable fruits were not recorded in
Iowa.
Data analysis. The experiment was a randomized complete-block design with 761 cultigens and three replications at two locations.
Data were analyzed using GLM and CORR
procedures of SAS (SAS Institute, Cary, N.C.).
Yield traits were expressed as thousands of
fruit/ha for ease of comparison of yield over
locations, and with previously published studies.
The data were analyzed using actual yield
and corrected yield for both locations. Plots
Table 3. Continued.
Cultigen name
PI 211979
PI 163214
PI 169352
PI 169400
PI 222987
PI 357847
PI 177360
PI 390241
PI 169351
PI 288994
PI 458848
PI 379285
PI 222986
PI 220791
PI 401733
PI 306785
PI 436610
PI 292012
PI 414158
PI 458846
PI 172839
PI 355055
PI 304805
PI 368558
PI 339248
PI 275411
PI 255936
PI 251519
PI 292011
PI 220171
PI 167358
PI 357863
PI 344441
PI 174173
PI 277741
Gy 2
PI 390952
PI 176956
PI 432860
PI 422186
PI 222783
PI 137839
PI 263081
PI 135123
PI 200818
PI 344347
PI 176524
PI 414159
PI 178884
PI 165506
PI 174160
with a stand count (plant number) of <50% of
the expected 20 plants were eliminated from the
statistical analysis. Plots with stand counts
ranging from 50% to 75% were corrected according to Cramer and Wehner (1998), using
the formula: corrected yield = (total yield/stand
count) × 20. The corrected yield and total yield
were then standardized to a mean of 100 and a
SD of 30 (a SD of 30 would give a range of 0 to
200 if individuals were within three SD of the
mean) for each location and replication using
the STANDARD procedure of SAS. Standardization permitted comparison of cultigens when
some plots were missing from locations or
replications. The most useful traits are those
where the range/LSD is large. If the range/LSD is
small (<1), then the best cultigen cannot be
statistically separated from the worst cultigen
in the test.
Table 3. Continued.
Seed source
Iran
India
Turkey
Turkey
Iran
Yugoslavia
Turkey
Japan
Turkey
Hungary
USSR
Yugoslavia
Iran
Afghanistan
Puerto Rico
Canada
P.R. China
Israel
U.S.–Hawaii
USSR
Turkey
Iran
U.S.–N.Y.
Yugoslavia
Turkey
Netherlands
Netherlands
Iran
Israel
Afghanistan
Turkey
Yugoslavia
Iran
Turkey
Netherlands
Checkx
USSR
Turkey
P.R. China
Czechoslovakia
Iran
Iran
P.R. China
New Zealand
Burma
Turkey
Turkey
U.S.–Hawaii
Turkey
India
Turkey
z
Fruit yield
North Carolinaz
87
94
95
89
94
94
101
76
93
89
82
101
96
87
76
112
116
92
100
101
95
99
66
128
103
120
100
90
97
103
110
103
106
109
108
94
104
94
99
105
94
85
94
85
87
110
89
79
114
80
96
HORTSCIENCE, VOL. 35(6), OCTOBER 2000
y
z
Iowa
111
103
102
108
103
103
96
121
104
107
145
93
100
114
105
83
88
106
93
91
99
95
128
66
91
73
94
103
96
87
83
87
87
84
85
98
88
98
92
87
98
106
97
106
105
81
101
111
75
110
94
z
Cultigen name
Seed source
PI 432862
P.R. China
PI 419135
P.R. China
PI 267744
P.R. China
PI 432857
P.R. China
PI 206955
Turkey
PI 296387
Iran
PI 267088
USSR
PI 223437
Afghanistan
PI 436673
P.R. China
Early Fortune
NSSL
PI 326596
Hungary
PI 357844
Yugoslavia
PI 212599
Afghanistan
PI 390248
Japan
PI 373918
England
PI 357846
Yugoslavia
PI 169387
Turkey
PI 390239
Japan
PI 167043
India
PI 432858
P.R. China
PI 264666
Germany
PI 169390
Turkey
PI 167052
Turkey
PI 264231
France
PI 164173
India
PI 344433
Iran
PI 390251
Japan
PI 357865
Yugoslavia
PI 422182
Czechoslovakia
PI 368551
Yugoslavia
PI 338234
Turkey
PI 211984
Iran
PI 344432
Iran
PI 211589
Afghanistan
PI 370448
Yugoslavia
York State Pickle
NSSL
PI 175691
Turkey
PI 390250
Japan
PI 227235
Iran
PI 217946
Pakistan
PI 255935
Netherlands
PI 344443
Iran
PI 321011
Taiwan
PI 267935
Japan
PI 319216
Un. Arab. Repub.
PI 321009
Taiwan
PI 422181
Czechoslovakia
PI 165029
Turkey
PI 164284
India
PI 135122
New Zealand
PI 283902
Czechoslovakia
Fruit yieldy
North Carolinaz Iowaz
92
99
110
72
91
98
86
103
110
79
67
122
94
94
89
99
110
79
97
91
96
92
105
83
107
74
97
87
89
100
--94
98
89
75
121
101
86
97
90
94
92
83
103
89
97
99
87
88
98
91
95
41
118
107
78
101
84
96
87
102
83
85
99
88
97
104
81
97
84
94
86
104
84
82
108
85
99
91
93
113
71
109
74
96
87
100
84
101
82
94
88
70
123
93
90
84
98
81
101
101
81
1147
BREEDING, CULTIVARS, ROOTSTOCKS, & GERMPLASM RESOURCES
Table 3. Continued.
Table 3. Continued.
y
Cultigen name
PI 222099
PI 204692
PI 179259
PI 283901
PI 279467
PI 164743
PI 169381
PI 257487
PI 163217
PI 357868
PI 222985
PI 357867
PI 176954
PI 220789
PI 175681
PI 432867
PI 285604
PI 390265
PI 357857
PI 458850
PI 176924
PI 390261
PI 339243
PI 390240
PI 204690
PI 255937
PI 163213
PI 390262
PI 390264
PI 306180
PI 109275
PI 368549
PI 171608
PI 209067
PI 357845
PI 458856
PI 271334
PI 197085
PI 422169
PI 357836
PI 422200
PI 209066
PI 176523
PI 288991
PI 109483
PI 357834
PI 288332
PI 432879
PI 177361
PI 264227
PI 249562
PI 250147
PI 218199
PI 321008
PI 391569
PI 173893
PI 178887
PI 296120
PI 357840
PI 220169
PI 338236
PI 261608
PI 197087
PI 218036
PI 390246
PI 181752
PI 314425
PI 211986
SMR 58
PI 223841
PI 478366
Gy 14
PI 357833
Sumter
1148
Seed sourcez
Afghanistan
Turkey
Turkey
Czechoslovakia
Japan
India
Turkey
P.R. China
India
Yugoslavia
Iran
Yugoslavia
Turkey
Afghanistan
Turkey
P.R. China
Poland
Japan
Yugoslavia
USSR
Turkey
Japan
Turkey
Japan
Turkey
Netherlands
India
Japan
Japan
Poland
Turkey
Yugoslavia
Turkey
U.S.–Ohio
Yugoslavia
USSR
India
India
Czechoslovakia
Yugoslavia
Czechoslovakia
U.S.–Ohio
Turkey
Hungary
Turkey
Yugoslavia
India
P.R. China
Turkey
France
Thailand
Pakistan
Lebanon
Taiwan
P.R. China
India
Turkey
Egypt
Yugoslavia
Afghanistan
Turkey
Spain
India
Iran
Japan
Syria
USSR
Iran
Checkx
Philippines
P.R. China
Checkx
Yugoslavia
Checkx
Fruit yield
North Carolinaz Iowaz
94
104
115
74
70
90
78
84
97
78
84
82
67
97
80
92
102
76
104
108
93
45
68
48
101
75
89
101
65
67
84
--97
88
91
92
96
72
63
90
68
49
90
85
73
80
78
64
112
94
51
96
90
97
95
73
89
97
62
80
71
84
72
100
54
108
89
84
80
91
92
86
62
67
88
78
67
108
112
92
104
100
84
102
94
98
113
83
100
87
77
103
79
80
86
133
110
151
77
99
89
70
112
110
95
89
80
--85
83
76
104
113
87
101
125
84
89
101
94
95
110
70
79
123
77
83
79
81
95
82
75
101
92
100
87
99
63
132
62
78
85
89
77
72
81
106
100
Cultigen name
Everbearing
PI 357837
PI 285610
PI 368557
PI 419078
PI 137851
PI 357849
PI 458853
PI 432863
PI 211967
PI 269482
PI 432890
PI 432851
PI 432893
PI 436608
PI 358814
Muronium
PI 368560
PI 175950
PI 202801
PI 267742
PI 175692
Delicatesse
PI 390954
PI 207476
PI 176526
PI 357832
Davis Perfect
PI 372587
PI 432888
PI 212059
PI 432859
PI 481616
PI 263078
Addis
PI 169334
PI 206953
PI 422196
White Wonder
PI 390245
PI 279466
Delcrow
MR 200
PI 357831
PI 344438
Shogoin
PI 432895
PI 197088
Redlands
PI 390257
PI 390266
PI 163223
PI 390260
PI 344440
PI 481614
PI 255934
PI 357860
PI 344352
PI 390244
PI 357830
PI 222720
PI 357864
Wautoma
PI 296121
PI 357854
PI 263049
PI 418989
PI 368552
PI 368555
WS Davis Perfect
PI 432855
PI 211728
PI 214049
PI 432885
Seed sourcez
NSSL
Yugoslavia
Poland
Yugoslavia
P.R. China
Iran
Yugoslavia
USSR
P.R. China
Iran
Pakistan
P.R. China
P.R. China
P.R. China
P.R. China
Malaysia
NSSL
Yugoslavia
Turkey
Syria
P.R. China
Turkey
NSSL
USSR
Afghanistan
Turkey
Yugoslavia
NSSL
Netherlands
P.R. China
Greece
P.R. China
Bhutan
USSR
Checkx
Turkey
Turkey
Czechoslovakia
NSSL
Japan
Japan
NSSL
NSSL
Yugoslavia
Iran
NSSL
P.R. China
India
Australia
Japan
Japan
India
Japan
Iran
Bhutan
Netherlands
Yugoslavia
Turkey
Japan
Yugoslavia
Iran
Yugoslavia
Checkx
Egypt
Yugoslavia
USSR
P.R. China
Yugoslavia
Yugoslavia
NSSL
P.R. China
Afghanistan
India
P.R. China
Fruit yieldy
North Carolinaz Iowaz
70
89
86
83
72
83
72
41
80
79
85
91
60
86
86
74
78
68
70
81
70
112
67
79
90
91
110
--88
54
52
98
--58
50
84
88
76
56
47
84
73
86
62
70
79
102
69
47
72
40
70
56
62
.
77
73
66
56
49
63
3
42
52
64
56
19
22
32
72
90
75
65
51
97
78
81
--101
--95
125
87
87
80
66
116
79
77
104
86
108
93
81
92
50
95
83
70
73
51
80
67
97
107
53
79
100
108
73
69
81
100
109
72
84
65
92
83
72
59
83
106
82
99
81
93
93
74
72
74
80
98
97
81
95
97
92
80
87
97
119
129
65
49
65
74
87
HORTSCIENCE, VOL. 35(6), OCTOBER 2000
Retest. Eight high-yielding and four lowyielding cultigens were retested along with
four checks at the Horticultural Crops Experiment Station, Clinton, in 1989. In the retest,
the cultigens per se were tested rather than
their hybrids with Gy 14. Seeds were planted
on raised, shaped beds 1.5 m apart. Plots were
1.2 m long × 1.5 m wide with 1.2-m alleys at
each end. The guard rows were planted on the
outside of the field, and at the end of each row
using ‘Sumter’ as a monoecious pollinizer.
The experiment was a randomized complete-block design with 16 cultigens and eight
replications. Plots were harvested six times
(twice each week for 3 weeks) during Spring
1989, number and weight of marketable and
cull fruit were recorded. Plant stand and flower
count data were taken 3 and 5 weeks after
planting. Number of pistillate and staminate
nodes at the first five nodes of five plants were
counted on each plot. Data were analyzed
using the GLM procedure of SAS.
Results and Discussion
The cultigens produced hybrids differing
significantly for all the traits evaluated
(Table 1). We detected significant differences
between the two locations for total yield, corrected total yield, and percentage of early fruit.
Cultigen × location interaction was significant
(P < 0.01) for all the traits that were evaluated
at both locations. The location effect was
removed by standardizing the data to form
standardized total and standardized corrected
total yield.
The traits that were most reliable over both
locations were total yield, corrected total yield,
standardized total yield, and standardized cor-
rected total yield. Correction for plant stand
improved the data by reducing the CV relative
to that for corrected total yield. Therefore, data
are presented as the standardized corrected
total yield for all cultigens over both locations.
In the analysis of variance, mean squares for
location and cultigen by location interaction
were highly significant, so standardized corrected total yields for cultigens were reported
for each location, rather than the mean standardized corrected total yields over both locations. This was consistent with the findings of
Wehner (1987b) who reported that genotype
and environment were important sources of
variation for yield in once-over harvest trials.
The cultigen mean square was significant
for all traits evaluated, indicating that some
cultigens yielded significantly more than others. The corrected yield had a better (smaller)
CV, and a better (larger) range/LSD than did
total yield. Therefore, we decided to choose
corrected total yield over total yield (Table 1).
An additional benefit was that corrected total
yield took into consideration the differences in
plant stand. We decided to present yield as
standardized corrected total because it had a
better (lower) CV, better (lower) LSD, and a
better (higher) range/LSD than did corrected
total yield. The other advantage of using standardized corrected total yield was that it permitted comparison of cultigens even when
some were missing from some replications.
We observed highly significant differences
for location and location by cultigen interaction for percentage of early fruit (Table 1). The
percentage of early fruit for Iowa had a mean
of 100, a range of 30, and a range/LSD of 3. The
percentage of early fruit for North Carolina
had a mean of 15, a range of 63, and range/LSD
Table 3. Continued.
Cultigen name
PI 422180
PI 206952
Pacer
PI 372893
PI 379280
PI 205181
PI 344437
PI 432896
PI 271327
PI 357843
PI 481617
PI 279469
PI 212896
PI 422192
PI 379287
PI 265887
PI 489753
PI 390268
PI 357869
PI 432871
PI 368553
PI 357848
PI 175111
PI 357835
PI 175688
PI 370449
PI 379281
PI 390951
PI 357856
of 3. Marketable yield was recorded only in
North Carolina.
In general, correlations between locations
for the yield traits were low (Table 2);
r values for total yield, standardized total
yield, corrected total yield, and standardized
corrected total yield were 0.33, 0.34, 0.21, and
0.23, respectively. Although the correlations
for standardized corrected total yield were
slightly lower than those for total and standardized total yield, standardized corrected
yield was more useful because it was corrected
for both plant stand and location.
Standardized corrected total yield, which
was the only trait reported for the 761
gynoecious hybrids, differed significantly in
North Carolina and Iowa (Table 3). Several PI
accessions produced high-yielding hybrids
with Gy 14. There were 284 cultigens whose
hybrids yielded more than the standard check
‘Calypso’. Thus, yield might be improved by
using the high performing cultigens identified
in this study. The highest yielding hybrids at
both locations were produced using the following paternal parents: PI 422185, PI 390253,
PI 175120, PI 173889, PI 267087, PI 175686,
PI 178888, PI 385967, PI 458851, and PI
171601. The highest yielding hybrids at North
Carolina were produced using the following
paternal parents: PI 175120, PI 390253, PI
344442, ‘Shamrock’, PI 422185, PI 177364,
PI 175686, PI 178888, PI 226461, and PI
173889. The highest yielding hybrids at Iowa
were produced using the following paternal
parents: PI 179678, PI 267087, PI 483344, PI
391568, PI 171610, PI 432873, PI 422174, PI
179676, PI 360939, and PI 357855.
A majority of the cultigens that were classified as high or low yielders in the germ-
Table 3. Continued.
Seed sourcez
Fruit yieldy
North Carolinaz Iowaz
Czechoslovakia
Turkey
Harris-Moran
Netherlands
Yugoslavia
Turkey
Iran
P.R. China
India
Yugoslavia
Bhutan
Japan
India
Czechoslovakia
Yugoslavia
Netherlands
P.R. China
Japan
Yugoslavia
P.R. China
Yugoslavia
Yugoslavia
India
Yugoslavia
Turkey
Yugoslavia
Yugoslavia
USSR
Yugoslavia
HORTSCIENCE, VOL. 35(6), OCTOBER 2000
20
103
19
66
72
50
86
58
40
59
–1
44
8
64
51
62
68
55
60
49
34
51
43
51
33
49
53
25
28
117
33
117
70
64
84
54
82
93
72
99
86
122
66
78
67
59
70
65
88
89
72
83
65
92
68
61
99
94
Cultigen name
PI 183127
PI 458855
PI 370450
Magnolia
PI 379283
M 27
PI 370447
PI 183056
PI 379284
PI 379282
PI 432874
Stono
WI 2757
Marketmore 76
Cubit
PI 368554
PI 357853
PI 368559
Mean
LSD (5%)
CV
Range
Range/LSD
Seed sourcez
India
USSR
Yugoslavia
NSSL
Yugoslavia
Checkx
Yugoslavia
India
Yugoslavia
Yugoslavia
P.R. China
NSSL
Checkx
Checkx
NSSL
Yugoslavia
Yugoslavia
Yugoslavia
Fruit yieldy
North Carolinaz Iowaz
17
57
33
51
50
68
30
3
34
42
34
--14
18
11
18
9
12
100
47
29
183
4
92
46
80
----17
53
104
55
42
49
38
67
49
45
36
56
57
100
27
17
172
6
z
Some countries listed as the origin of some accessions (e.g., Czechoslovakia, USSR, Yugoslavia) now no longer exist as political units.
y
Data are means of three replications.
x
For the checks, yield was measured per se, rather than as combining
ability with Gy 14.
1149
BREEDING, CULTIVARS, ROOTSTOCKS, & GERMPLASM RESOURCES
Table 4. Fruit yield traitsz for the 17 cultigens retested at Clinton, N.C. (cultigens ranked by total fruit
number).
Seed
Yield
Cultigen
source
class
PI 169397
Turkey
High
Producer
NSSL
High
Regal
Harris Moran
Check
Poinsett 76
Petoseed
Check
PI 342950
Denmark
High
PI 175696
Turkey
High
Wautoma
USDA–Wisc.
Low
PI 174172
Turkey
High
Wis. SMR 18
Northrup King Check
PI 178888
Turkey
High
PI 206425
Turkey
High
Pacer
Harris Moran
Low
Marketmore 76
Asgrow Seed
Check
PI 339250
Turkey
High
PI 357853
Yugoslavia
Low
Mean
CV (%)
LSD (5%)
Range
Range/LSD
z
Data are means of eight replications.
y
Nodes not pistillate or staminate were barren.
Total fruit/ha
No.
Wt
(1000s) (Mg)
915
67
662
58
646
74
615
66
600
40
586
74
512
45
508
51
484
54
458
49
430
33
382
30
355
21
348
60
274
25
518
50
47
90
244
17
641
53
3
3
plasm screening study ranked as predicted in
the retest (Table 4), despite the fact that the
retest was conducted using the cultigens per
se and not combining ability with Gy 14. Two
exceptions were ‘Wautoma’ and PI 339250,
which were low or high yielding when crossed
with Gy 14 in the germplasm screening, but
were ranked at the middle and bottom in the
retest study, respectively. Thus, yield of a
cultigen tested as a gynoecious hybrid (in the
germplasm screening), is similar to yield of
the cultigen per se with few exceptions
Once-over harvest yield might be improved using the highest yielding cultigens
crossed to inbreds such as Gy 14. The top
yielding cultigens could also be intercrossed
to form a population from which to develop
high yielding inbreds. A useful future study
would be to screen the germplasm collection
using ethrel to convert all cultigens to a
gynoecious form for yield testing.
1150
Fruit
Marketable Cull
(%)
(%)
84
16
91
9
91
9
87
13
90
10
83
17
95
5
86
14
87
13
80
20
94
6
91
9
89
11
81
19
91
9
88
12
7
49
6
6
15
15
3
3
Nodesy
Pistillate Staminate
(%)
(%)
6
89
29
66
73
21
37
49
9
86
7
90
1
92
5
87
8
85
7
87
0
90
10
77
1
89
12
84
0
90
14
79
55
1
8
10
73
71
9
7
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