Results of New Cultivar Selection Trials for Lemon in
Arizona – 2006-071
Glenn C. Wright
Department of Plant Sciences, U. of A., Yuma Mesa Agriculture Center, Yuma, AZ
Abstract
Three lemon cultivar selection trials are being conducted at the Yuma Mesa
Agriculture Center in Somerton, AZ. Data from these trials suggest that
‘Limonero Fino 49’ and ‘Cascade Eureka ’selections may be a suitable
alternative for the varieties most commonly planted in Southwest Arizona today.
‘Femminello’ and ‘Villafranca’ might also be planted on an experimental basis
Introduction
The Arizona lemon industry has historically relied on a small number of lemon cultivar selections. In the 1950’s, the
industry was established with ‘Desert Lisbon’, however within a few years, ‘Desert Lisbon’ was eclipsed in
popularity by ‘Frost Nucellar Lisbon’ the only nucellar clonal selection of the ‘Lisbon’ cultivar. Other minor
selections of ‘Lisbon’ that were planted in Arizona from the 1960’s through the 1980’s included ‘Monroe’, ‘Prior’,
and ‘Rosenberger’. Beginning in the late 1980’s, new plantings were established using ‘Limoneira 8A Lisbon’.
More recently, ‘Corona Foothills Lisbon’ is increasingly popular. ‘Allen Eureka’ has also been occasionally planted
in Arizona.
All of these represent clonal selections of outstanding trees that were then propagated. Typically, they are identified
by their originator or place of origin, and are valuable to Arizona growers because of their high vigor, high
productivity, precocity (trees bear at an early age), earliness (a high percentage of the fruit can be harvested before 1
November), short thorns and good fruit quality. When a commonly grown lemon cultivar selection is gradually
replaced in the industry, the new selection typically is improved in one of these characteristics. Sometimes a cultivar
selection may be replaced because of a negative characteristic. Such was the case with ‘Frost Nucellar Lisbon’
which appears to be susceptible to brown heartwood rot.
From the late 1980’s, to the early 1990’s, Arizona lemon growers have received their information about new cultivar
selections through word of mouth or from nursery sources, since there were no trials planted in the state. With this in
mind, we have planted three new lemon cultivar selection trials in 1995, 1997 and 1998, all located at the Yuma
Mesa Agricultural Center. These trial results are presented here.
1 1
The author wishes to thank Mr. Phillip Tilt, Mr. Marco Peña, Mr. Arturo Moreno, and the Yuma Mesa Fruit
Grower’s Association for their assistance in completing this project. The author would also like to thank the Arizona
Citrus Research Council for supporting this research. This is a partial final report for project 2006-03 – Citrus
rootstock and cultivar breeding and evaluation for the Arizona citrus industry – 2006-07.
Citrus Research Report (P-153) October 2007
27
Materials and Methods
1995 Lemon Cultivar Selection Trial. This trial, at first comprising 10 cultivar selections was established in March
1995 in Block 17 (Foundation Block) of the Yuma Mesa Agricultural Center, near Yuma, Arizona. An additional
cultivar selection was planted in 1997. As it exists within the citrus variety collection, it is not a large trial, nor is it
replicated. The experimental area was laser leveled and fumigated prior to planting. Trees were planted on a 10-m x
10-m spacing. Three to five trees of each cultivar selection were planted. This trial contains the following
selections, all on C. volkameriana rootstock:
‘Allen Eureka’ – The most common and popular ‘Eureka’ selection planted in Arizona. Originated in Santa
Paula, CA
‘Cavers Lisbon’ – A vigorous ‘Lisbon’ selection originating in Upland, CA.
‘Cascade Eureka’ – Another, less-commonly planted, vigorous selection that originated in San Diego
County, CA.
‘Cook Eureka’ – A selection from Limoneira Del Mar Ranch, Ventura County, California.
‘Frost Nucellar Lisbon’ – Vigorous nucellar selection derived by Dr. H.B. Frost of the Citrus Research
Station, Riverside, CA
‘Limoneira 8A Lisbon’ – A vigorous selection originating from the Limoneira Ranch, Ventura County, CA.
The most popular lemon planted in Arizona today.
‘Prior Lisbon’ – A selection from California. Originated at the Rancho Sespe, near Fillmore, CA. Has a
reputation for lateness.
‘Rosenberger Lisbon’ – Although considered a ‘Lisbon’, possibly a hybrid of ‘Lisbon’ and ‘Villafranca’.
Vigorous and productive. Originated in Upland, CA.
‘Limonero Fino 49’ – The chief winter lemon of Spain. Reportedly vigorous, thorny and highly productive.
Early producer with uniform yield. Fruit is spherical to oval, with a smooth rind and a relatively short
nipple. Relative high acid and about five seeds per fruit.
‘Villafranca’ – Said to be of Sicilian origin, introduced into Florida in 1875. Formerly planted in
California, but of little importance there today. Fruit and tree characteristics similar to ‘Eureka’, but
produces mainly a winter crop.
‘Walker Lisbon’ – A vigorous selection from California, planted in 1997
1997 Lemon Cultivar Selection Trial. This trial, comprising 13 cultivar selections, was established in March 1997 in
Block 22 of the Yuma Mesa Agricultural Center, near Yuma, Arizona. The land was laser leveled and fumigated
prior to planting. Trees were planted on an 8-m x 8-m spacing. Fifteen trees of each selection were planted. This
trial includes ‘Allen’, ‘Cavers’, ‘Cascade’, ‘Cook’, ‘Limoneira 8A’, ‘Limonero Fino 49’, ‘Villafranca’ as well as the
following selections:
‘Arancino’ – A minor Italian cultivar, with rounded fruit, a short nipple and thick rind. Fruit is seedy.
‘Berna’ (‘Verna’) – The common summer lemon of Spain. Thornless tree produces medium to large fruit
with few seeds.
‘Corpaci’ – A minor Italian cultivar from Sicily. Vigorous, thorny trees are reportedly productive. Fruit
matures early and has few seeds.
‘Femminello Comune’ – Italian, everbearing cultivar.
‘Primofiori’ – Originated in Spain. Similar to the ‘Limonero Fino 49’ described above.
‘Santa Teresa’ (Femminello Santa Teresa) – Similar to ‘Femminello Comune’, but resistant to the Mal
Secco disease prevalent in Italy.
1998 Lemon Cultivar Selection Trial. This trial, comprising 7 cultivar selections, was established in late September
1998 in Block 14 of the Yuma Mesa Agricultural Center, near Yuma, Arizona. The land was laser leveled and
fumigated prior to planting. Trees were planted on an 8-m x 8-m spacing. Fifteen trees of each selection were
planted. This trial includes the ‘Limoneira 8A Lisbon’ and ‘Walker Lisbon’ described above as well as the following
additional cultivar selections:
Citrus Research Report (P-153) October 2007
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‘Dr. Strong Lisbon’ –Originated at the Glen Good ranch, Santa Paula, CA. Large fruit and the tree is
reportedly precocious.
‘Genoa’ – Similar to the ‘Villafranca’, imported from Italy to the U.S. in 1881.
‘Lapithotiki’ – Originated in Cyprus. Reportedly harvested from September until March. Fruit is tapered at
both ends.
‘Monroe Lisbon’ – Vigorous selection. Reportedly bears early, but fruit is small and coarse.
‘Taylor Eureka’ – A nucellar selection, originating in Australia. Reportedly produces late.
Yield data is collected during the fall and winter. Trees picked as noted as follows: For 2006-07, trees in the 1995
trial were picked on 10-12-06. Trees of ‘Allen Eureka, ‘Cavers Lisbon’ and ‘Walker Lisbon were not harvested as
the trees had been inadvertently irrigated when the pickers arrived. Trees in the 1997 trial were picked on 10-12-06,
and for the 1998 trial, trees were picked on 10-11-06. For each harvest date, a portion of the entire quantity of
harvested fruit from each tree was passed through an automated electronic eye sorter (Autoline, Inc., Reedley, CA),
which provides weight, color, exterior quality and size data for each fruit. Fruit packout data is reported on a
percentage basis. Fruit quality data, including juice %, peel thickness, ºbrix, %acid, and brix:acid ratio are reported
for trees in the 1997 and 1998 trial.
All data was analyzed using SPSS 11.0 for Windows (SPSS Inc., Chicago, Illinois).
Results and Discussion
1995 Lemon Selection Trial. Annual yields of the original ten selections in this trial, since its inception, are found in
Figure 1. For 2006-07, yields of all the selections decreased compared with the previous season. It is likely that this
was due to the large crop the previous year. ‘Cascade Eureka’ was superior for the second consecutive year.
Yields for the 2006-07 year are shown in Figure 2. There was no significant effect of the selections upon yield for
2006-07. In addition to ‘Cascade’, ‘Limoneira 8A’ performed well. ‘Prior Lisbon’ had the least yield for the year.
Packout for this trial is shown in Figure 3. Fruit size was generally large in 2006-07 since total yield was low.
‘Cascade Eureka’, ‘Cook Eureka’ and ‘Limonero Fino 49’ had the most fruit of size 75 and 95. followed by
‘Villafranca’. ‘Rosenberger Lisbon’ and ‘Prior Lisbon’ had the smallest fruit size for the second consecutive year.
There was a significant effect of selection upon fruit color, shape and exterior quality. ‘Prior’ and ‘Limonero Fino
49’ had the most highly colored fruit, while ‘Cascade’ and ‘Frost Nucellar’ had the greenest fruit. Significant
differences in fruit shape were found. ‘Villafranca’ had fruit that was rounder, while ‘Cascade Eureka’ fruit was the
most elongated. ‘Cascade’ also had the most fruit in the fancy category, with ‘Cook Eureka’ and ‘Villafranca’ with
only slightly less. These three selections also had the least fruit in the choice and juice category. ‘Limoneira 8A’,
‘Rosenberger’ and ‘Limonero Fino 49’ had the least fruit in the fancy category, while ‘Limoneira 8A and
‘Rosenberger’ had the most juice fruit.
1997 Lemon Selection Trial. Yields of this trial, since its inception, are found in Figure 4. Because of the large
number of selections in this trial, the graph has been split for ease of viewing. Selections that have had superior
yields since the beginning, include ‘Cascade Eureka’, ‘Cook’ Eureka, ‘Limoneira 8A Lisbon’, ‘Limonero Fino 49’,
‘Primofiori’ and ‘Villafranca’. All the yields fell precipitously this year, probably in response to the large crop last
year; only ‘Cascade Eureka’ stands out.
Yield for the 2006-07 season is shown in Figure 5. Although ‘Cascade Eureka’ had the greatest yield, ‘Cook
Eureka’, ‘Femminello’ and ‘Limoneira 8A’ were not statistically different. All the others performed particularly
poorly.
Citrus Research Report (P-153) October 2007
29
Packout for the 10-12-06 harvest is shown in Figure 6. There was no significant effect of selection upon fruit size
for 2006-07. There was no significant effect of selection upon juice %, juice pH, peel thickness, ºbrix, %acid, and
brix:acid ratio for 2006-07 (data not shown).
1998 Lemon Cultivar Selection Trial. 2001 to 2006 yields from this trial are found in Figure 7. Although the
‘Limoneira 8A’ was originally the best performer of this trial; 2006-07 is the third year that any other selection has
surpassed it in total yield since 2001-02, although there a great drop in overall yield for 2006-07, probably due to the
large crop for the previous year. . ‘Lapithiotiki’, ‘Genoa’, and ‘Dr. Strong’ Lisbon had yields that equaled or
surpassed the yield of ‘Limoneira 8A Lisbon’ (Figure 8). Meanwhile, ‘Genoa’, ‘Taylor Eureka’, Walker Lisbon’ and
‘Monroe Lisbon’ had yields less than ‘Limoneira 8A’, but there was no significant difference among any of the
selections. After consistently producing low yields up until 2004-05, we were surprised to see ‘Lapithiotiki’ vault
into the second-highest place in 2005-06 and have the third highest yield in 2006-07.
Fruit size for the 2006-07 harvest of this trial is shown in Figure 9. There was no significant effect of selection upon
fruit size for 2006-07. There was no significant effect of selection upon juice %, juice pH, peel thickness, ºbrix,
%acid, and brix:acid ratio for 2006-07 (data not shown).
Conclusions
Two new lemon cultivar selections appear promising for Arizona. One is ‘Limonero Fino 49’ lemon, because its
yields are similar to that of ‘Limoneira 8A’ and it has larger fruit size. ‘Cascade Eureka’ is also beginning to stand
out, having had equivalent or better yield than ‘Limoneira 8A’ for the last two years, along with better fruit size.
‘Femminello Comune’ and ‘Villafranca’ may also be suitable, but neither consistently equals or surpasses ‘Limoneira
8A Lisbon’ lemon in terms of overall yield and/or earliness as often as does ‘Limonero Fino 49’ or ‘Cascade’..
Furthermore, ‘Femminello’ performed poorly in 2005-06. ‘Santa Teresa’ had excellent yield in 2002-03, but
stumbled for the last three years, and is hobbled by its lateness. None of the other selections in the 1995 and 1997
trial have been consistently better than ‘Limoneira 8A Lisbon’.
In the 1998 trial, no selection has proved to be consistently better than ‘Limoneira 8A’, but ‘Walker’, ‘Monroe’ and
particularly ‘Dr. Strong’ may be contenders. ‘Lapithiotiki’ has large fruit, and high yields for the second year in a
row. ‘Eureka’ lemons have typically performed poorly in comparison to the ‘Lisbons’, and should not yet be
considered as a replacement for any of the high-yielding ‘Lisbon’ selections, with the exception of ‘Cascade’.
Citrus Research Report (P-153) October 2007
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Table 1. Fruit color, shape and exterior quality of eight lemon selections on C. volkameriana rootstock.
Selection
Fruit
colorz
Exterior Fruit Quality
(%)
Fruit
shapey
Fancy
Choice
Juice
Cascade Eureka
1.87 c
0.72 e
98.30 a
0.98 d
0.72 d
Cook Eureka
2.05 abc
0.75 cd
94.55 ab
5.00 d
0.55 d
Villafranca
1.93 bc
0.82 a
94.30 ab
4.44 d
1.26 d
Prior Lisbon
2.12 a
0.79 b
88.85 bc
7.78 cd
3.37 bc
Frost Nucellar Lisbon
1.89 c
0.78 bc
88.74 bc
8.16 bcd
3.10 bc
Limonero Fino 49
2.19 a
0.74 de
81.79 cd
14.46 abc
3.75 bc
Rosenberger Lisbon
2.22 a
0.76 bcd
79.98 cd
15.03 ab
4.99 ab
Limoneira 8A Lisbon
2.11 ab
0.77 bc
75.89 d
17.12 a
6.99 a
z
Value represents the red to green color ratio of the peel. A larger number indicates a more yellow or orange fruit,
while a smaller number indicates a greener fruit.
Y Shape indicates width to length ratio. A perfectly round fruit would have a value of 1.0.
x
Means separation in columns by Duncan’s Multiple Range Test, 5% level
Citrus Research Report (P-153) October 2007
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645
800
565
700
484
600
403
500
323
400
242
300
200
161
100
81
0
Harvest Year
7
20
06
-0
6
05
-2
00
5
20
20
04
-2
00
3
02
-2
00
2
20
20
01
-2
00
1
20
00
-2
00
0
19
99
-2
00
9
99
-1
19
98
-1
99
8
0
97
19
Approximate yield in field boxes per acre
(based on 30 x 30 ft. spacing)
Annual Yield (lbs. per tree)
900
Allen Eureka
Cascade Eureka
Cavers Lisbon
Cook Eureka
Frost Nucellar Lisbon
Limoneira 8A Lisbon
Limonero Fino 49
Prior Lisbon
Rosenberger Lisbon
Villafranca
Figure 1. 1997-2006 yield of ten lemon selections budded to C. volkameriana rootstock.
Citrus Research Report (P-153) October 2007
32
63
50
32
0
0
uc
bo
rL
io
Fr
os
tN
Pr
la
el
er
m
Li
is
bo
rL
is
no
Fi
o
k
oo
C
R
os
n
49
ka
re
Eu
sb
Li
er
rg
be
en
as
C
on
a
nc
f ra
lla
de
ca
Vi
re
Eu
sb
Li
8A
ra
ei
on
m
Li
Approximate yield in
field boxes per acre
(based on 24 x 24 ft. spacing)
100
n
95
on
150
ka
126
on
Yield
(lbs. per tree)
200
Selection
Figure 2. 2006-07 yield of eight lemon selections budded to C. volkameriana rootstock. There were no differences in yield among the selections for 2006-07.
Citrus Research Report (P-153) October 2007
33
Cultivar
Cascade Eureka
A
A
Cook Eureka
B
Limonero Fino 49
BC
Villafranca
BC
Frost Nucellar Lisbon
BC
Limoneira 8A Lisbon
BC
A
C
10
20
30
AB
50
60
75
95
115
140
165
200
235
285
B
A
A
40
B
AB
AB
AB
C
Rosenberger Lisbon C
B
AB
B
AB
B
AB
AB
C
B
AB
AB
C
0
BC
AB
C
Prior Lisbon
BC
A
B
C
C
A
70
80
90
100
Packout (%)
Letters indicate significant differences, within fruit sizes, between cultivars tested.
Figure 3. Packout of 8 lemon selections on C volkameriana rootstock for the 10-12-06 harvest. Bars of the same shade are significantly different if the lowercase
letters within them are different. Letters within bars of different shades cannot be compared.
Citrus Research Report (P-153) October 2007
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500
630
Allen Eureka
Arancino
Berna
Cacade Eureka
Cavers Lisbon
Cook Eureka
Corpaci
400
350
504
441
378
250
315
200
252
150
189
100
126
50
63
0
0
500
630
Femminello Comune
Limoneira 8A Lisbon
Limonero Fino 49
Primofiori
Sta. Teresa
Villafranca
450
400
350
567
504
441
150
189
100
126
50
63
0
0
00
20
06
-2
00
20
05
-2
00
20
04
-2
00
20
03
-2
00
20
02
-2
00
20
01
-2
00
-2
00
20
7
252
6
200
5
315
4
250
3
378
2
300
1
Annual Yield (lbs. per tree)
300
567
Approximate yield in
field boxes per acre
(based on 24 x 24 ft. spacing)
450
Figure 4. 2000-2006 yield of thirteen lemon selections budded to C. macrophylla rootstock.
Citrus Research Report (P-153) October 2007
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A
Yield
(lbs. per tree)
150
189
AB
100
126
ABC
ABC
BC
BC
BC
BC
BC
BC
BC
50
63
C
C
0
m
a
nc
f ra
Vi
lla
re
sa
ri
io
a
Te
of
nt
Pr
im
Sa
on
er
o
Fi
no
49
on
sb
Li
m
ra
Li
Li
on
ei
C
Fe
8A
m
m
or
in
el
lo
ci
pa
ka
C
re
oo
k
s
Li
Eu
sb
re
C
av
er
de
ca
C
as
on
ka
a
Eu
Be
rn
no
ci
an
Ar
le
n
Eu
re
ka
0
Al
Approximate yield in
field boxes per acre
(based on 24 x 24 ft. spacing)
252
200
October 12, 2006 Harvest
Selection
Figure 5. 2006-07 yield of thirteen lemon selections budded to C. macrophylla rootstock. Yields are significantly different if the letters above the bars are
different.
Citrus Research Report (P-153) October 2007
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Cultivar
Allen Eureka
Arancino
Berna
Cascade Eureka
Cavers Lisbon
75
95
115
140
165
200
235
285
Cook Eureka
Corpaci
Femminello
Limoneira 8A Lisbon
Limonero Fino 49
Primofiori
Santa Teresa
Villafranca
0
10
20
30
40
50
60
70
80
90
100
Packout (%)
Figure 6. 2006-07 packout of 13 lemon selections on C. macrophylla rootstock for the 10-12-06 harvest.
There was no effect of the selection on packout for the season.
Citrus Research Report (P-153) October 2007
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700
500
Taylor Eureka
Monroe Lisbon
Dr. Strong Lisbon
Genoa
Lapithiotiki
Walker Lisbon
Limoneira 8A Lisbon
756
630
400
504
300
378
200
252
100
126
0
Approximate yield in
field boxes per acre
(based on 24 x 24 ft. spacing)
Yield (lbs. per tree)
600
882
0
2001-2002
2002-2003
2003-2004
2004-2005
2005-2006
2006-2007
Harvest Year
Figure 7. 2001-2006 yield of seven lemon selections budded to C. macrophylla rootstock.
Citrus Research Report (P-153) October 2007
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120
October 11, 2006 Harvest
Yield (lbs. per tree)
100
80
60
40
20
i
t ik
La
pi
th
ur
rE
yl
o
Ta
(O
oa
G
en
io
ek
ne
Li
ld
Li
e
ro
on
M
a
)
on
sb
on
sb
Li
ng
ro
St
r.
D
Li
m
on
ei
W
ra
al
ke
8A
rL
Li
is
sb
bo
n
on
0
Selection
Figure 8. 2006-07 yield of seven lemon selections budded to C. macrophylla rootstock.
Citrus Research Report (P-153) October 2007
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Taylor Eureka
Monroe Lisbon
Selection
Dr. Strong Lisbon
Genoa Old Line
Lapithiotiki
75
95
115
140
165
200
235
285
Walker Lisbon
Limoneira 8A Lisbon
0
10
20
30
40
50
60
70
80
90
100
Packout (%)
Figure 9. Packout of seven lemon selections on C. macrophylla rootstock for the 10-11-06 harvest. Bars of the same shade are significantly different if the
lowercase letters within them are different. Bars of different shades cannot be compared.
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