HUME LIBRARY
Fr -,--- SEP 1 11972
rES 70-/OEverglades Station Mimeo Report EES 70-10 l ly, 1970
Lettuce Variety Performa eVd'AalVniv.0 of Florida
V. L. Guzman
Special conditions during the trials.-- The growing season was dry and
temperatures were conducive to good growth of the plants. A light freeze
occurred on December 15, which produced some burning of the margins of the
leaves, from which the plants recovered. Some of the varieties at near
harvest showed marginal necrosis of the leaf margins and pronounced
chlorosis of the older leaves. Although fertilizer was applied according to
Station recommendations, there were indications that some deficiency occurred.
This condition may have affected the performance of some or all of the varieties
under consideration.
Location: South Bay Growers farm, South Bay, Florida.
Soil type: Peaty muck, which was under cultivation with vegetable crops
for several years.
Design: Plots 2 x 30 feet, 2 x 25 at harvest, single rows arranged in a
4 x 4 balanced lattice.
Control of diseases, insects, and weeds: Was satisfactorily accomplished by
the farmer-cooperator.
Results
Tables 1 and 3 present summarized data for the replicated and observational
trials respectively. Ten responses were considered but only six were
statistically evaluated. These were weight of U.S. #1, number of U.S. #1,
mean head weight, number of heads left in the field after once-over
harvest, compactness and resistance to internal browning (I.B.). The analysis
of the data indicated that all responses except mean head weight showed highly
significant differences among the 16 varieties in the replicated experiment.
Table 1 presents the average adjusted value for each variety. The standard
error of the mean for each response is at the bottom of Table 1. Variety
differences were further investigated by the Duncan's Multiple Range Test.
Tinese results are presented in Table 2.
In Table 2, any two varieties not underscored by the same straight line
are concluded to be significantly different at 5% level. The value of the
responses in Table 2 are ranked from high (left) to low.
When considering all the horticultural characteristics plus yields,
Fulton and Minetto were the most outstanding varieties followed by G.L. 200
and Mesa 659M.T. Observations made during the season in the farmer's field
indicated that Fulton is more susceptible to ribbness than Minetto, and that
Minetto at times tends to produce heads slightly smaller than Fulton.
oMinetto appears tb stand better light freezes than Fulton, especially near
harvest. Although these two varieties seem to be better adapted to our
conditions, there is an urgent need to produce or evaluate more varieties
with the hope of finding the most adaptable to our ever-changing climatic
conditions. In addition, nutritional Work should be concurrently carried
out to determine the most pressing nutritional needs of the new varieties.
In the observational trials (Table 3) Fulton x 313 (released by the
University of Wisconsin as Marquette) produced the highest yields of heads
of good quality. Head size of this variety may be:slightly smaller than
the requiredsize to make a 24 head carton. the Fuiton lines tested in the
observational trial were not as good as the one in the replicated trial.
Oswego was inferior to Fulton and Minetto in regard to head quality. Oswego
tends to become over-mature in less time than Minetto and Fulton. Other
varieties that may be promising are: G.L.659, Great Lakes 66 and Great Lakes
65.
Key to Tables
Seed sources: ASG = Asgro Seed Company, Milford, Conn.; J. H. = Joseph
Harris Seed Co., Rochester, N. Y.; SRS = Seed Research Specialities,
Gilroy, California; Key = Keystone Seeds, Hollister, California; FM-=
Ferry Morse Seed Co., Salinas, California; U. Wis. = Dr. Sequiera, Madison,
Wisconsin.
Rating for compactness,resistance to, internal browning, appearance, and
color were from 1 to 5. Five indicates the most desirable degree of a
given observation and one the least desirable. Example: Five for
appearance would indicate the most eye-appealing lettuce head, or the most
resistant to internal browning, or the darker green color.
Table 1. Adjusted Variety Means
Resistance and Internal- Browning
for U.S. No. 1 grade, Head Weight, Heads
on Lettuce Varieties Seeded November 27,
left in the Field, Compactness and
1968 and Harvested February 17-24, 1969.
Varieties
iulton M.T.
Oswego M.T.
Minetto M.T.
Mesa 659 M.T.
Empire 514
G.L. R200
B. L. 6238
Calmar
Vanguard
Golden State
Merit
Green Bay
Greenland
Forty Niner
Caravan
Shipper 212
ASG
J.H.
J.H.
J.H.
J.H.
SRS
SRS
KEY
KEY
FM
FM
FM
FM
FM
FM
ASG
-4
4J
0
4J
r
83
83
83
85
90
86
89
90
91
90
89
90
91
90
90
90
26.01
15.44
19.65
17.69
19.16
24.50
27.65
26.07
15.20
21.30
33.14
21.04
22.77
15.88
27.48
25.74
I .........1 __ __Li I I
L I I
1/ 5 most desirable to 1 Least desirable
1 I
16.67
11.54
16.04
14.54
15.60
17.79
18.04
16.36
12.04
14.42
20.98
14.10
15.23
10.04
17.73
16.56
653
399
581
545
581
690
653
581
399
545
726
545
545
363
653
617
1.539
1.301
1.201
1.227
1.251
1.414
1.589
1.539
1.301
1.489
1.589
1.489
1.458
1.620
1.520
1.497
7.86
9.80
8.61
6.30
6.17
4.49
7.93
5.74
11:866
7.80
3.36
6.55
5.67
12.24
6.17
2.25
3.47
2.97
4.41
3.16
2.53
3.41
2.60
3.22
2.10
2.60
3.16
2.91
2.10
1.97
3.03
2.92
4.39
3.96
5.02
4.70
2.77
4.89
3.27
3.14
3.64
2.77
2.83
3.33
3.14
2.58
3.58
3.27
i I I I
-
-
. ... -- i
'
'
*
Table 2. Results of Duncan's Test Based on Adjusted Variety Means
Weight, U.S. #1
Number, U.S. #1
11 7 15 8 1 16 6 13 10 12 3 5 4 14 2 9
11 7 6 15 1 16 8 3 5 13 4 10 12 9 2 14
Number Left in Field 14 9 2 3 7 1 10 12 4 5 15 8 13 6 11 16
Compactness
Resistance to I.B.
3 1 6 8 4 11 15 2 16 12 7 10 5 9 13 14
3 6 4 1 2 9 15 12 7 16 8 13 11 5 10 14
Table 3. Observational Lettuce Variety Trials, Seeded November 27, 1968,Harvested
: Varieties
Oswego MI 999%
G.L. 659 Mesa
Fulton MI 999%
G.L. 659 MI 999%
Oswego
Fulton
Great Lakes 659
Pennlakes Mt 533
iMt
Great Lakes 65!
Great Lakes 66
Mt
Great Lakes 65
Mt
Great Lakes 62:
Mt
Great
Lakes 659
Mt
Fulton Mt
Mesa 659 Mt
Vanguard Mt
Empire Mt
Oswego Mt
Minetto Mt 528
Fulton x 311
I I t k I I
4 "1 1
S.R.S.
S.R.S.
S.R.S.
S.R.S.
KEY
KEY
KEY
J.H.
J.H.
F.M.
F.M.
F.M.
IF.M. 86
!F.M. 83
F.M. 85
F.M. 90
F.M. 91
F.M. 83
J.H. 83
Univ. o
Wisc. 83
p Ir _________ ________ -
18.3
28.2
27.4
19.1
16.9
24.7
23.3
29.9
22.0
27.8
18.2
25.5
25.9
28.3
18.0
21.0
20.8
19.4
25.7
34.2
F-4
td EZ
( 0
5
5
4
5
5
5
5
5
5
4
5
4
5
5
5
2
2
5
5
5
1.2
1.5
1.7
1.2
1.1
1.4
1.5
1.5
1.4
1.6
1.3
1.4
1.4
1.5
1.4
1.5
1.2
1.2
1.5
1.6
545
690
617
581
581
690
581
726
617
653
508
690
690
690
508
508
617
617
617
799
3
4
4
3
3
3
4
3
3
4
4
3
3
3
4
3
3
4
3
4
I
- ,, ...
I
February 17 to 24, 1969 (Experiment 579
9
38
Table 3. Continued
ot
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In
4-
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0
U
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5-4
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9.4
40 Fulton x 312 Univ. 83 25.6 17 1.6 2 617 4 5 3 3
of
Wisc.
a. 5 lost desirable to T'- least desirable
41 Fltonx 31 of ~ 83 29.622d.4s7ra5bl3e
EES 70-10
300 copies
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