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Copyright 2005, Board of Trustees, University
Fort Pierce ARC Research Report RL-1979-5
H ME LIBRARY
Survival and yield in late fall of tomato lines ith partial
resistance to bacterial wilt UX 12 1979
R. M. Sonoda, J. J. Augustine, and R. B. V linl/
1FA.S.. Univ. of Florida
Several CAB 54 tomato accessions (102, 106, 135-1, 135-2, 14
and 123-1) transplanted on October 17, 1978 into a field naturally
infested with Pseudomonas solanacearum E. F. Smith, had significant-
ly more survivors (36.7 to 56.4%) than commercial variety Walter
(5%). Yields per plot were significantly higher for accessions 102
and 123-1 (7.5 and 6.4 kg, respectively) than for Walter (1.7 kg).
Size of the first ripe fruit of Walter was slightly larger than
that of 102 or 123-1. The growing season in 1978-79 was warmer
than a six-year average, 1972-1978., probably contributing to the
greater than expected losses in the partially resistant accessions.
Previous work (1) indicated that tomato accessions with inter-
mediate levels of resistance to bacterial wilt incited by Pseudomonas
solanacearum E. F. Smith can be safely grown in fields highly in-
fested with the pathogen in late fall in south Florida. Horticul-
turally suited lines with partial resistance to bacterial wilt are
not yet available to growers. The object of the current experiment
was to determine survivability and yield of CAB 54 tomato accessions
with partial resistance to bacterial wilt.
Materials and Methods
Seeds of tomato accessions (Table 1), selected from a cross
(CAB 54) made by the late J. M. Walter (University of Florida) and
found to have some resistance to P. solanacearum in field tests at
the Agricultural Research Center, Fort Pierce (ARC-FP) (2), were
sown in Jiffy Mix Plus in plastic multipots. Seedlings were grown
in the greenhouse for 2 weeks, then moved to outside benches to
harden for 2 weeks before transplanting to a field heavily infested
with P. solanacearum (2) at the ARC-FP on October 17, 1978. In
addition to the CAB 54 accessions, the Florida commercial variety
'Walter' was planted as susceptible control and Hawaii 7997 as re-
sistant control. Four replications of 10 plants each were planted
except for accession 117-4 with eight plants per replicate and
accessions 40, 117-5 and 118-1 with six plants per replicate. The
plants were transplanted to double rows on beds with two feet bet-
ween plants down-row. The design of the experiment was a randomized
1/ Associate Professor, University of Florida, Institute of Food and
Agricultural Sciences, Agricultural Research Center, Fort Pierce;
Assistant Professor, UF, IFAS, Agricultural Research and Education
Center, Bradenton; and Associate Professor, UF, IFAS, Agricultural
Research and Education Center, Homestead.
Ripe fruit were harvested from the plots on January 11, 1979.
All fruit heavier than 100 g were harvested on January 19. The
number of plants severely affected by bacterial wilt was recorded
weekly beginning 4 weeks after transplanting.
Analysis of variance was carried out on all data. Data ob-
tained as percentages were transformed to arc-sin before analysis
of variance. Mean separation was made with Duncan's Multiple
Maximum and minimum daily temperature data for 1972 to 1977
were obtained from maximum and minimum thermometers located in a
weather shelter about 100 meters from the plot area. Temperatures
for 1978-79 were obtained from thermometers in a weather station
about 500 meters from the plots. Mean weekly temperatures were
calculated from the maximum and minimum temperatures.
Results and Discussion
Plants categorized as survivors were healthy or only slightly
affected by the disease. Hawaii 7997 had the largest number of
plants surviving at the end of the experiment (Table 1). No yield
data were taken for this accession as fruit were small as reported
Of the CAB 54 accessions, 102 had the largest percent of plants
surviving and the highest yield per plot (Table 1). Six other acces-
sions had significantly more survivors than the susceptible 'Walter'.
Only accession 102 and 123-1, however, outyielded 'Walter' on a per
plot basis. Average fruit weights of the first ripe fruits for 102,
123-1, 135-1, and 'Walter' were 150, 145, 141, and 159 g, respec-
tively. Accessions 14 and 106 had smaller fruit weighing 132, and
127 g, respectively. These results indicate that the CAB 54 lines
may be slightly smaller-fruited than 'Walter'. Due to the death
of most of the 'Walter' plants and the possible effect of the disease
on fruit size, further yield and quality comparisons of 102, 123-1,
135-1, and 135-2 with Florida commercial varieties in uninfested
fields are warranted. Fruit shape of 102 and 123-1 was similar to
'Walter'. In a preceding test (1), fruit of these accessions
appeared to be slightly more irregular than 'Walter'.
Although 52.3% of line 135-1 died during the experiment re-
ported here, in a similar test in 1977-78 (1), no plants of 135-1
were killed when transplanted on October 12, 1977. The generally
warmer mean weekly temperatures during the late fall-winter of
1978-79 (Fig. 1) as compared to 1977-78 may account for the greater
incidence of bacterial wilt. Less disease would be expected in the
fall if temperatures remained near 1972-78 averages.
The field in which the experiment was carried out was, as
stated above, heavily infested with the pathogen by repeated
plantings of susceptible tomato varieties for several years. Most
grower fields would not be as heavily infested. Studies are needed
to determine what the combined effect of temperature, level of ino-
culum and level of bacterial wilt resistance will have on disease
development and subsequent yield loss.
1. Sonoda, R. M. 1978.. Effect of differences
tomato to Pseudomonas solanacearum and
on incidence of bacterial wilt. Plant
in tolerance of
time of planting
2. Sonoda, R. M. 1977. Behavior of tomato lines, selected for
resistance to southern bacterial wilt, in a field infested
with the pathogen. Fort Pierce ARC Research Report
Table I. Survival and yield of CAB 54 tomato accessions transplanted
October 17, 1978 into a field at the Agricultural Research
Center, Fort Pierce naturally infested with Pseudomonas
solanacearum E. F. Smith.
1/ As of January 19, 1979.
2/ Harvested on January 11 and 19, 1979.
3/ Means in the same column followed by the same letter are not
different at the 5% level (Duncan's Multiple Range Test).
o Avg. 1972-78