GERALDSON: TOMATO FERTILIZATION
regarded as being primarily controlled by the
available supply of potassium and comparatively
little affected by the available calcium supply in
the nutrient medium. In this experiment the
lower percentage of calcium in the okra plant
tissue is more closely associated with the rate
of potassium applied than the percent potassium %
in the plant. This indicates that the higher po
tassium level decreased calcium absorption and
the calcium level had very little effect on po
tassium absorption.
Summary
The results from this experiment show that
relatively high initial rates of nitrogen in com
bination with the higher rates of phosphorus
153
reduced early yields of okra. The higher rates
of potassium had no beneficial effect on yields.
The treatment combination that resulted in the
highest early yields did not supply enough nitro
gen to maintain a relatively high yield over a
long harvest period. It appears it would be
beneficial to side-dress okra with nitrogen even
if leaching is not a problem.
LITERATURE CITED
1.
Eguchi, T., T. Matsumura and M. Ashizawa.
The
effect of nutrition on flower formation in vegetable crops.
Proc. Amer. Soc. Hort. Sci. 72:343-352. 1958.
2. Hester, J. B. and F. A. Sheldon. Campbell Soup Co.,
Riverton, N. J. Research Monograph 3:1-99. 1949.
3. Peech, Michael and Richard Bradfield. The effect of
lime and magnesia on soil potassium and on the absorption
of potassium by plants. Soil Sci. 55:37-48. 1943.
4. Ware, L. M.
Influence of the major fertilizer ele
ments on the earliness and yield of snap beans. Proc. Amer.
Soc. Hort. Sci. 35:699-703. 1937.
QUANTITY AND BALANCE OF NUTRIENTS REQUIRED FOR
BEST YIELDS AND QUALITY OF TOMATOES
C. M. GERALDSON
reason and economically feasible.
Gulf Coast Experiment Station
Bradenton
Yields
of
over
3,000
bushels
per
acre
of
greenhouse tomatoes have been produced in ex
perimental plantings in Michigan and commer
cial greenhouses in Europe
(8).
At the present
time 20 pounds of fruit per pruned tomato plant
(equivalent to 3,000 bu. from 9,000 plants/A.) is
considered a very high yield, whereas 10 pounds
per plant (although infrequently attained)
is a
good goal for most hydroponic or vine-ripe to
mato growers in Florida.
bushels
per
acre
of
A yield of 300 to 500
mature-green
tomatoes
is
considered average to good. Yields of 500 bushels
per acre from a staked crop of 6000 plants per
acre or a wide-row crop of 1,200 plants per acre
means a per plant production of 5 and 25 pounds
respectively.
Whether the tomatoes are produced hydroponically, in the greenhouse, or in the field, the
vine-ripe characteristic
quality which brings a
premium on the market and the associated high
yields generally warrant the high cost of pro
duction per acre.
A much lower
production cost is generally associated with the
mature-green tomato but unless yields are rela
tively high the unit cost of production may be
Furthermore any practice or
change which tends to maintain or improve
quality and increase yields is generally within
Florida Agricultural Experiment Stations Journal Series
No. 1727.
come excessive.
Because nutrition is basic to the production
of good quality and high yields, it is of major
importance in maintaining or improving quality
while increasing yields as well as for increased
yield itself. The discussion that follows is de
signed toward a better understanding of the
total nutritional picture as well as suggested pro
cedures for improvement. At present, the goal
for vine-ripe tomatoes should be 2,000 bushels
per acre and 1,000 bushels per acre for maturegreen
tomatoes.
The quantity of nutrients, the sources, place
ment and resultant effect on nutrient balance
and the associated effect on plant response will be
discussed.
Quantity op Nutrients Required
Plant analysis can be used as a basis of in
dication of nutrient requirement as illustrated
in Table 1. Percentages were derived as averages
of figures presented in literature cited (4, 5, 7)
as well as from numerous samples from all parts
of Florida analyzed at the Gulf Coast Experi
ment Station (insufficient data available for
zinc, copper, molybdenum and sulphur).
FLORIDA STATE HORTICULTURAL SOCIETY, 1963
154
Table 1.
Percent nutrients in tomato tissue and the
corresponding quantity of these nutrients
required per production unit.
Nutrients
Dry tissue
to
produce 1000
1000# fruit wt.
bu./A.
(60#/bu.)
Nutrient
Plant
Fruit
Plant
Fruit
Calcium (Ca)
Potassium (K)
Magnesium (Mg)
Nitrogen (N)
Phosphorous (P)
Iron (Fe)
Manganese (Mn)
Boron (B)
2.0%
0.2%
0.15 lbs.
159.0 lbs
3.5
4.0.
3.0
0.6
0.2
442.5*
54.0
2.5
0.4
3.0
2.5 lbs.
4.375
0.75
3.125
0.6
0.50
0.005
0.002
0.002
0.1875
0.015
0.01
0.005
0.0125
0.00675
0.15
2.25
0.45
0.00375
0.0015
0.0015
322*5*
57.0*
1.35
0.84
0*465
*From these figures, over 3 tons of a 5-2-8 analysis would be requir
ed to produce 1000 bu./A.
Methods
The plant nutrient requirement (Table 1) is
used as a basis in these experiments for nutrients
supplied, taking into consideration that the soil
base exchange organic matter and cover crops
can supply portions of both the major and minor
nutrients.
In order to further evaluate fertilizer source,
level, placement and movement of nutrients in
regard to effect on nutrient concentration and
balances in the soil solution and the resultant
plant response, the following described field
experiments were conducted in the spring of
1963. In the first experiment (table 2), three
variations in fertilizer source material in com
bination with three levels were evaluated with
respect to yields and quality of a staked crop
of Manapal tomatoes. In a second experiment
(table 5) three fertilizer placements in combi
nation with 3 nitrogen levels were similarly com
pared using a ground crop (not pruned) of STEP
410 tomatoes. In order to eliminate the down
ward movement of nutrients (leaching due to
rain) all plots were covered with black plastic
mulch (1.5 mil) applying all the fertilizer before
covering. A 4-foot width was used on the staked
crop and a 6-foot width on the ground crop.
Beds were flat topped or with a very slight
slope from the center. In the first experiment
approximately 90 percent of the fertilizer was
placed on the bed surface in 2 bands 12 to 15
inches from the plant; the remaining 10 percent
was broadcast between the bands. Fertilizer in
the second experiment was applied as listed in
Table 2 and further described in the Results
and Discussion section. Phosphorus (46%) was
broadcast over top the bed at a rate of 400 lbs./A.
Two units of magnesium and 15 pounds of Frit
(FN 502) per ton were included in the high
analysis fertilizer. The pH of the Leon type
soil averaged 6.5 to 7.0. Seep irrigation was
used to maintain a relatively high water table.
Drainage was good.
All fruits were harvested in the pink stage.
Yields of marketable fruit (number and weight)
and culls were recorded. Soil solutions salts (2),
calcium, potassium, nitrate and ammonia nitro
gen, phosphorus and pH were determined for 3
depth fractions in the soil bed. Percentages of
Ca, K, N
and
P were
determined in
selected
plant tissue samples.
In cooperation with the County Agricultural
Agent, soil and plant tissue samples were taken
from a number of commercial tomato fields dur
ing the spring crop season and results are re
corded in Tables 6 and 7.
Results and Discussion
Regardless of fertilizer source or level, yields
obtained (table 2) averaged over 1000 bu./A.
This was the first crop following a heavy pangolagrass pasture and a relatively large amount
of nutrients from this source was available. This
GERALDSON: TOMATO FERTILIZATION
Table 2,
155
The effect of three fertilizer source variables
in combination with three levels on yields
and quality of staked tomatoes.
Average
Firm
Black
Source
Rate/A.
Yield/A.
size
(1) 18-0-25
(Urea +
potassium nitrate)
(2) 18-0-25
(Urea +
potassium sulfate)
(3) Commercial
ness*
1000 lbs.
2000
1198 bu.
.406 lbs.
.409
7.25
6.00
shoulder*
6.25
5.25
4000
1430
6.00
1260
7.25
6.75
2000
4000
1513
1001
.433
.425
.417
4.50
1000
3000
1147
.419
6000
1109
.386
7.75
3.25
6.75
8.00
7.75
1.75
7.75
6.50
12000
1060
.391
5.75
6.00
6-8-8
25% organic
1369
.422
^Results are an average of 4 replications, with best ratings on the high
end of a 10 to 1 range.
Statistical significance:
Yield and size
- no significance.
Firmness and Black shoulder LSD - 2.25
may be one reason why yields were relatively
high at a calculated inadequate nutrient level.
Also plant tissue analyses (table 3) were lower
than those averages
given in Table
1, and in
dicate either less required nutrients (percentage
wise)
and/or
inadequate
latter part of the
poorer
vine
season
growth
a
Toward
lighter
color
associated
with
the
and
the
lowest level. Further evidence of nutrient de
pletion at lowest fertilizer level was the exten
sive development of roots near or on the soil
Table 3.
was
supply.
surface. Both the above mentioned visible evi
dence and the low level-low plant content data
can be correlated with the low-level-low soil
solution nutrients data (table 4).
In contrast the only other measurable effect
was associated with the highest fertility levels:
an excess of salts was indicated by plant ap
pearance (dark green and sometimes droopy and
generally slower growing) when potassium sul
fate and urea was the source material and then
only at the drier end of the field and at the
The effect of fertility level (from the Table 2
experiment) on the analysis of dry plant tissue (6/5/63)*.
Fert.
Calcium
Potassium
Nitrogen
level
Tissue
Low
Young leaf
0.48%
1.57%
2.02%
Old leaf
1.93
2.56
1>67
Fruit
0.15
1.46
2.96
0.16
4.28
1.86
2.47
3.21
4.30
3.12
Old leaf
1.48
3.22
Fruit
0.16
2.48
2.00
3.98
Medium
Young leaf
Old leaf
Fruit
High
Young leaf
Phosphorous
0.14%
0.12
0.43
0.25
2.48
0.20
2.23
0.38
3.37
2.84
0.20
0.50
2.60
0.46
*Average of samples from all 3 source materials*
FLORIDA STATE HORTICULTURAL SOCIETY, 1963
156
Table 4.
The effect of fertility level (from the table 2
experiment) on the non-leached nutrient in the
soil solution (ppm) at three depths (6/5/63)*
Fert.
Soil
level
fraction
Salt
4400
0-2"
2-4
Low
Medium
4-8
0-2
High
2-4
4-8
0-2
Ca
1191
227
171
1809
1003
646
12010
3348
704
1140
30730
6783
1349
2-4
4-8
K
265
33
NH<i
35
32
14
17
8
483
38
12
0
2449
159
10
257
3049 12049
1300
868
56
332
NCh
60
1967
273
16
621
64
29
1318
P
pH
74
3
4
175
6.4
7.0
6.9
6.4
6.5
6.7
6.5
12
8
277
311
48
20
6.5
5
6.8
* Samples taken 12 to 15" from the plant (area where 90%
of the fertilizer was applied)o Averages of all 3
source materials.
highest level (4000# 18-0-25/A.). This effect
was reflected by the relatively lower yields and
especially poorer quality in terms of firmness and
black shoulder (table 2). Ripe fruit which had
been harvested pink were evaluated for fruit
firmness
and
black
shoulder
(darkening
and
softening of the fruit shoulder) by Dr. J. M.
Walter. Soluble salt reading at the highest fer
broadcast on the bed surface between 1900 lbs.
of 18-0-25 in 2 bands 6" from the plant; similarly
600 lbs. was placed between 1800 lbs. in the 12"
bands and 900 between 1700 lbs. of the 18-0-25
in bands 18" from the plants. When the ferti
lizer was placed 6" from the plant, stands of set
plants were decreased; but once the plants were
established further
detrimental
longer observed.
ium sulfate + urea—41,600 ppm; potassium ni
which was available to the plant for 3 different
trate
time intervals from time of setting until they
reached the banded fertilizer, resulted in equiva
+
urea—20,800;
and
29,800
with
the
6-8-8.
In
the
second
experiment,
with
fertilizer
placement and nitrogen level as variables, (table
5) yields again averaged over 1000 bu./A. Three
hundred pounds of the 2-8-8, 4-8-8 or 6-8-8 was
Table 5.
Nitrogen
effects were no
tility level, 0-2" depth, were as follows: potass
at 2, 4
or 6 units,
lent yields.
Results from selected field samples are in
cluded in Table 6 to illustrate certain nutrient
concentration and balance factors which might
A summary of the effects of three fertilizer placements
in combination with three nitrogen levels on the
yields and quality of ground tomatoes.
18-0-25
Potassium nitrate
6"
12"
18"
from plant
urea
Average
Average
Between
Yield
Size
bands
Yield
Size
1096 bu./A.
.373 lbs.
2-8-8
1148 bu./A.
.374 lbs.
1175
.380
4-8-8
1167
.382
1182
.389
6-8-8
1138
.385
Statistical significance: None
GERALDSON: TOMATO FERTILIZATION
Table 6.
157
Balance of nutrients in soil and hydroponic solu
tions and associated yields.
ppm nutrients in the cultural solution
Field
Field Date
Manatee
1 3/1/63
2620
1 4/12
5600
2600
1 5/1
2* 3/19
2860
2* 4/22
5660
2* 5/14
6500
2*a5/14 0-2" 15900
1840
2**5/14 2-4
1550
2*a5/14 4-8
3 5/1
2900
Ruskin
4* 3/5
5 3/5
Homestead
6
Wisconsin
Hydroponic 7
Salt
.
N03
115
635
786
262
414
926
1146
204
424
310
38
280
88
570
447
1878
1662
1372
208
214
407
65
35
248
60
84
84
21
16
34
684
1303
536
200
3480
4300
1740
1/10/63
K
220
321
2174
8/1/62
Ca
341
NHf,
P
90
68
230
156
18
60
58
43
24
15
50
17
pH
600 bu./A.
6.3
6.9
30#/plant
1500 bu./A.
10
6.5
6.6
6.6
6.6
7.4
42
6.5
16
30
10
Yield
6.4
6.0
or
or
10#/plant
Av.
Size
small
to
medium
medium
to
large
600 bu./A.
small
or 6#/plant
mecTium
424
43
1
9
7.5
good
116
230
1
8
poor
584
390
455
40
18
7.8
7.1
210
15
33
5.5
10#/plant
----
average
medium
*Fruit from these fields was harvested pink (vine-ripe production).
All other fields
were harvested mature green.
On 5/14 (2*a) a duplicate sampling was taken at 3
fractional depths as listed in the table.
be correlated with plant response. Field 1 is
typical of a number of fields sampled (maturegreen harvest) during the spring crop season
in the Manatee-Ruskin area. Nutrient levels were
kept relatively low by February rains, tending
to build up in March and decrease due to plant
utilization in April and May. This was especially
true with nitrogen in most fields. Most growers
during the later part of the season periodically
applied top dressers of nitrogen and potash which
tended to sustain nutrition even though levels
were low.
Yields were relatively high
(400 to
600 bu./A.) but most growers were not satisfied
with fruit size. The No. 3 field with a 600 bu./A.
yield from a staked and pruned crop of about
6000 plants per acre can be compared to the No.
1 field where 1200 plants (wide-row culture)
produced 600 bu. Approximately equivalent nu
trients were applied to each field.
The No. 2 field
(vine-ripe harvest)
during
Table 7.
Percent calcium, potassium, nitrogen and
phosphorous in young leaf tissue from the same fields
listed in Table 6.
Field
Date
Ca
K
N
1
4/3
5/14
6/11
4/3
3/5
3/5
1/20
0.69
4.09
1.14
1.68
0.56
1.30
1.20
0.51
2.98
2.75
4.23
3.79
4.64
3.39
2.88
4.26
3.65
4.87
4.06
2*
2*
3
4*
5
7
2.92
3.88
0.44
0.30
0.14
0.57
0.30
0.37
0.30
a maximum requirement period received as much
as 40 to 50 lbs. each of N and K2O per acre
per week to maintain the indicated level. As
indicated in Table 6, yields were high and fruit
size and quality were generally good. The frac
tioned soil sample data (Table 6) indicates dis
tribution of nutrients during dry weather to be
much the same as under plastic (Table 2) and as
with plastic for proper utilization, a high water
table was necessary. Fertility levels as well as
profile distribution can be radically altered by
rains (2). In order to encourage root develop
ment high in the bed, fertilizer should be placed
high with accompanying high water tables; this
practice also encourages relatively less loss of
roots and fertilizer when excessive rainfall oc
curs. Although the composite soil sample (Table
6 field 2) indicates relatively high salt levels,
the fractioned soil indicates relatively low levels
in the effective root zone. It should be pointed
out that primary roots are relatively salt sensi
tive, whereas secondary roots are relatively salt
tolerant and often proliferate profusely in the
vicinity of the fertilizer band (1). Such pro
liferation is desirable because the nutrient-ab
sorbing capacity is proportional to the root sur
face area.
The potassium level in the high yielding
Homestead field (No. 4) was relatively high
(19.5%) whereas a relatively low potassium level
FLORIDA STATE HORTICULTURAL SOCIETY, 1963
158
(3.3%)
was
found
Homestead field.
in the
low yielding No.
5
Both fields contained relatively
high calcium levels (31.5 and 37.4% respectively).
The Wisconsin soil (No. 6), a heavy clay soil
centration in the soil solution
(indicator of nu
trient level) of 2000 to 3000 ppm in the effective
root zone is recommended.
As balance factors,
calcium should be maintained at about 15%
the total salt;
parison because the sole source of nutrients was
nitrogen at 3 to 10%.
manure.
or plant utilization can be alleviated by additions
The hydroponic solution
(No. 7)
is also in
teresting as a comparison in that concentrations
and balances can be directly compared to
soil
potassium at 10%;
of
which was non-irrigated, is interesting as a com
of certain nutrients at the proper time. Accumu
trolled. A relatively high water table is essential
for best results
on plant growth can be studied.
mulch.
The analysis of leaf tissue (table 7) from the
centages of most nutrients tested.
stage
of growth
and
season
1000 bu./A. for mature-green tomatoes.
It should be
can
affect the
interpretation of results obtained from the an
alysis of leaf tissue (5).
LITERATURE CITED
Hort.
3.
When the plant and fruit average composition
are used as an indicator, approximately 320 lbs.
of N, 60 lbs. of P and 440 lbs. of K (as an ex
production
Balance
of
solution
is
of
nutrients)
1000
the
bu.
of
are
required for
tomatoes
required nutrients
essential
for
yields and best quality.
1.
Duncan, W. G. and A. J. Ohlrogge. 1959. Principals
of nutrient uptake from fertilizer bands. II Root development
in the band. Agron. Jour. 50:605-608.
2.
Geraldson, C. M. 1957. Soil soluble salts—Determina
tion of and association with plant growth.
Summary
ample of 3 major
either with or without plastic
At present the production goal for vine-
ripe tomatoes should approach 2000 bu./A. and
pointed out that time of sampling with respect
to
Deviation due to leaching
lations of salts or specific ions can also be con
solutions, and the effect of controlled variations
above mentioned fields indicated satisfactory per
and nitrate
per
in
production
acre.
the
soil
of highest
A total soluble salt con
Soc. 70:121-126.
Geraldson, C. M.
1962.
Growing
Proc. Fla. State
tomatoes
and cu
cumbers with high analysis fertilizer and plastic mulch.
Proc. Fla. State Hort. Soc. 75:253-260.
4.
Goodall, D. W. and F. G. Gregory. 1947.
Chemical
composition of plants as an index of their nutritional status.
Tech. Comm. No. 17. Imperial Bureau of Hort. and Plan
tation Crops, Aberystwyth, Wales.
5.
Howard, D. F. et al.
1962.
Nutrient composition.
Calif. Agri. Expt. Sta. Bull. 788.
6.
Orth, P. G. and R. W. Harkness. 1962. Intra seasonal
variations in nutrient content of young tomato leaves. Proc.
Fla. State Hort. Soc. 75:260-268.
7.
Sims, G. T. and G. M. Volk. 1947. Composition of
Florida-grown vegetables. Fla. Agr. Expt. Sta. Bull. 438
8. Wittwer, S. H. 1960.
Practices for increasing the
yields of greenhouse tomatoes. Mich. State Agri. Expt. Sta.
Circ. Bull. 228.
SOME EFFECTS OF POOR POLLINATION IN TOMATO
James M. Walter
is
Gulf Coast Experiment Station
Bradenton
Introduction
The favorable-market period for spring-crop
grown in the Bradenton-Ruskin area
tomatoes
ended on May 9 in 1959, 1961, and again 1963.
Coupled with the failure of their crops to
set
only part of the problem.
One-sided and
dwarfed fruits that are not acceptable to the
shipping market are other aspects of it that are
often deceiving and costly to growers. "Puff"
and "pockets" are expressions used by many to
cover the one-sided or poorly filled, cull fruits
commonly found to have no seed in one or more
locules. Slow development and dwarfing of fruits
are the effects of poor pollination that results
in very few seed per locule. Seldom does a
grower in the Bradenton-Ruskin area find it
fruit during March, this has meant that several
profitable to harvest tomatoes le'ss than 5 oz. in
growers
have
weight,
market.
This problem of large acreages of to
missed
or
nearly
missed
their
not at
approximately
all unusual
in
the
"6 x 6"
the
area
to
size.
It
is
find, when
matoes going week after week making numerous
harvest has been completed on a staked acreage
flowers but setting few if any fruits has plagued
the growers of the area for a decade, with many
still has 20 dwarfed fruit, none weighing more
of the variety Homestead, that the average plant
acreages planted in December delaying fruit-set
than 3 oz., or being more than 2" in diameter, or
until early May.
Complete failure to set fruit by a given date
having more than 10 seed.
The writer has been
recording observations