Download effect of urea nitrogen on nutritional leaf roll of tomatoes

VOLK:
TOMATO LEAF ROLL
It is evident that in the last twenty years
we have doubled our yields in these crops. Seed
has played its part in this condition as much
as has any of the other contributing factors.
Now let us see what has happened in the
last ten years as far as some of our vegetable
crops are concerned: (2)
Total Acreage
Crop
Year
1948
Snap Beans
(Winter)
1948
1957
Celery (Winter)
Celery(Winter)
6,300
6.3CO
1948
Celery
5,300
4,000
1957
1957
(Spring)
Yield per A.
87 Bu.
19,000
16,900
123 Bu.
540 Crates
653 CrateB
430 Crai
600 Cr<
9,600
26,300
1948
1957
Tomatoes (Spring)
1948
1957
15,900
18,800
We can see from the above figures that we
have made good gains in production in the
past decade. By using all our know-how and
obtaining better seeds for our crops, we should
be able to make continued progress and im
prove the quality of our crops.
A study of the Annual Reports from our
Florida Experiment Station shows that con
siderable work and effort is being made to
ward improving seed quality. This is as it
should be, for improving the seed we use is
69
quite as important as any other project the
Experiment Station could undertake.
One final word on this subject of adaptabil
ity for our farming conditions. We all know of
crops which will grow well and produce good
quality yields in some areas, but which, for
some unknown reason, will not do well at all
under our crop conditions. With this thought
in mind, our company is experimenting this
year with two types of celery. The first is a
variety grown from Florida-produced seed and
selected for its growth habits. The second is
the original parentage, and has not been
crossed to get hybrid vigor: It is this second
type of celery which is the best we have in
our fields. Both types were planted the same
day, transplanted into the field the same day,
and all other contributing factors were as equal
as we were able to make them.
This problem of seed adaptability is a big
one, and to solve it satisfactorily, all of us in
the industry must work together. A practica\
solution to the seed question is our only means
of staying in the business.
LITERATURE
CITED
1.
Information supplied by Dr. H. G. Hamilton of the
Agricultural Economics Department, University of Florida.
2.
From the Florida Vegetable Crops Statistical Summary
of 1957.
EFFECT OF UREA NITROGEN ON NUTRITIONAL LEAF ROLL
OF TOMATOES
Gaylord M. Volk1
Florida Agricultural Experiment Station
Gainesville
The correlation between nutritional leaf roll
of solanaceous plants and low supply of ni
trate nitrogen in the soil was first brought to
attention by Volk and Gammon (2) as a re
sult of work on Irish potatoes, and by observa
tions on tobacco, tomatoes and certain other
solanaceous crops (3). It appeared that the
roll developed when nitrate nitrogen and am
monia nitrogen were out of balance, and the
plant was using nitrogen primarily in the am
monia form.
Urea nitrogen is a widely used form of fer
tilizer nitrogen, both for direct application to
'Soils Chemist.
Florida
No. 829.
Agricultural
Experiment
Station
Journal
Series.
the soil and as an addition to spray materials
for application to aerial portions-of the plant.
It is important that the effect of urea as com
pared to the effect of ammonia and nitrate be
determined with respect to effect on both,
nutritional leaf roll and the uptake of other
ions, particularly calcium and potassium. Such
information would help to determine whether
the high concentration of the ammonia ion or
the low concentration of the nitrate ion in the
plant is primarily responsible for the leaf roll,
and to what extent the nitrate ion may be in
directly influencing the relative uptake of
various bases such as calcium and potassium.
Typical nutritional leaf roll on potatoes was
shown in a previous publication (2). The de
velopment of leaf roll of tomatoes is typified
by Figure 1. This condition resulted from
planting tomatoes on land that had been in
grass sod for the eleven years previous to turn-
70
FLORIDA STATE HORTICULTURAL SOCIETY, 1958
carboys of fresh solution prepared daily. The
plants were grouped according to size for each
replicate so that results within a replicate
would be comparable.
The solutions used in the study were similar
except for the source of nitrogen used. Each
five gallons of solution contained the follow
ing:
2.8 grams Nitrogen
(variable sources de
pending on treatment)
7.0 grams CaSO, • 2H2O
6.0
"
KHJPO
8.0
"
MgSO, • 7H,,O
51
mgm H3BO3
33
"
MnCL • 4H,,O
4
"
ZnSO4 • 7HaO
1.4
"
CuSO4 • 5H.O
0.4
"
KLMoO4 • 4H2O
90
"
Iron tartrate
Nitrogen sources for the four different solu
tions were as follows:
I Calcium nitrate
Fig. 1.
Typical nutritional leaf roll on tomatoes. These
tomatoes were planted on turned eleven year old sod, and
fertilized at planting with a mixture low in nitrate nitrogen.
.
grew
New leaves are developing free of leaf roll. They
recfollowing application of 70 pounds of nitrate of soda
soc
ommended to correct the condition.
ing for tomatoes. The drill application of fer
tilizer was 1800 pounds per acre of 5-7-5 con
taining 0.75 percent nitrate nitrogen, followed
by a side dressing of 5-0-10 containing only
1.5 percent nitrate nitrogen. The new leaf
development at the top of the plant was free
of the symptoms at the time the pictures were
taken. These leaves developed subsequent to
two side dressings of nitrate of soda totalling
70 pounds per acre. The important factor in
this instance may be that old pasture land was
involved. Previous work has shown that some
soils left in grass sod for several years have
very limited ability to nitrify ammoniacal nitro
gen to nitrate. The same is true of most virgin
and strongly acid soils. (1)
Experimental Procedure
Tomato plants approximately four inches
tall were placed in straight wall funnels, 3.5
inches high and 1.75 inches in diameter, as
shown in Figure 2. Tests were run simultane
ously in triplicate. Each funnel was fitted with
an automatic syphon arrangement that re
moved the liquid from the roots of the plant
at approximately 10 minute intervals and al
lowed the funnel to refill by a slow drip from
II Ammonium nitrate
III Ammonium sulfate
IV Urea
All solutions were approximately pH 5.0.
Results and Conclusions
Relative size of plants after 18 days growth
are shown in Figure 2. Dry weights of plants
and the chemical analyses of the tops are given
in Tables 1 and 2. With the exception of one
plant which made relatively poor growth in
the third replicate of ammonium nitrate the
data for a given treatment are reasonably
consistent considering the fact that they are
single plant tests.
Typical nutritional leaf roll was evident on
plants receiving ammonium sulfate or urea,
but the leaves of plants receiving ammonium
nitrate or calcium nitrate were normal. Figure
3 is a closeup of a plant from the urea treat
ment and shows the leaf roll developing on
the largest leaves. It is interesting to note that
despite the greater plant dry weight and ob
served size of the urea treated plants as com
pared to the ammonium sulfate treated plants,
the total nitrogen uptake from the two ma
terials is relatively constant at .041 grams and
.049 grams, respectively. These are one-half
or less of the quantity found where nitrate
nitrogen was present in the solution. Plants
from the calcium nitrate and ammonium ni
trate
treatments
were
about
equal
in
dry
I
III
Fig. 2.
Calcium nitrate
im&nLwk sarolfate
!
/
Tomato plants growing in rapid flow nutrient solutions.
FLORIDA STATE HORTICULTURAL SOCIETY, 1958
72
weights. Percentage nitrogen was lowest with
urea and highest with ammonium nitrate.
Percentage calcium was consistently low with
the ammonium sulfate and urea treatments
where leaf roll occurred, but total calcium
uptake was considerably higher for urea than
for ammonium sulfate. The effect of the nitrate
ion in mobilizing calcium into the plant may
be the actual reason for the effectiveness of
nitrate nitrogen in preventing leaf roll in the
field. Uptake of phosphorus was lowest per
centage-wise with calcium nitrate and uptake
of potassium was lowest with ammonium ni
trate and ammonium sulfate.
Fig. 3. Effect of urea nitrogen on the development of
nutritional leaf roll. Note the trough-shaped older leaves
typical of the first stages of development of nutritional
leaf roll.
It was anticipated that limited root develop
ment might be observed where leaf roll oc
curred, but this was not the case except for
the ammonium sulfate treatment, where gen
erally limited growth occurred. A comparison
of ammonium nitrate and urea treatments is
particularly interesting because all ions ex
cept those of nitrogen were exactly the same.
Table 1
Effect of Nitrogen Source in Rapid-Flow SolutL on Cultures
on Percentage Composition and Nutritional Leaf Roll of Tomatoes.
Nitrogen
Replication
Source
Calcium
1
2
Nitrate
3
I
Plant Tops
% Ca
Dry Wt.
Qrams
% N
3.29
3.05
3.7U
2.87
3.88
Ave.
1
3.30
2
2.83
3
1.33
Ammonium*
1
2
1.12
1.60
Sulfate
3
II
Ammonium
Nitrate
2TIT9
Ave.
III
IV
Urea*
U.95
iu89
U.UU
HTFo"
3.92
3.22
3^2
% P
% K
3.53
1.12
2.9U
Iu03
T733
3.30
2.15
2.00
U.10
U.U6
2.18
2.5U
1.69
1.58
T7IF
1
2.76
1.81
2.02
2.21
1.86
Aveo
233
2.52
T35
2.05
1755"
L.S.D.
.91
o78
•52
1.81
3
3.60
3.36
2.U0
2.U2
2.30
2.00
1.30
Ave.
2
l.Ul
1.U6
Statistical
value
for
least significant
difference
.91
.95
.82
7m
2.69
1.98
2.08
1.30
1.28
.59
.57
1.50
1735
$
2oll
2.82
1.10
2.58
3.00
3.10
2.75
2.97
.6U
at
.91
27S7
.30
* Nutritional leaf roll was evident where nitrate nitrogen was lacking.
L.S.D.
.36
OF
2725
1.72
Plant
Roots
Wt. Grams
the
5%
point.
.70
.8U
75F
.23
73
VOLK: TOMATO LEAF ROLL
Table 2
Effect of Nitrogen Source on Total Uptake of Nitrogen, Calcium, Phosphorus
and Potassium by Tomatoes
Total Grams in Plant Tops
Dry
Nitrogen
Source
I
Calcium
Nitrate
Replication
Weight
N
1
2
3.29
.100
Nitrate
ITI
IV
Urea
.037
.OUO
K
.097
.103
.080
.107
.100
TiiU
3.30
.151
.138
.072
.072
2iU9
TuZ
7b59
vO5U
705?
1
2
1.12
.oUU
•021
.019
.030
.032
.015
3
.013
.017
3
1
2
3
Av.
Ammonium
Sulfate
.116
.118
P
2.87
2.39
Av.
II
Ammonium
Ca
2T%
2.83
Ia32
1.60
.093
.059
Av.
.^
.052
•028
1.18
1
2
2.76
1.81
1.81
.056
.oUo
.0U6
3
Av.
L.S.D.
.107
.03U
.071
.066
.065
.027
.068
.032
•020
.012
IbiS
.051
.058
.050
.05U
.020
.021
.031
TiUo
.91
•OU6
.021
Tomato plants four inches tall were placed
in straight wall funnels fitted with automatic
syphons to change nutrient solutions every ten
7o93
7526
IoU7
Summary
.037
ToiF
2.13
Use of the other two nitrogen sources re
sulted in variation of calcium and sulfate ions.
Plant growth and the total uptake of nitrogen
and calcium were greater with ammonium
nitrate than with urea, but the total uptake
of potassium was higher and that of phos
phorus about equal for urea, despite the
greater growth with ammonium nitrate. Indi
cations are that the urea was taken into the
plant in a form other than the ammonia ion.
In the process it had a unique effect on the
uptake of associated ions as compared to other
forms of nitrogen.
.035
.0U7
.078
minutes. A complete nutrient solution was
used, but nitrogen was supplied from four
different sources—calcium nitrate, ammonium
nitrate, ammonium sulfate or urea.
Nutritional leaf roll was not present where
nitrate nitrogen was added, but did occur
where urea or ammonium sulfate was used.
Uptake of calcium also was least with these
two treatments. Plant growth was greatest
where nitrate was present and least with am
monium sulfate. Despite the fact that growth
with urea was much greater than with am
monium sulfate, the total nitrogen uptake was
similarly low. With the ammonium nitrate and
urea treatments it was possible to balance
exactly all ions except those of nitrogen. Data
indicate that the urea was taken into the plant
in a form other than ammonia, probably as
74
FLORIDA STATE HORTICULTURAL SOCIETY, 1958
urea itself, and in the process had a unique
effect on the uptake of other ions as compared
to the effect of ammonium nitrate. It appears
that the effect of nitrate nitrogen in mobilizing
calcium into the plant should be given further
consideration in efforts to determine the causes
of nutritional leaf roll of solanaceous plants,
even though the previous work on potatoes
(2) did not indicate that calcium was
factor.
LITERATURE
the
CITED
1.
Shih, Shui-Ho. Factors affecting the nitrifying power
of certain Florida soils. Unpublished thesis, University of
Florida. Sept. 1949.
2.
Volk, G. M. and N. Gammon, Jr. Effect of liming
and fertilization on yield and the correction of nutritional
leaf roll of Irish potatoes. Fla. Agric. Exp. Sta. Bui. 504.
1952.
3.
Volk, G. M. Maintenance of available nitrogen in
Florida soils. Fla. Agric. Exp. Sta. Ann. Rept. 1952. p. 128.
FLORIDA VERSUS CALIFORNIA CELERY IN THE MIDWEST
CONSUMER MARKET
ine quantitatively the nature of the competi
tive relationship between Florida and Cali
fornia celery.
Marshall R. Godwin
Marketing Economist
University of Florida
Method of Procedure
Gainesville
Throughout the harvesting and marketing
season, the Florida celery crop faces direct
competition from California in the market cen
ters of the Eastern United States. Moreover,
from both the standpoint of price and of ap
parent market preference, California celery
has generally occupied the most advantageous
position in the marketplace.
The fundamental role of firms within the
structure of the terminal market is the acquisi
tion of fruit and vegetable supplies in a fash
ion that reflects the desires of the ultimate
consumer. Thus, the manifest preference of
marketing firms for California celery suggests
that the underlying problem confronting the
Florida celery industry stems from the exist
ence of a similar preference on the part of the
consumer.
In
recent
years,
growers
and
marketing
agencies in Florida have demonstrated an in
creasing interest in the nature of the competi
tive relationship between Florida and Cali
fornia celery. This interest stems from an ap
preciation of the fact that one of the first
steps toward improving the economic position
of the Florida celery industry should consist
of an examination of the competitive condi
tions under which the crop is marketed. To
partially meet the informational needs of celery
growers and shippers in connection with this
problem, a study was conducted in the Chi
cago metropolitan area during the spring of
1958. The purpose of this study was to exam
Since primary interest lay in the determina
tion of the degree to which consumers prefer
celery from one producing area over that from
the other, the research procedure employed in
the study entailed the creation of retailing
situations where the homemaker could readily
compare Florida and California celery in the
process of making a buying decision. Within
the market area selected, a series of retail store
tests were conducted in which customers were
afforded an opportunity to choose from either
of two displays containing celery representa
tive of the types produced in Florida and
California.
The test displays of California celery con
sisted of the Utah 52-70 variety, while the
Florida displays were Summer Pascal. Only
celery of the U. S. No. 1 grade was employed
in the market tests. While considerable effort
was devoted to the maintenance of displays
typical of this quality level, equal care was
exercised to assure that the test displays did
not reflect a quality level higher than that
customarily found in U. S. No. 1 celery.
Throughout the study, size 2& celery from
both producing areas was used in the market
ing tests. This size was selected because it ap
proximated the modal group in the total range
of sizes shipped from the two areas during
normal growing seasons.
The fact that consumers may prefer celery
from one producing area over that grown in
another is relevant only when this preference
is established within the price frame of refer-