Citation
Cracked stem of celery caused by a boron deficiency in the soil

Material Information

Title:
Cracked stem of celery caused by a boron deficiency in the soil
Series Title:
Bulletin University of Florida. Agricultural Experiment Station
Creator:
Purvis, E. R ( Ernest Rudolph )
Ruprecht, R. W ( Rudolf William ), b. 1889
Place of Publication:
Gainesville Fla
Publisher:
University of Florida Agricultural Experiment Station
Publication Date:
Language:
English
Physical Description:
16 p. : ill. ; 23 cm.

Subjects

Subjects / Keywords:
Celery -- Diseases and pests -- Florida ( lcsh )
Celery -- Soils -- Florida ( lcsh )
Soils -- Boron content -- Florida ( lcsh )
City of Gainesville ( local )
Boron ( jstor )
Celery ( jstor )
Plant growth ( jstor )
Genre:
bibliography ( marcgt )

Notes

Bibliography:
Bibliography: p. 16.
General Note:
Cover title.
Funding:
Bulletin (University of Florida. Agricultural Experiment Station)
Statement of Responsibility:
by E.R. Purvis and R.W. Ruprecht.

Record Information

Source Institution:
University of Florida
Holding Location:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
027137503 ( ALEPH )
18212974 ( OCLC )
AEN5006 ( NOTIS )

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Full Text



January, 1937


UNIVERSITY OF FLORIDA
AGRICULTURAL EXPERIMENT STATION
GAINESVILLE, FLORIDA
WILMON NEWELL, Director




CRACKED STEM OF CELERY

CAUSED BY A BORON DEFICIENCY IN THE SOIL

By

E. R. PURVIS and R. W. RUPRECHT


Fig. 1.-Effect of excessive and deficient amounts of boron, in comparison
with normal plant. Left, boron injury; center, normal plant; right, boron
deficiency.


Bulletins will be sent free to Florida residents upon application to
AGRICULTURAL EXPERIMENT STATION
GAINESVILLE, FLORIDA


Bulletin 307










EXECUTIVE STAFF
John J. Tigert, M.A., LL.D., President of
the University
Wilmon Newell, D.Sc., Director
H. Harold Hume, M.S., Asst. Dir., Research
Harold Mowry, M.S.A., Asst. Dir., Adm.
J. Francis Cooper, M.S.A., Editor
Jefferson Thomas, Assistant Editor
Clyde Beale, A.B.J., Assistant Editor
Ida Keeling Cresap, Libj ran
Ruby Newhall, Adminj'trative Manager
K. H. Graham, Busin s Manager
Rachel McQuarrie, Accountant

MAIN STATION, GAINESVILLE

AGRONOMY
W. E. Stokes, M.S., Agronomist*
W. A. Leukel, Ph. D., Agronomist
G. E. Ritchey, M.S.A., Associate*
Fred H. Hull, Ph.D., Associate
W. A. Caver, Ph.D., Associate
John P. Camp, M.S., Assistant
ANIMAL HUSBANDRY
A. L. Shealy, D.V.M., Animal Husbandman**
R. B. Becker, Ph. D., Dairy Husbandman
L. M. Thurston, Ph.D., Dairy Technician
WM Neal, Ph.D., Asso. in An. Nutrition
D. A. Sanders, D.V.M., Veterinarian
M. W. Emmel, D.V.M., Veterinarian
N. R. Mehrhof, M.Agr., Poultry Husbandman
W. W. Henley, B.S.A., Asst. An. Husb.*
W. G. Kirk, Ph.D., Asst. An. Husbandman
R. M. Crown, M.S.A., Asst. An. Husbandman
P. T. Dix Arnol', B.S.A., Assistant Dairy
Husbandman
L. L. Rusoff, M.S., Laboratory Assistant
Jeanette Shaw, M.S., Laboratory Technician
CHEMISTRY AND SOILS
R. W. Ruprecht, Ph.D., Chemist**
R. M. Barnette, Ph.D., Chemist
C. E. Bell, Ph.D., Associate
R. B. French, Ph.D., Associate
H. W. Winsor, B.S.A., Assistant
ECONOMICS, AGRICULTURAL
C. V. Noble, Ph.D., Agricultural Economist**
Bruce McKinley, A.B., B.S.A., Associate
Zach Savage, M.S.A., Associate
A. H. Spurlock, M.S.A., Assistant
ECONOMICS, HOME
Ouida Davis Abbott, Ph. D., Specialist**
C. F. Ahmann, Ph.D., Physiologist
ENTOMOLOGY
J. R. Watson, A.M., Entomologist'*
A. N. Tissot, Ph.D., Associate
H. E. Bratley, M.S.A., Assistant
HORTICULTURE
G. H. Blackmon, M.S.A., Horticultur:st and
Acting Head of Department
A. L. Stahl, Ph.D., Associate
F. S. Jamison, Ph.D., Truck Horticulturist
R. J. Wilmot, M.S.A., Specialist, Fumigation
Research
R. D. Dickey, B.S.A., Assistant Horticulturist
PLANT PATHOLOGY
W. B. Tisdale, Ph.D., Plant Pathologist**
George F, Weber, Ph.D., Plant Pathologist
R. K. Vorhees, M.S., Assistant
Erdman West, M. S., Mycologist
Lillian E. Arnold, M.S., Assistant Botanist
Stacy O. Hawkins, M.A., Assistant Plant
Pathologist
SPECTROGRAPHIC LABORATORY
L. W. Gaddum, Ph.D., Biochemist
L. H. Rogers, M.A., Spectroscopic Analyst


BOARD OF CONTROL
Geo. H. Baldwin, Chairman, Jacksonville
Oliver J. Semmes, Pensacola
Harry C. Duncan, Tavares
Thomas W. Bryant, Lakeland
R. P. Terry, Miami
J. T. Diamond, Secretary, Tallahassee

BRANCH STATIONS
NORTH FLORIDA STATION, QUINCY
L. O. Gratz, Ph.D., Plant Pathologist in
Charge
R. R. Kincaid, Ph.D., Asso. Plant Pathologist'
J. D. Warner, M.S., Agronomist
Jesse Reeves, Farm Superintendent
CITRUS STATION, LAKE ALFRED
A. F. Camp, Ph.D., Horticulturist in Charge
John H. Jefferies, Superintendent
W. A. Kuntz, A.M., Assoc. Plant Pathologist
Michael Peech, Ph.D., Soils Chemist
B. R. Fudge, Ph.D., Associate Chemist
W. L. Thompson, B.S., Asst. Entomologist
Walter Reuther, B. S., Asst. Horticulturist
EVERGLADES STATION, BELLE GLADE
A. Daane, Ph.D., Agronomist in Charge
R. N. Lobdell, M.S., Entomologist
F. D. Stevens, B.S., Sugarcane Agronomist
Thomas Bregger, Ph.D., Sugarcane Physiologist
G. R. Townsend, Ph.D., Assistant Plant
Pathologist
J. R. Neller, Ph.D., Biochemist
R. W. Kid er, BS., Assistant Animal
Husbandman
Ross E. Robertson, B.S., Assistant Chemist
B. S. Clayton, B.S.C.E., Drainage Engineer*
SUB-TROPICAL STATION, HOMESTEAD
H. S. Wolfe, Ph. D., Horticulturist in Charge
W. M. Fifield, M.S., Asst. Horticulturist
Geo. D. Ruehle, Ph.D., Associate Plant
Pathologist
W. CENTRAL FLA. STA., BROOKSVILLE
W. F. Ward, M.S.A., Asst. An. Husbandman
in Charge*

FIELD STATIONS
Leesburg
M. N. Walker, Ph.D., Plant Pathologist in
Charge
W. B. Shippy, Ph.D., Asso. Plant Pathologist
K. W. Loucks, M.' S., Asst. Plant Pathologist
J. W. Wilson, Ph.D., Associate Entomologist
C. C. Goff, M.S., Assistant Entomologist
Plant City
A. N. Brooks, Ph.D., Plant Pathologist
Cocoa
A. S. Rhoads, Ph.D., Plant Pathologist
Hastings
A. H. Eddins, Ph.D., Plant Pathologist
Monticello
Asst. Entomologist
Bradenton
David G. Kelbert, Asst. Plant Pathologist
Sanford
E. R. Purvis, Ph.D., Assistant Chemist,
Celery Investigations
Lakeland
E. S. Ellison, Ph.D., Meteorologist*
B. H. Moore, A.B., Asst. Meteorologist*

In cooperation with U.S.D.A.
** Head of Department.










CRACKED STEM OF CELERY

CAUSED BY A BORON DEFICIENCY IN THE SOIL

By

E. R. PURVIS and R. W. RUPRECHT


CONTENTS
Page
Description of the Disease ........... .. .. ... .. 4
E xperim mental ... ..... .......... ...... ... .. .. ........ ..... ..... 5
Sand cultures .... ............................ ...... .... ............... ..... 6
Solution cultures ................. 6....... ..... .... 6
F field tests ........ ............................ .... ....... ..... ... .. 10
Minimum Concentration of Boron Producing Injury .......... 12
D discussion ........ ........................................ ..... ... ......... ... 14
Summary and Conclusion ............. ... .. ......... .. .. 15



INTRODUCTION

Soils utilized for growing celery in Seminole County are
predominantly of the Leon series. Their high state of develop-
ment in this area has resulted from a combination of factors
favorable to the intensive type of culture required in celery
production. The impervious hardpan layer, underlying the sur-
face at a depth varying from one to several feet, provides a
barrier to the downward passage of the irrigation water supplied
from the artesian wells which flow abundantly in the vicinity
of Sanford. This makes possible the system of sub-irrigation
practiced and, coupled with favorable climatic conditions,
accounts for the utilization of such soils for the production of
celery and other truck crops.
Celery growers have long realized that their soils are deficient
in the three major plant nutrients (nitrogen, phosphorus and
potassium) and have fertilized their crops accordingly, often
applying as much as five tons per acre of a 4-5-5 (N-P205-K20)
fertilizer mixture. Skinner and Ruprecht (11)1 found such
heavy applications to be economically profitable. Regardless
of this practice of applying commercial fertilizers in large
quantities, yields of marketable celery have steadily decreased
during the past decade. While all of the causes for this decreased

iFigures (Italic) in parentheses refer to "Literature Cited" in the
back of this bulletin.










CRACKED STEM OF CELERY

CAUSED BY A BORON DEFICIENCY IN THE SOIL

By

E. R. PURVIS and R. W. RUPRECHT


CONTENTS
Page
Description of the Disease ........... .. .. ... .. 4
E xperim mental ... ..... .......... ...... ... .. .. ........ ..... ..... 5
Sand cultures .... ............................ ...... .... ............... ..... 6
Solution cultures ................. 6....... ..... .... 6
F field tests ........ ............................ .... ....... ..... ... .. 10
Minimum Concentration of Boron Producing Injury .......... 12
D discussion ........ ........................................ ..... ... ......... ... 14
Summary and Conclusion ............. ... .. ......... .. .. 15



INTRODUCTION

Soils utilized for growing celery in Seminole County are
predominantly of the Leon series. Their high state of develop-
ment in this area has resulted from a combination of factors
favorable to the intensive type of culture required in celery
production. The impervious hardpan layer, underlying the sur-
face at a depth varying from one to several feet, provides a
barrier to the downward passage of the irrigation water supplied
from the artesian wells which flow abundantly in the vicinity
of Sanford. This makes possible the system of sub-irrigation
practiced and, coupled with favorable climatic conditions,
accounts for the utilization of such soils for the production of
celery and other truck crops.
Celery growers have long realized that their soils are deficient
in the three major plant nutrients (nitrogen, phosphorus and
potassium) and have fertilized their crops accordingly, often
applying as much as five tons per acre of a 4-5-5 (N-P205-K20)
fertilizer mixture. Skinner and Ruprecht (11)1 found such
heavy applications to be economically profitable. Regardless
of this practice of applying commercial fertilizers in large
quantities, yields of marketable celery have steadily decreased
during the past decade. While all of the causes for this decreased

iFigures (Italic) in parentheses refer to "Literature Cited" in the
back of this bulletin.






Florida Agricultural Experiment Station


yield are not known, one cause has been the increase of a non-
parasitic disease described by Foster and Weber in 1924 (3)
as "cracked stem". Stating that the cause of the disease had
not been determined, they believed it to be associated with
unbalanced fertilizer, climatic and moisture conditions. In recent
years this disturbance has be-
come more prevalent throughout
the celery growing districts of
Florida and has been reported
from a number of areas along
the Atlantic seaboard, including
eastern Canada. Often causing
a loss of as much as 50 percent
of the crop, the disease occurs
more frequently on light sandy
soils, usually appearing first on
high, dry spots in the field. How-
ever, the disturbance is not re-
stricted to the poorer soils but
occurs sporadically on even the
best soils.

DESCRIPTION OF THE
DISEASE
The disease first manifests it-
self by a brownish mottling of
the leaf, usually appearing first
along the margins of the bud
leaves. This mottlingis accom-
panied by a brittleness of stem
and by the appearance of brown
stripes in the epidermis above
the vascular bundles of the stalk.
Finally, transverse lesions ap-
pear above the vascular bundles
and the epidermis and adjoining
tissue curl outward from these
breaks. The disrupted tissues
soon become dark brown in color.
This cracking of the stem is well
illustrated in Fig. 2, and by the
Fig. 2.--Cracked stem of celery
plant. plant on the right in Figure 1.







Cracked Stem of Celery


Roots of affected plants also turn brown, the laterals dying
back and forming small knob-like appendages at their extrem-
ities, as shown by the plant to the right in Figure 3. In the

























Fig. 3.-Growth of celery in solution cultures after 21 days with and without
boron. Left, .54 ppm. boron; right, no boron.

final stages, death occurs. However, the final stage is seldom
reached under field conditions, the deformed plant remaining
alive until it is discarded at harvest time. In some cases in the
field, plants may recover and new growth appear free of the
disturbance.
EXPERIMENTAL
Preliminary work indicated that the concentration of the
soil solution influenced the disease and certain facts pointed to a
too high salt concentration as possibly being the actual cause.
The appearance of the disease in experimental field plots which
had received all, or the greater part, of their nitrogen from
readily soluble inorganic sources led to this belief. Plots receiving
similar amounts of nitrogen from the less soluble organic sources
were free of the disturbance. Subsequent experiments, how-






Florida Agricultural Experiment Station


ever, proved that the source of nitrogen had no influence in
preventing the development of cracked stem. Greenhouse work
substantiated this belief for plants grown in nutrient solutions
of high concentration developed the disease, while plants grown
in weaker solutions remained apparently healthy.

SAND CULTURES
In an attempt to determine the optimum concentration of a
nutrient solution for the growth of celery and at the same time
to determine the concentration that would produce cracked stem,
if this was the cause of the disease, a series of 20 sand cul-
tures was set up. Three-gallon glazed stoneware crocks, having
rounded bottoms with one-inch holes for drainage, were filled
with washed builder's sand. Plants similar in size and appear-
ance were set in the crocks on November 27, 1934. Knop's
nutrient solution (6), prepared from chemically pure salts, was
supplied to the cultures by the drip method of Shive and Stahl
(10). Cultures were run in duplicate, the concentration of the
solutions varying by increments of .2, from .2 to 2 percent. One
liter of the solutions, containing one milligram of iron as ferric
chloride, was run through the cultures every 24 hours. The
tests were discontinued after 18 days and at this time all the
plants showed evidence of cracked stem. The plants receiving
the solutions of higher concentration were more seriously af-
fected than those receiving the weaker solutions. A similar
series of cultures employing weaker solutions produced the same
results.
SOLUTION CULTURES

Believing that the salts from the solutions were remaining
in the sand and becoming concentrated there regardless of the
fact that the cultures were leached weekly with a liter of distilled
water, it was decided to substitute solution cultures for the sand
cultures and thus remove this possibility. Accordingly, a series
of 12 solution cultures was begun on January 22, 1935. The first
culture of this series received tap water without any additional
nutrients. The second culture received a .2 percent nutrient
solution. The third culture was the same as the second with
the exception that five milligrams of borax and five milligrams






Cracked Stem of Celery


of zinc sulfate were added to each liter of solution. (These two
salts had produced decided response in field tests during the
previous season.) The remaining nine cultures received solu-
tions varying in concentration from .5 to 1.3 percent by in-
crements of .1 percent. With the exception of the first, all
cultures were supplied with iron at the rate of one milligram
per liter of solution. This series was concluded after 15 days
and at this time only the plant growing in tap water and the
one receiving borax and zinc sulfate were free of cracked stem.
While the tests discussed above were in progress, cracked stem
appeared in 107 of 113 field plots used in fertilizer tests. The
six plots that were free of the disease had received small ap-
plications of borax. Evidence from two sources thus indicated
a boron deficiency as the cause of the disturbance.
To obtain further evidence on this point, a series of 12 solution
cultures was started on February 6, 1935, all solutions being of
.5 percent concentration. Iron was supplied to these cultures
and to the remaining cultures herein reported in the form of
ferric phosphate at the rate of one milligram per liter of solu,
tion. Plants similar in size and appearance were selected and
four treatments were employed in triplicate as recorded in
Table 1. The tests were concluded on March 7, and the plants
were weighed. The results are presented in Table 1.

TABLE 1.-YIELDS OF CELERY IN DIFFERENT SOLUTION CULTURES.


Treatment

.5% Knop's solution in tap
w ater ............... .. .... ...... ........
.5% Knop's solution in distilled
water .................... ..............
.5% Knop's solution in distilled
water .54 ppm. boron from
borax .. ........ .........
.5% Knop's solution in distilled
water 1.14 ppm. zinc from
zinc sulfate ...........................


Yield in grams, green weight
Plant 1 Plant 2 Plant 3 Average

13.9 9.3 7.8 10.3

20.2 16.5 17.8 18.2


23.2 28.1 26.7 26.0


16.3 19.9 12.9 16.4


With the exception of those receiving boron, all plants of
this series had cracked stem when the experiment was concluded.






Florida Agricultural Experiment Station


The results show that the boron solution plants had excellent
white root systems in contrast to the short, stubby, brown roots
of the diseased plants. Cracked stem occurred in the plants
grown in tap water with nutrients added where, as previously
mentioned, it had failed to appear when plants were grown in
tap water alone. It is believed that the tap water contained
sufficient boron to provide for the growth permitted by its limited
nutrient content, but not enough for the increased growth pro-
moted by the addition of nutrients. The plants receiving zinc
showed no resistance to the disturbance.
Table 2 presents results from another series of solution cul-
tures in which boron was supplied in increasing amounts. Again
the plants .which did not receive boron developed cracked -stem
while plants supplied with the element remained healthy. In-
creased amounts of boron did not increase growth. The tests
were conducted over a period of 21 days using .5 percent Knop's
solution in distilled water in all cultures.

TABLE 2.-YIELDS OF CELERY IN SOLUTION CULTURES WITH AND WITHOUT
ADDITION OF BORON.

Treatment Yield in grams, green weight
Plant 1 Plant 2 Plant 3 Average
No boron ........ ............ ............ 16.03 12.30 13.50 13.90
.54 ppm. boron ................... 19.45 18.45 19.70 19.20
1.08 ppm. boron ........................ 13.65 21.10 11.10 15.30
1.62 ppm. boron ...................... 19.15 16.40 16.47 17.30



For the purpose of studying the recovery of plants affected
with cracked stem, and to obtain further data concerning the
amount of boron required for optimum growth of celery, the
plants used in the preceding series of cultures were rearranged
as shown in Table 3. The plant used in culture 4 of the new
series replaced one of the plants receiving 1.62 parts per million
of boron in the preceding series. The substituted plant was of
the same age as the others and showed extreme symptoms of
boron deficiency.







Cracked Stem of Celery


TABLE 3.-SOUTION CULTURES SHOWING RESIDUAL EFFECT OF BORON
ON CELERY.

Treatment Previous Green wt. Green wt. Gain in wt.
3/30/35 treatment in grams in grams in grams
3/7/35-3/30/35 3/30/35 5/7/35
1. No boron ........ No boron ........ 16.03 20.30 4.27
2. No boron .......... No boron ........! 12.30 23.70 11.40
3. 1.08 ppm. boron iNo boron ......... 13.50 22.20 8.70
4. 1.08 ppm. boron No boron ....... 13.40 23.50 10.10
5. No boron .......... .54 ppm. boron 19.45 78.75 59.30
6. No boron .........' 1.62 ppm. boron 19.15 76.70 57.55
7. 2.16 ppm. boron .54 ppm. boron i 18.55 53.50 34.95
8. 2.16 ppm. boron 1.08 ppm. boron I 21.10 106.60 85.50
9. 3.24 ppm. boron 1.08 ppm. boron 13.65 66.00 52.35
10. 3,24 ppm. boron 1.62 ppm. boron 16.40 85.65 69.25
11. 4.32 ppm. boron .54 ppm. boron 19.70 51.65 31.65
12. 4.32 ppm. boron 1.08 ppm. boron 11.10 58.20 58.20

.5% Knop's solution used in all cultures.

These tests were conducted over a period of 37 days and the
results are more conclusive than those reported in Tables 1
and 2. The plants of the first four cultures showed definite
evidence of cracked stem when the tests were begun. When
concluded, those in cultures 1 and 2 were dead. The plants in
cultures 3 and 4 were showing definite signs of recovery, al-
though their gain in weight was no greater than that of the
two preceding plants. Both of these plants had excellent white
root systems, and although the bud of the plant in culture 3 was
dead, several new buds had formed and were beginning to de-
velop new leaf stalks.
The recovery of these two plants is in line with field observa-
tions of recovery where new growth appears free of the disease.
Unaided field recovery is probably due to changes in the soil
environment which bring boron into solution, or which cause
the cessation of rapid growth and therefore decrease the demand
upon the boron-deficient soil solution.
The plants in cultures 5 and 6 apparently retained sufficient
boron from their previous treatment, as both made good growth







Florida Agricultural Experiment Station


and remained free of cracked stem. The higher boron concen-
trations produced no greater growth than did the solution con-
taining the lowest concentration.

FIELD TESTS WITH BORON

The beneficial effect of 10 pounds per acre applications of borax
was noted in field plots during the spring of 1934. However, as
none of the untreated plots developed cracked stem no relation-
ship between this response and cracked stem was recognized.
During the 1934-1935 season, borax was applied to plots in 10
fields in Seminole County. Uniform distribution was obtained
by spraying a weak solution of borax (10 pounds of borax to

TABLE 4.-EFFECT OF BORAX ON YIELD OF CELERY (1934-1935).


Treatment per acre


10 lbs. borax .................
10 lbs. borax ...........
20 Ibs. borax ...............
20 lbs. borax ..................
30 lbs. borax .................
30 lbs. borax ..... .............
No treatment ................
No treatment ................-
No treatment .................

10 lbs. borax ..................
No treatment ..................

10 lbs. borax ....................
No treatment .............

10 Ibs. borax ....................
No treatment ....................

20 lbs. borax ....................
No treatment ...................


Field
No.

1








2

3

4

5

6

7


Date of harvest


2/28/35
2/28/35
2/28/35
2/28/35
2/28/35
2/28/35
2/28/35
2/28/35
2/28/35

3/11/35
3/11/35

3/12/35
3/12/35

3/25/35
3/25/35

3/25/35
3/25/35

3/25/35
3/25/35

3/27/35
3/27/35

4/2/35
4/2/35

4/16/35
4/16/35

5/2/35
5/2/35


Yield per 100 ft.
of row

305 pounds
279 pounds
331 pounds
315 pounds
321 pounds
338 pounds
127 pounds
62 pounds
85 pounds

170 pounds
161 pounds

248 pounds
208 pounds

273 pounds
257 pounds

246 pounds
175 pounds

373 pounds
282 pounds

188 pounds
179 pounds

241 pounds
197 pounds

259 pounds
221 pounds

371 pounds
333 pounds


10 Ibs. borax .................
No treatment ..................

10 lbs. borax .................
No treatment ...................

10 lbs. borax ................
No treatment ...........

10 lbs. borax ..................
No treatment .............

10 Ibs. borax ...................
No treatment ..... .........


I







Cracked Stem of Celery


100 gallons of water) directly on the soil in close proximity to
the base of the plants. The borax was applied approximately
two weeks after the plants were set in the field. Table 4 pre-
sents data obtained from these tests. The yields are for the
marketable celery from the two center rows of four-row plots.
In these tests an increase in marketable celery was obtained
in all fields where boron was applied. Cracked stem occurred in
the control plots in fields 1 and 9 but did not appear in any of
the other untreated plots. The increase in yield obtained from
the application of boron in these tests indicates that the crack-
ing of the stem is an extreme symptom of boron deficiency, and
that the celery yields may be considerably lowered without plant
deformation becoming apparent. In field 1, the 20 and 30 pounds
per acre applications produced decided injury in a number of
plants. However, yields from these plots were progressively
higher than from the plots receiving 10 pounds of borax per acre.
Boron injury is characterized by a deep greening and marked
crinkling of the leaves, and by the production of long, spindly
ribs. These symptoms are well illustrated by the plant on the
left in Figure 1.
With the exception of the second "no treatment" plot, the
plots of field 1, as listed in Table 4, were employed in further
tests during the 1935-1936 season in order to study the residual
effect of boron in the soil. Three additional plots in which
cracked stem occurred during the 1934-1935 season and which
had not received boron were included in this series to determine


TABLE 5.-RESIDUAL EFFECT


Per acre
treatment
in 1934

No borax ......
No borax ....... ...-
No borax ..... .
No borax ......... ...
No borax ..... .
No borax

10 Ibs. borax --. ..--
10 lbs. borax ...

20 lbs. borax ..........
20 lbs. borax ........
30 lbs. borax ........
30 lbs. borax ........


Yield per 100
ft. of row
2/28/35

127 lbs.
194 lbs.
85 lbs.
No celery
132 lbs.
305 lbs.
279 lbs.

331 lbs.
315 lbs.
321 lbs.
338 lbs.


ON CELERY OF BORAX IN THE SOIL.
Per acre Yield per
treatment 100 feet
in 19351 of row

No borax ............. 199 lbs.
No borax .................. 216 lbs.
10 lbs. borax .. ...... 226 lbs.
40 lbs. borax .........- 336 lbs.
50 lbs. borax ........... 246 lbs.


10 lbs. borax ..........
No borax .................

20 lbs. borax .........
No borax ................
30 lbs. borax ...........
No borax ................


263 Ibs.
178 lbs.

224 lbs.
254 lbs.
260 lbs.
258 lbs.


Plants harvested 3/2/36.


- -- -- i - - L _


I


lBorax applied 10/22/35.






Florida Agricultural Experiment Station


the effect of heavier single applications of borax. Results ob-
tained from these tests are presented in Table 5.
The data presented in Table 5 bring out some interesting
results. During the 1935-36 season, the 40 and 50 pounds per
acre applications of borax did not produce as severe injury as
was produced by 30 pounds per acre applications during the pre-
vious season. It will be noted from the table that the plot re-
ceiving the 40 pounds per acre application actually produced the
highest yield of all. Some injury was present in this plot and
more in the plot to which 50 pounds per acre of borax was
applied. However, the injury was seldom serious enough to
cause the plants to be discarded. Cracked stems were present
in the two plots which were untreated during both seasons and
also in the plot receiving 10 pounds per acre of borax in 1934
but no borax the following season. The plots receiving 20 and
30 pounds of borax per acre in 1934 and no treatment during
the following season evidently retained sufficient boron for plant
needs. No evidence of cracked stem was apparent in these
plots and the yields were as high as in the plots where similar
amounts of borax were applied during both seasons.
Rainfall during the 1935-36 season was abnormally.heavy and
this undoubtedly accounts for the absence of more serious injury
in the plots receiving the heavier borax applications. Either the
boron was leached from the soil or entered into insoluble com-
binations and became unavailable to the plants. It is probable
that both of these factors played a part in removing the element
from the soil solution.
Data presented in Table 5 indicate that the light sandy Leon
soils in Seminole County will require annual applications of
borax at the rate of 10 pounds per acre for maximum production
of celery. In the case of peats and heavier soils it is believed
that similar applications every second or third year will suffice.
Limited data from tests on the organic soils of Oviedo and Sara-
sota areas indicate that boron remains available in these soils
even after heavy rains.

MINIMUM CONCENTRATION OF BORON PRODUCING
INJURY TO CELERY
To determine the minimum boron concentration necessary to
produce injury to celery, a series of solution cultures was started
on February 29, 1936. The boron content of the solutions varied







Cracked Stem of Celery


from .54 to 43.2 milligrams per liter. A .5 percent Knop's
solution was used in all cultures. Because of the possibility of
luxury consumption of boron and the resulting confusion as to
the actual quantity of the element producing toxicity, continu-
ous solution renewal was not supplied to these cultures. The
cultures were kept at constant volume by the addition of distilled
water, and the nutrients of Knop's solution were added to all
cultures in similar small amounts twice during the tests. An
outline of the treatments and the results are listed in Table 6.
The cultures receiving boron in the above series produced
normal growth until the concentration of this element exceeded
10.8 parts per million. Definite injury was produced by 16.2
parts per million. As this is approximately the concentration
that would exist in the soil solution where 30 pounds per acre
applications of borax are made in the field, these results are
in close agreement with the field observations of boron injury
reported in the discussion of Table 4. This statement is based
upon the assumption of a 10 percent moisture content in the
soil, and the complete solution of the 30 pounds of borax.

TABLE 6.-EFFECT OF VARYING AMOUNTS OF BORON ON GROWTH OF CELERY
IN SOLUTION CULTURES.

Treatment in
milligrams of Wt. of plants Wt. of plants Gain in weight
boron per liter 2/29/36 5/10/36

No boron 1.25 gms. 2.45 gms. 1.20 gms.
.54 2.00 gms. 30.00 gms. 28.00 gms.
1.08 1.85 gms. 19.85 gms. 18.00 gms.
2.16 1.55 gms. 26.70 gms. 25.15 gms.
3.24 2.25 gms. 23.50 gms. 21.25 gms.
4.32 2.20 gms. 21.00 gms. 18.80 gms.
5.40 2.18 gms. 19.34 gms. 17.16 gms.
10.80 3.32 gms. 32.33 gms. 29.01 gms.
16.20 2.65 gms. 11.24 gms. 8.59 gms.
21.60 1.75 gins. 4.16 gms. 2.41 gms.
32.40 2.33 gms. 7.30 gms. 4.97 gms.
43.20 1.95 gms. 8.40 gms. 6.45 gms.






Florida Agricultural Experiment Station


NITROGEN CONTENT OF NORMAL AND
DISEASED PLANTS
Samples of normal and diseased plants were collected from
the same field and analyzed. The only constant difference found
in these analyses was that the diseased plants contained less
total nitrogen than did the normal plants, as is shown in Table 7.
The low nitrogen content of the diseased plants indicates that
a boron deficiency affects the protein metabolism of the plant.
Shive (9) has presented strong evidence that such is the case
with the cotton plant.

TABLE 7.-NITROGEN CONTENT OF NORMAL AND CRACKED STEM CELERY.

Portion of plant Normal plant Cracked stem
plant
%N. %N.
Roots .. ........ .......... ...... ........... ... 2.00 1.92
Roots .. .. ... ........................ ...... .... 2.28 1.75
Stems -.... ............ .................. ............ 2.45 2.18
Stem s ... ... ......... .............. ......... 2.59 2.28
Leaves ........................... 4.55 4.35
Leaves ............... ......... ............ ... .... 4.65 4.10
Stems and leaves ........................... -.......... 3.30 3.12
Stems and leaves (boron treated) ....-....- 3.39


DISCUSSION
No attempt will be made to present a complete historical
background of the work dealing with the role of boron in plant
nutrition. Agulhon (1) in 1910 reported that small amounts
of boron produced beneficial effects upon the growth of higher
plants. Brenchley (2), Haas (4, 5), McHargue and Calfee (7),
and more recently Shive (9), have shown that boron is essential
to the growth of a number of plants. It is likely that all plants
require the element, the amount needed depending upon the
species. Other investigators have found that from .5 to 1 part
per million of boron in solution cultures is sufficient for most
plant growth; the results with celery falling within this range.
However, the celery plant possesses a much higher tolerance
for boron than has been reported for most of the plants used in
similar studies. Although .54 parts per million of the element






Florida Agricultural Experiment Station


NITROGEN CONTENT OF NORMAL AND
DISEASED PLANTS
Samples of normal and diseased plants were collected from
the same field and analyzed. The only constant difference found
in these analyses was that the diseased plants contained less
total nitrogen than did the normal plants, as is shown in Table 7.
The low nitrogen content of the diseased plants indicates that
a boron deficiency affects the protein metabolism of the plant.
Shive (9) has presented strong evidence that such is the case
with the cotton plant.

TABLE 7.-NITROGEN CONTENT OF NORMAL AND CRACKED STEM CELERY.

Portion of plant Normal plant Cracked stem
plant
%N. %N.
Roots .. ........ .......... ...... ........... ... 2.00 1.92
Roots .. .. ... ........................ ...... .... 2.28 1.75
Stems -.... ............ .................. ............ 2.45 2.18
Stem s ... ... ......... .............. ......... 2.59 2.28
Leaves ........................... 4.55 4.35
Leaves ............... ......... ............ ... .... 4.65 4.10
Stems and leaves ........................... -.......... 3.30 3.12
Stems and leaves (boron treated) ....-....- 3.39


DISCUSSION
No attempt will be made to present a complete historical
background of the work dealing with the role of boron in plant
nutrition. Agulhon (1) in 1910 reported that small amounts
of boron produced beneficial effects upon the growth of higher
plants. Brenchley (2), Haas (4, 5), McHargue and Calfee (7),
and more recently Shive (9), have shown that boron is essential
to the growth of a number of plants. It is likely that all plants
require the element, the amount needed depending upon the
species. Other investigators have found that from .5 to 1 part
per million of boron in solution cultures is sufficient for most
plant growth; the results with celery falling within this range.
However, the celery plant possesses a much higher tolerance
for boron than has been reported for most of the plants used in
similar studies. Although .54 parts per million of the element






Cracked Stem of Celery


produces normal growth in solution cultures, 20 times this
amount is not toxic to the plant.
The fact that cracked stem of celery has become quite com-
mon in practically every celery growing area in the eastern
part of the United States and Canada indicates that the celery
plant is a gross boron feeder. The depletion of the element from
such a wide variety of soils can hardly be explained otherwise.
How large a part the use of more concentrated or refined fer-
tilizer salts has played in bringing about this deficiency is dif-
ficult to state. Once the deficiency has been established, the
use of the usual fertilizer mixtures, even those containing crude
materials, will hardly supply enough of this element to produce
normal plant growth.

SUMMARY AND CONCLUSIONS
Cracked stem of celery is described and shown to be a symptom
of boron deficiency in the soil. The disturbance is prevented
by the application of commercial borax at the rate of 10 pounds
per acre. The borax should be applied to the soil, in close prox-
imity to the base of the plant, approximately two weeks after
the plants are set in the field. Probably the simplest and best
way to supply such small amounts of borax is in solution. Good
results have been obtained by using spray machines. By remov-
ing the disks and adjusting the nozzles so that a stream of the
solution is sprayed close to the plants from both sides, this
method offers a very satisfactory means of getting even distribu-
tion. Such an application not only prevents the appearance of
cracked stem, but also produces a decided increase in yield of
marketable celery on soils deficient in boron. Indications are
that the borax will have to be applied annually to the light sandy
soils, and every second or third year to peats and heavier mineral
soils. Heavier applications than 10 pounds per acre are not
recommended, due to the danger of toxic conditions developing.
Solution culture studies have shown that .54 parts per million
of boron in the nutrient solution produces normal growth of
celery. Twenty times this amount does not produce plant in-
jury but decided toxicity appears when the concentration is
increased to 16.2 parts per million.







Florida Agricultural Experiment Station


LITERATURE CITED

1. AGULHON, H. Emploi du bore comme engrais catalytique. Compt.
Rend. Acad. Sci. (Paris), 150, No. 5, pp. 288-291. 1910.

2. BRENCHLEY, W. E. Investigations of the effect of boron on plant life.
Agr. Prog. (Agr. Ed. Assoc., London) pp. 104-105. 1926.

3. FOSTER, A. C., and G. F. WEBER. Celery diseases in Florida. Fla.
Agr. Exp. Sta. Bul. 173, pp. 58-59. 1924.

4. HAAS, A. R. C. Effects of boron on the growth of citrus. Cal. Citrogr.
14: 9: 355. 1929.

5. HAAS, A. R. C, and L. J. KLOTZ. Some anatomical and physiological
changes in citrus produced by boron deficiency. Hilgardia (Calif.
Sta.) 5.8: 175-196. 1931.

6. KNOP, W. Quantitative-analytische Arbeiten Oiber den Ernihrungs-
process der Pflanzen. 11. Landw. Versuchsst. 4: 173-187. 1862.

7. MCHARGUE, J. S., and R. K. CALFEE. Further evidence that boron is
essential for the growth of lettuce. Plant Physiol. 8: 2: 305-313.
1933.

8. McMURTREY, J. E., JR. The effect of boron deficiency on the growth of
tobacco plants in aerated and unaerated solutions. Jour. Agr. Res.
38: 7: 371-380. 1929.

9. SHIVE, J. W. The adequacy of the boron and manganese content of
natural nitrate of soda to support plant growth in sand cultures.
N. J. Agr. Exp. Sta. Bul. 603. 1936.

10. SHIVE, J. W., and A. L. STAHL. Constant rates of continuous solution
renewal for plants in water cultures. Botanical Gazette 84: 3: 317-
323. 1927.

11. SKINNER, J. J., and R. W. RUPRECHT. Fertilizer experiments with
truck crops. Fla. Agr, Exp. Sta. Bul. 218. 1930.

12. SOMMER, A. L., and H. SOROKIN. Effects of the absence of boron and
of some other essential elements on the cell and tissue structure of
the root tips of Pisum sativum. Plant Physiol. 3: 237-260. 1928.