• TABLE OF CONTENTS
HIDE
 Front Cover
 Credits
 Table of Contents
 Introduction
 Symptoms
 Experiments
 Varietal susceptibility
 Foliage analysis
 Soils
 Effects of other elements
 Recommendations for control
 Summary
 Literature cited














Group Title: Bulletin - University of Florida Agricultural Experiment Station ; 447
Title: Copper deficiency of tung in Florida
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00027593/00001
 Material Information
Title: Copper deficiency of tung in Florida
Series Title: Bulletin - University of Florida Agricultural Experiment Station ; 447
Physical Description: Book
Language: English
Creator: Dickey, R. D.
Drosdoff, Matthew
Hamilton, Joseph
Publisher: University of Florida Agricultural Experiment Station
Publication Date: 1948
 Record Information
Bibliographic ID: UF00027593
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.

Table of Contents
    Front Cover
        Page 1
    Credits
        Page 2
        Page 3
    Table of Contents
        Page 4
    Introduction
        Page 5
    Symptoms
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
    Experiments
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
    Varietal susceptibility
        Page 22
    Foliage analysis
        Page 23
    Soils
        Page 24
    Effects of other elements
        Page 25
        Page 26
    Recommendations for control
        Page 27
        Page 28
        Page 29
    Summary
        Page 30
    Literature cited
        Page 31
        Page 32
Full Text



Bulletin 447


UNIVERSITY OF FLORIDA
AGRICULTURAL EXPERIMENT STATION
HAROLD MOWRY, Director
GAINESVILLE, FLORIDA






(In Cooperation with U. S. Department of Agriculture)



COPPER DEFICIENCY OF

TUNG IN FLORIDA

By R. D. DICKEY, MATTHEW DROSDOFF and JOSEPH HAMILTON














Fig. 1.-Typical copper-deficient and normal tung leaves. From left to
right: 1, cupping, chlorosis and marginal burn; 2, chlorosis, marginal burn
and ragged margin and holes; 3, normal leaf.




Single copies free to Florida residents upon request to
AGRICULTURAL EXPERIMENT STATION
GAINESVILLE, FLORIDA


September, 1948









BOARD OF CONTROL

J. Thos. Gurney, Chairman, Orlando
N. B. Jordan, Quincy
Thos. W. Bryant, Lakeland
J. Henson Markham, Jacksonville
Hollis Rinehart, Miami
W. F. Powers, Secretary, Tallahassee


EXECUTIVE STAFF
J. Hillis Miller, Ph.D., President of the
University3
H. Harold Hume, D.Sc., Provost for Agr.'
Harold Mowry, M.S.A., Director
L. O. Gratz, Ph.D., Asst. Dir., Research
W. M. Fifield, M.S., Asst. Dir., Admin.
J. Francis Cooper, M.S.A., Editor3
Clyde Beale, A.B.J., Associate Editors
Ida Keeling Cresap, Librarian
Ruby Newhall, Administrative Managers
Geo. F. Baughman, M.A., Business Managers
Claranelle Alderman, Accountants


MAIN STATION, GAINESVILLE

AGRICULTURAL ENGINEERING
Frazier Rogers, M.S.A., Agr. Engineer'
J. M. Johnson, B.S.A.E., Asso. Agr. Engineers
J. M. Myers, B.S., Asso. Agr. Engineer
R. E. Choate, B.S.A.E., Asst. Agr. Engineers
A. M. Pettis, B.S.A.E., Asst. Agr. Engineer2 8

AGRONOMY
Fred H. Hull, Ph.D., Agronomist
G. E. Ritchey, M.S., Agronomist2
G. B. Killinger, Ph.IY., Agronomists
H. C. Harris, Ph.D., Agronomist3
R. W. Bledsoe, Ph.D., Agronomist
M. E. Paddick, Ph.D., Agronomist
S. C. Litzenberger, Ph.D., Associate
W. A. Carver, Ph.D., Associate
Fred A. Clark, B.S., Assistant

ANIMAL INDUSTRY
A. L. Shealy, D.V.M., An. Industrialist s
R. B. Becker, Ph.D., Dairy Husbandman3
E. L. Fouts, Ph.D., Dairy Technologists
D. A. Sanders, D.V.M., Veterinarian
M. W. Emmel, D.V.M. Veterinarian3
L. E. Swanson, D.V.M., Parasitologist
N. R. Mehrhof, M.Agr., Poultry Husb.3
G. K. Davis, Ph.D., Animal Nutritionists
R. S. Glasscock, Ph.D., An. Husbandman3
P. T. Dix Arnold, M.S.A., Asst. Dairy Husb.8
C. L. Comar, Ph.D., Asso. Biochemist
L. E. Mull, M.S., Asst. in Dairy Tech.
Katherine Boney, B.S., Asst. Chem.
J. C. Driggers, B.S.A., Asst. Poultry Husb.3
Glenn Van Ness, D.V.M., Asso. Poultry
Pathologist
S. John Folks, B.S.A., Asst. An. Husb.3
W. A. Krienke, M.S., Asso. in Dairy Mfs.s
S. P. Marshall, Ph.D., Asso. Dairy Husb.3
C. F. Simpson, Y.V.M., Asso. Veterinarian
C. F. Winchester, Ph.D., Asso. Biochemists


ECONOMICS, AGRICULTURAL
C. V. Noble, Ph.D., Agri. Economist'3
Zach Savage, M.S.A., Associate
A. H. Spurlock, M.S.A., Associate
D. E. Alleger, M.S., Associate
D. L. Brooke, M.S.A., Associate
R. E. L. Greene, Ph.D., Agri. Economist
H. W. Little, M.S., Assistant

Orlando, Florida (Cooperative USDA)
G. Norman Rose, B.S., Asso. Agr. Economist
J. C. Townsend, Jr., B.S.A., Agr. Statisticians
J. B. Owens, B.S.A., Agr. Statisticians
J. F. Steffens, Jr., B.S.A., Agr. Statisticians

ECONOMICS, HOME
Ouida D. Abbott, Ph.D., Home Econ.1
R. B. French, Ph.D., Biochemist

ENTOMOLOGY
A. N. Tissot, Ph.D.. Entomologist'
L. C. Kuitert, Ph.D., Assistant
H. E. Bratley, M.S.A., Assistant

HORTICULTURE
G. H. Blackmon, M.S.A., Horticulturist'
F. S. Jamison, Ph.D., Horticulturists
H. M. Reed, B.S., Chem., Veg. Processing
Byron E. Janes, Ph.D., Asso. Hort.
R. A. Dennison, Ph.D., Asso. Hort.
R. K. Showalter, M.S., Asso. Hort.
Albert P. Lorz, Ph.D., Asso. Hort.
R. H. Sharpe, M.S., Asso. Hort.
R. J. Wilmot, M.S.A., Asst. Hort.
R. D. Dickey, M.S.A., Asst. Hort.
Victor F. Nettles, M.S.A., Asst. Hort.4
F. S. Lagasse, Ph.D., Asso. Hort.2
L. H. Halsey, B.S.A., Asst. Hort.
F. E. Myers, B.S.A., Asst. Hort.

PLANT PATHOLOGY
W. B. Tisdale, Ph.D., Plant Pathologist'
Phares Decker, Ph.D., Asso. Plant Path.
Erdman West, M.S., Mycologist and Botanist
Howard N. Miller, Ph.D., Asso. Plant Path.
Lillian E. Arnold, M.S., Asst. Botanist
SOILS
F. B. Smith, Ph.D., Microbiologist1s
Gaylord M. Volk, Ph.D., Chemist
J. R. Henderson, M.S.A., Soil Technologists
J. R. Neller, Ph.D., Soils Chemist
Nathan Gammon, Jr., Ph.D., Soils Chemist
C. E. Bell, Ph.D., Associate Chemist
R. A. Carrigan, Ph.D., Asso. Biochemists
H. W. Winsor, B.S.A., Assistant Chemist
Geo. D. Thornton, Ph.D., Asso. Microbiologists
R. E. Caldwell, M.S.A., Asst. Chemists
J. B. Cromartie, B.S.A., Soil Surveyor
Ralph G. Leighty, B.S., Asso. Soil Surveyor
V. W. Cyzycki, B.S., Asst. Soil Surveyor
R. B. Forbes, M.S., Asst. Soils Chemist
W. L. Pritchett, M.S., Asst. Chemist
Jean Beem, B.S.A., Asst. Soil Surveyor

1 Head of Department.
SIn cooperation with U. S.
Cooperative, other divisions, U. of F.
4 On leave.











BRANCH STATIONS

NORTH FLORIDA STATION, QUINCY
J. D. Warner, M.S., Vice-Director in Charge
R. R. Kincaid, Ph.D., Plant Pathologist
W. H. Chapman, M.S., Asso. Agron.
R. C. Bond, M.S.A., Asso. Agronomist
L. G. Thompson, Ph.D., Soils Chemist
Frank S. Baker, Jr., B.S., Asst. An. Hush.
Kelvin Dorward, M.S., Entomologist

Mobile Unit, Monticello
R. W. Wallace, B.S., Associate Agronomist

Mobile Unit, Marianna
R. W. Lipscomb, M.S., Associate Agronomist

Mobile Unit, Wewahitchka
J. B. White, B.S.A., Associate Agronomist

Mobile Unit, DeFuniak Springs
R. L. Smith, M.S., Associate Agronomist

CITRUS STATION, LAKE ALFRED
A. F. Camp, Ph.D., Vice-Director in Charge
W. L. Thompson, B.S., Entomologist
J. T. Griffiths, Ph.D., Asso. Entomologist
R. IY. Suit, Ph.D., Plant Pathologist
E. P. Ducharme, M.S., Plant Pathologist4
R. K. Voorhees, M.S., Asso. Horticulturist
C. R. Stearns, Jr., B.S.A., Asso. Chemist
James K. Colehour, M.S., Asst. Chemist
T. W. Young, Ph.D., Asso. Horticulturist
J. W. Sites, M.S.A., Horticulturist
H. O. Sterling, B.S., Asst. Horticulturist
J. A. Granger, B.S.A., Asst. Horticulturist
H. J. Reitz, M.S., Asso. Horticulturist
Francine Fisher, M.S., Asst. Plant Path.
I. W. Wander, Ph.D., Soils Chemist
A. E. Willson, B.S.A., Asso. Biochemist
J. W. Kesterson, M.S., Asso. Chemist
R. N. Hendrickson, B.S., Asst. Chemist
E. H. Bitcover, M.A., Soils Chemist
L. C. Knorr, Ph.D., Asso. Histologist
Joe P. Barnett, B.S.A., Asst. Horticulturist
J. C. Bowers, B.S., Asst. Chemist
D. S. Prosser, Jr., B.S., Asst. Horticulturist
R. W. Olsen, B.S., Biochemist
F. W. Wenzel, Jr., Ph.D., Supervisory Chem.

EVERGLADES STATION, BELLE GLADE
R. V. Allison, Ph.D., Vice-Director in Charge
F. D. Stevens, B.S., Sugarcane Agronomist
Thomas Bregger, Ph.D., Sugarcane
Physiologist
J. W. Randolph, M.S., Agricultural Engineer
W. T. Forsee, Jr., Ph.D., Chemist
R. W. Kidder, M.S., Asso. Animal Hush.
T. C. Erwin, Assistant Chemist
Roy A. Bair, Ph.D., Agronomist
C. C. Seale, Asso. Agronomist
N. C. Hayslip, B.S.A., Asso. Entomologist
E. H. Wolf, Ph.D., Asst. Horticulturist
W. H. Thames, M.S., Asst. Entomologist
J. C. Hoffman, M.S., Asso. Horticulturist


C. B. Savage, M.S.A., Asst. Horticulturist
D. L. Stoddard, Ph.D., Asso. Plant Path.
W. A. Desnoyers, B.S., Asst. Hydrologist


SUB-TROPICAL STATION, HOMESTEAD

Geo. D. Ruehle, Ph.D., Vice-Dir. in Charge
D. O. Wolfenbarger, Ph.D., Entomologist
Francis B. Lincoln, Ph.D., Horticulturist
Robt. A. Conover, Ph.D., Asso. Plant Path.
R. W. Harkness, Ph.D., Asst. Chemist
Milton Cobin, B.S., Asso. Horticulturist

W. CENT. FLA. STATION, BROOKSVILLE

William Jackson, B.S.A., Animal Husband-
man in Charge2


RANGE CATTLE STATION, ONA

W. G. Kirk, Ph.D., Vice-Director in Charge
E. M. Hodges, Ph.D., Associate Agronomist
D. W. Jones, B.S., Asst. Soil Technologist
H. J. Fulford, B.S.A. Asst. Animal Husb.

CENTRAL FLORIDA STATION, SANFORD

R. W. Ruprecht, Ph.D., Vice-Dir. in Charge
J. W. Wilson, Sc.D., Entomologist
Ben F. Whitner, Jr., B.S.A., Asst. Hort.


WEST FLORIDA STATION, MILTON

H. W. Lundy, B.S.A., Associate Agronomist


FIELD STATIONS

Leesburg
G. K. Parris, Ph.D., Plant Path. in Charge

Plant City
A. N. Brooks, Ph.D., Plant Pathologist

Hastings
A. H. Eddins, Ph.D., Plant Path. in Charge
E. N. McCubbin, Ph.D., Horticulturist

Monticello
A. M. Phillips, B.S., Asso. Entomologist2

Bradenton
J. R. Beckenbach, Ph.D., Hort. in Charge
E. G. Kelsheimer, Ph.D., Entomologist
David G. Kelbert, Asso. Horticulturist
E. L. Spencer, Ph.D., Soils Chemist
Robert 0. Magie, Ph.D., Gladioli Hort.
J. M. Walter, Ph.D., Plant Pathologist
Donald S. Burgis, M.S.A., Asst. Hort.

Lakeland
Warren O. Johnson, B.S., Meteorologist2

1Head of Department.
In cooperation with U. S.
3 Cooperative, other divisions, U. of F.
4On leave.














CONTENTS


Page

INTRODUCTION ........-..--......-...- ----... .. ...... --------- 5



SYMPTOMS -...~...-- --....-......-....----.... ---...--------. .----- ----------- 6


EXPERIMENTS ..................



Soil Applications ......


Experiment 1 -...


Experiment 2 .....


Experiment 3 .....-....



Foliage Applications ....


Experiment 1 ..-......


Experiment 2 .......


Experiment 3 .......


Experiment 4 .........



VARIETAL SUSCEPTIBILITY .


. -.... -- ---- ... ..... 12


........ ......- ....-......--- -. ------- 14


................. ...... .-- ....--- ..--- 15


...................- ------..................---------- 16


.----- 17


...................---.......- 19


....... --.. --..--- 19


.....-.. ----..... 20


-.....- -------... 20


.........-.. -------. 21


... ... .......... .... -...- ..------- .. 22


FOLIAGE ANALYSIS .......--....-------- ---------


---...... ----..... ..-....... 23


SOILS


EFFECTS OF OTHER ELEMENTS ..............--


Copper-Nitrogen Balance ............-.............


Copper-Phosphorus Relationships in Soils


RECOMMENDATIONS FOR CONTROL ..--......-....-


-.. 24


- .......... .......-- .. ... 25


.....-...... -----.-.. .-- --- .. 25


..~......................-- .. 26


----......... ---.-------.. ... 27


SUMMARY .---..----.


LITERATURE CITED .......--.........--..---..-------- ----------------------- 31










COPPER DEFICIENCY OF TUNG

IN FLORIDA

By
R. D. DICKEY, MATTHEW DROSDOFF AND JOSEPH HAMILTON1

Introduction
A physiological disorder of tung (Aleurites fordi Hemsl.) in
Florida, distinct in appearance from zinc deficiency (bronzing),
manganese deficiency (frenching) and iron deficiency, previous-
ly described (3, 12, 14)2, was observed during the late summer of
1941 on a few trees in a large seven-year-old tung orchard near
Morriston, Florida. Symptoms recurred in this orchard in 1942
and it was estimated that over 100 acres of trees were showing
the disorder in varying degree. In the late spring and summer
of 1942 several hundred acres of young trees were severely af-
fected in a newly planted tung orchard near Alachua, Florida.
Experiments conducted in this orchard at that time produced
evidence that the disorder was due to a copper deficiency (4).
Several orchards in the vicinity of Gainesville, Florida, were
observed to have some affected trees. It is interesting to note,
however, that in two of the largest tung orchards near Gaines-
ville the symptoms were not observed. In these orchards copper
sulfate had been applied regularly in the fertilizer mixture.
Apparently copper deficiency of tung is of recent occurrence in
Florida, as examinations of the commercial tung orchards have
been made from time to time, yet it was not observed until 1941.
Reuther and Dickey (14) and Dickey (2) report a similar situa-
tion in regard to the appearance of manganese and iron deficien-
cies of tung.
Copper deficiency of tung has not yet been reported from the
other states in which tung is grown commercially and it has
been observed thus far in only the northern peninsular area of
Florida. However, the history of several other micro-element
deficiencies on fruit and nut trees indicates that as time passes
they become progressively more widespread and severe.

1 Assistant Horticulturist, Fla. Agr. Exp. Sta., and Soil Technologist and
formerly Assistant Pomologist, respectively, U. S. Field Laboratory for
Tung Investigations, Gainesville, Florida.
2 Italic figures in parentheses refer to "Literature Cited" in the back
of this bulletin.








Florida Agricultural Experiment Station


That copper is essential in the nutrition of higher plants is
now generally accepted. No attempt will be made here to re-
view the extensive literature dealing with the occurrence of
copper deficiency in plants under field conditions, as that already
has been done adequately (1, 13, 15).
Literature on copper deficiency in many plants in the United
States and other countries attests the importance of nutritional
troubles due to this cause. In Florida, particularly, severe cop-
per deficiency of citrus was once prevalent. Also, without the
application of copper the organic soils of the Everglades and
other similar areas are not productive. This clearly indicates
the importance of copper in some phases of Florida agriculture.
The primary purpose of this bulletin is to describe copper de-
ficiency in tung trees and give recommendations for its control.

Symptoms
The characteristic foliage symptoms of copper deficiency in
tung are chlorosis, dwarfing and "cupping" of the leaves, a
marginal burn of the terminal leaves and premature abscission
of some of the leaves. Shoot symptoms are reduced growth,
dead buds and dieback of shoots on affected trees.
The symptom most characteristic of the deficiency is a "cup-
ping" of the terminal leaves produced by the upward curling of
their margins (Figs. 1, 2, 6). In mild stages affected leaves
may show very little dwarfing, but as the disorder increases in
severity the terminal leaves especially are greatly reduced in
size and the leaf surface is rugose in appearance (Figs. 1, 2, 8).
Young affected leaves as they expand develop a marginal burn
and often necrotic areas appear in the interveinal areas. As af-
fected leaves grow the amount of dead tissue increases and much
of the dead marginal and interveinal tissue may eventually fall
away, leaving irregular ragged margins and holes in the leaves
(Figs. 1, 3, 7, 8).
Chlorosis is another very characteristic symptom which devel-
ops in conjunction with cupping and marginal burn. The chloro-
sis is evident over the entire surface of the leaf and develops as
the leaf grows. Affected young leaves are a lighter green in
color than normal leaves, but the tissue immediately surrounding
the midrib and main and secondary veins is slightly darker green
than the interveinal areas. As affected leaves mature this con-
trast is increased as the areas between the veins become pale






Copper Deficiency of Tung in Florida


yellow, while the tissue immediately surrounding the midrib and
secondary veins is green (Figs. 1, 3).


ti, NIt


IJ0


Fig. 2.-One-year-old tung tree showing acute symptoms of copper de-
ficiency (extreme dwarfing of terminal leaves, cupping, marginal burn and
defoliation). Tree planted February 1942, photograph taken August 5,
1942.


41h


II r


-11,
'"*a


~CJ~
1






Florida Agricultural Experiment Station


ri- -
II


4i


Fig. 3.-Shoot from tung tree showing acute symptoms of copper de-
ficiency-cupping, chlorosis, defoliation, ragged leaves and dead terminal
bud.

A considerable amount of premature leaf-fall takes place, par-
ticularly if the leaves show a large amount of dead tissue. Trees
evidencing acute symptoms may be defoliated severely by early
June (Figs. 2, 3, 8, 9). This is especially true of younger trees.
Mature trees may not show much defoliation before July or
August.
When the deficiency is severe there is usually a definite reduc-
tion in shoot growth, evidenced by a decided shortening of the








Copper Deficiency of Tung in Florida


Fig. 4.-Tung leaves showing typical steps in the development of man-
ganese deficiency symptoms. From left to right: 1, immature leaf show-
ing first visible evidence of chlorosis; 2 and 3, progressive stages in the
development of chlorosis; 4 and 5, development of necrotic spots in chlorotic
areas of more mature leaves.


Fig. 5.-Tung shoot showing typical steps in the development of man-
ganese deficiency symptoms-chlorosis and necrosis.

internodes in comparison with that of unaffected trees (Figs. 2,
8, 9, 10).
With the defoliation of the terminal part of the shoot the
growing point is affected and often dies when new shoot growth







Florida Agricultural Experiment Station


from lateral buds is stimulated (Fig. 3). Shoots so affected
may die back to varying degrees. On older trees the dieback is
quite noticeable as the dead shoots protrude beyond the general
outline of the tree (Fig. 9).
Trees showing symptoms of copper deficiency are exceedingly
subject to injury by cold weather and killing of terminal buds
and shoots may take place. The potential yield of a bearing tree
is reduced in direct proportion to the number of terminal buds
killed.
The oil content of fruits from trees showing copper deficiency
was found to be approximately 3 percentage units less and the
fruits were smaller in size than those from normal trees (7).
Unpublished data showed that in certain orchards the yield of
fruit from copper-deficient trees was reduced to as much as half
that of normal trees.
In most cases the initial growth in the spring is normal, but
as the season progresses the terminal leaves soon show symptoms
which increase in severity. Some trees may show symptoms
early in the season and later become healthy, while others may
make normal growth during most of the year and develop symp-
toms toward the end of the growing season.
In the area where copper deficiency symptoms appear, zinc de-
ficiency also is prevalent and symptoms of both deficiencies
occasionally occur on the same tree. When this happens each
appears on the leaves of separate shoots and commonly all the
affected shoots on any branch will show symptoms of the same
deficiency. However, leaves showing both zinc and copper de-
ficiencies are occasionally seen on the same shoot and a partial
masking of typical symptoms of each deficiency results. Man-
ganese deficiency symptoms are common in the general area
where copper and zinc deficiencies are present and may further
complicate the symptom diagnosis.
Chlorosis is a symptom exhibited by the three disorders, but
the contrast between the chlorotic tissue and green veins of af-
fected leaves is more noticeable with copper and manganese de-
ficiencies than with zinc deficiency. Zinc deficiency, character-
ized by malformation of the leaves in which one side of the leaf
blade is smaller than the other, can be readily distinguished from
copper deficiency. Manganese deficiency may be distinguished
from copper deficiency by the absence of cupping and extreme
dwarfing of terminal leaves and the marginal burn that develops
as the leaves of copper-deficient trees emerge from the growing






Copper Deficiency of Tung in Florida


point. These differences are illustrated in Figures 1, 2, 3, 4,
5,6.
The three disorders can be differentiated also by the type of
necrotic areas developed on the leaves. Manganese deficiency
exhibits dark-brown spots within the chlorotic areas and indivi-
dual spots are small (Figs. 4, 5). Zinc-deficient leaves show


Fig. 6.-Shoots from tung trees showing typical foliage symptoms of:
Left, copper deficiency (small terminal leaves, cupping and marginal burn);
right, zinc deficiency (malformation and wavy margins).


VtO

IL^hf
V7 ql


Fig. 7.-Typical treated and copper-deficient tung shoots. Left, check
(untreated) tree; right, from tree which received 1/6 ounce of copper sul-
fate in % pint of water. Treated, July 8, 1942, photographed August 5,
1942.


~,A4







Florida Agricultural Experiment Station


relatively large dead areas scattered at random over the leaf
surface, while in copper deficiency immature leaves develop a
marginal burn (Figs. 1, 2, 6).
Copper and manganese deficiency symptoms usually appear in
the early part of the growing season, while zinc deficiency symp-
toms are rarely apparent much before early summer and usually
do not become acute until late summer.

Experiments
The experimental work herein reported was conducted from
1942 to 1947 in two commercial tung orchards in Florida, one
near Morriston, in Levy County, the other near Alachua, in
Alachua County, and in an experimental planting on the Experi-
ment Station farm at Gainesville.
Treatments consisted of both soil and spray applications of
copper sulfate.
At the time of treatment all trees used in these experiments
were examined and a rating was made of the relative severity of
the copper deficiency symptoms on each tree. Additional ex-




















Fig. 8.-A, One-year-old tung tree showing acute symptoms of copper
deficiency (cupping, defoliation and ragged leaves). B, One-year-old tung
tree which had symptoms similar to those of (A) at time of treatment on
July 8, 1942 with 1/6 ounce of copper sulfate in /4 pint of water applied
to soil at base of tree. The copper treatment has effected complete control
of copper deficiency, while (A) continues to show acute symptoms. Photo-
graphs taken August 5, 1942.







Copper Deficiency of Tung in Florida


aminations and ratings were made during each experiment.
Copper deficiency was scored as follows: 0 indicated no symp-
toms, 25 indicated slight symptoms, and 100 very severe copper
deficiency with all the foliage affected, while 50 and 75 indi-
cated intermediate conditions. The scores of the individual
trees were then added and the sum divided by the number of
trees in a treatment. In interpreting these data it can be seen
that the trees in a treatment having an average copper deficien-
cy score of 100 would be very severely affected, while those hav-


-. '.




I-
~A
vi I;


law

Z;


. -.' -


Fig. 9.-Three-year-old tung tree showing acute symptoms of copper
deficiency. This tree was sprayed with an 8-8-100 copper-lime mixture on
June 5, 1945. Photograph taken at the time of treatment. (Cf. Fig. 10.)







Florida Agricultural Experiment Station


ing a score of 0 would show no symptoms. In scoring the trees
after treatment only the leaves on the new growth were con-
sidered because the leaves affected before treatment are usually
beyond recovery.

Soil Applications

In preliminary trials made in July 1942 (4), 1/6 ounce of cop-
per sulfate dissolved in 3/ pint of water and applied to the soil
at the base of the tree in one week effected recovery of one-year-
old trees showing severe copper deficincy (Figs. 7, 8). On the
basis of these results, the owners of the orchard treated several
thousand affected young trees similarly in the latter part of


U I


a


J.


Fig. 10.-Same tree shown in Fig. 9, but photograph taken Sept. 14,
1945. Sprayed with an 8-8-100 copper-lime mixture. New growth made
after spray was applied is normal. (Cf. Fig. 9.)


.AAt









Copper Deficiency of Tung in Florida


July. Practically all of the trees recovered and were growing
normally by the end of the growing season.
Experiment 1.-Following this lead, an experiment was set
up in a copper-deficient area in an eight-year-old tung orchard
near Morriston on Lakeland fine sand. It was estimated that, in
this area, over 100 acres of trees were showing the symptoms
in varying degree. The trees for the tests were selected pri-
marily for uniformity of size and degree of copper deficiency
symptoms.
The initial treatments were made July 22, 1942. There were
eight treatments with eight replications using single tree plots
(Table 1). Copper sulfate was applied as the dry salt at the
rates of 1/2, 1, 2 and 4 pounds per tree, broadcast under the
spread of the tree, and in solution at the rate per tree of 1 ounce
in 1 pint of water, 1/2 pound in 1 gallon of water and 1 pound
in 2 gallons of water. There was an untreated check. The 1/2,
1 and 2-pound applications of copper sulfate as the dry salt were
repeated April 12, 1943. The solution was poured into a hole
made with a shovel about 1 foot from the tree trunk.

TABLE 1.-Effect of Soil Applications of Copper Sulfate as the Dry Salt,
and in Solution, in Correcting Copper Deficiency (Morriston, Florida,
1942-43).


Treatment

None (check)
/2 pound copper sul-
fate broadcast
1 pound copper sul-
fate broadcast
2 pounds copper sul-
fate broadcast**
4 pounds copper sul-
fate broadcast***
1 ounce copper sul-
fate in 1 pint of
water
pound copper sul-
fate in 1 gallon of
water
1 pound copper sul-
fate in 2 gallons
of water***


Date A


July 22,
l i 2


Average Score of Copper Deficiency
Symptoms on Different Dates*
applied July 22, Sept. 9, May 27, Oct. 23,
1942 1942 1943 1943
90.6 90.6 71.9 46.9
1942, and 90.6 90.6 49.4 0.0


Apr 1 M43
July 22, 1942, and
April 12, 1943
July 22, 1942, and
April 12, 1943
July 22, 1942

July 22, 1942

July 22, 1942

July 22, 1942


84.4 71.9 20.0 0.0

93.8 71.9 16.8 0.0

78.1 40.6 25.0 10.6

87.5 84.4 50.6 13.8


93.8 75.0 28.8


96.9 56.3 25.6 11.3


*On a scale from 0, which indicates no copper deficiency symptoms, to
100, which indicates very severe symptoms on the foliage. After treat-
ment only the leaves on the new growth were scored because leaves
affected before treatment are usually beyond recovery.
**Produced a moderate amount of burning and defoliation.
***Severely burned the foliage and produced considerable defoliation.







Florida Agricultural Experiment Station


The data obtained (Table 1) show that by the end of 1943 cop-
per deficiency symptoms were greatly reduced by the appli-
cation of copper sulfate. Analysis of the data shows that re-
sponses to all treatments receiving copper have high statistical
significance. However, the four-pound application of the dry
salt and the 1 pound in 2 gallons of water burned the foliage
severely and produced considerable defoliation. The 2-pound ap-
plication of the dry salt produced a moderate amount of burning
and defoliation. The treatments of 1/2 pound of copper sulfate
in 1 gallon of water and 1 pound applied as the dry salt appear to
be safe applications for eight-year-old trees.
Experiment 2.-This experiment was set up at the same time
as Experiment 1. Its object was to determine the effect of the
volume of the water in which the copper sulfate was dissolved,
in correcting copper deficiency symptoms. The trees were in an
adjoining area in the same orchard and on the same soil type,
and were selected in so far as possible for uniformity in size and
copper deficiency symptoms. The solutions were applied as
previously described. Four treatments were made July 23, 1942,
in six replications of one-tree plots, as follows: 1/ pound of cop-
per sulfate in 1 quart, 1 and 2 gallons of water, and an untreated
check (Table 2).
The data obtained (Table 2) show that copper deficiency was
materially reduced by the end of 1943 by the application of cop-
per sulfate and that there was no advantage in using the larger
amounts of water. Analysis of the data shows that differences

TABLE 2.-Soil Treatments Showing the Effect of Volume of the Solution
in which Copper Sulfate is Dissolved in Correcting Copper Deficiency
(Morriston, Florida, 1942-43).

Average Score of Copper Deficiency
Treatments Applied on July 23, 1942 Symptoms on Different Dates*
July 23, Sept. 9, May 27, Oct. 23,
1942 1942 1943 1943

None (check) 87.5 75.0 65.8 55.8
% pound copper sulfate
in 1 quart of water 100.0 41.7 12.5 1.7
1 pound copper sulfate
in 1 gallon of water 87.5 62.5 30.0 8.3
% pound copper sulfate
in 2 gallons of water 79.2 70.8 21.7 4.2

*On a scale from 0, which indicates no copper deficiency symptoms, to
100, which indicates very severe symptoms on the foliage. After treat-
ment only the leaves on the new growth were scored because leaves
affected before treatment are usually beyond recovery.








Copper Deficiency of Tung in Florida 17

between the check and all treatments receiving copper have high
statistical significance.
Experiment 3.-A factorial experiment to test the effects of
two levels of five elements-copper, zinc, manganese, calcium and
magnesium-applied in the spring was initiated in 1943 in a
newly planted tung orchard near Alachua. The area used in
this experiment is predominantly Arredondo loamy fine sand.
There were 32 treatments replicated three times, making a total
of 96 plots, each having six record trees consisting of three
budded trees of Isabel variety and three trees of an F-9 seed-
ling progeny. Each plot was surrounded with guard trees. Of
the five elements applied, only copper is considered in this dis-
cussion. Forty-eight plots received the low level and 48 re-
ceived the high level of copper. The trees in the experiment,
which ran for three years, were given commercial fertilizer by
the grower as follows: 1 pound of 6-4-8 in 1943, 1/2 pound of 6-4-8
and 1 pound of 8-0-12 in 1944; 3 pounds of 8-0-8 in 1945. Cop-
per sulfate was applied as the dry salt, 1 and 3 ounces per tree for
the low and high levels, respectively, in 1943, broadcast under
the spread of the branches.

TABLE 3.-Effect of Soil Applications of 2 Levels of Copper Sulfate in
Reducing Copper Deficiency on Budded Trees of the Variety Isabel and on
F-9 Seedlings during 3 Seasons (Alachua, Florida, 1943-45).
Average Score of
Level of Date of Percentage of Copper
Copper Scorig Number of Trees Trees Showing Deficie
Applied* corg Scored Symptoms fyeptoms on
Different
Dates**
Isabel Seedling Isabel Seedling Isabel Seedling
F-9 F-9 F-9
Low 144 131 68.8 12.2 44.8 3.6
July 16, 1943
High 140 125 42.8 2.4 23.6 0.8
Low 141 118 27.6 16.9 12.2 7.0
July 13, 1944
High 137 114 16.8 1.8 7.3 0.7
Low 133 118 21.8 10.2 5.1 2.6
May 21, 1945
High 133 117 12.0 4.3 2.3 0.4

*Low level; %, 1 and 1 ounce, and high level, 3, 6 and 4 ounces, respec-
tively, of copper sulfate per tree in 1943, 1944 and 1945.
**On a scale from 0, which indicates no copper deficiency symptoms, to
100, which indicates very severe symptoms on the foliage. After treat-
ment only the leaves on the new growth were scored because leaves
affected before treatment are usually beyond recovery.

3 Formerly designated as L-2.







Florida Agricultural Experiment Station


Analysis of the data (Table 3) shows that in 1943 even the
high application of copper sulfate did not effect complete control
of copper deficiency, although it produced a highly significant
reduction in copper deficiency symptoms as compared with the
low level. The high level of copper burned the foliage of some
of the trees. There was a highly significant difference in the
copper deficiency score between the trees of variety Isabel and
the seedling trees of F-9. The copper treatment was more effec-
tive with the F-9 seedling trees than on those of the Isabel
variety.
In 1944 the low and high levels of copper were 1 and 6 ounces,
respectively, of copper sulfate split into two applications of 1/2
and 3 ounces per tree; the first was applied in May and the sec-
ond in August.
The high level of copper produced a significant reduction in
copper deficiency symptoms as compared with the low copper and
there was a significant difference in copper deficiency symptoms
between the budded and seedling trees. Three ounces per tree of
copper sulfate in each of two applications did not burn the foliage
in 1944, probably because of the increased age of the trees and
differences in rainfall conditions following the applications. An
examination of the data shows that both the number of trees
showing symptoms and the degree of copper deficiency were con-
siderably less in this planting in 1944 than in 1943 (Table 3).
In 1945 the low and high levels of copper were 1 and 4 ounces,
respectively, of copper sulfate per tree. This season there was
no significant difference between treatments and the difference
between budded and seedling trees had been largely lost. There
was a marked reduction in copper deficiency symptoms, both as
to the number of trees affected and the degree of severity (Table
3). This may have been due to the cumulative effect of copper
applications over the three-year period. Perhaps the larger root
systems of the trees as they get older is another factor in reduc-
ing the incidence of copper deficiency in this location.
In 1946 and 1947 the owner applied approximately 3 ounces
of copper sulfate per tree to all trees in the experiment, in addi-
tion to 5 pounds of 6-6-6 fertilizer. No record was taken in 1946
of copper deficiency symptoms. However, the experimental area
was examined three times during the growing season and some
trees were observed that showed symptoms of copper deficiency.
All trees in the planting were carefully scored July 28, 1947, and
none showed copper deficiency symptoms.







Copper Deficiency of Tung in Florida


Foliage Applications

In 1942 Drosdoff and Dickey (4) sprayed one-year-old tung
trees showing copper deficiency with 1 and 2 percent copper sul-
fate solutions containing an equal amount of lime. In less than
one month new growth showing no symptoms of copper deficiency
appeared on the sprayed trees, while the untreated trees showed
severe symptoms. Further experiments on spraying tung trees
for the control of copper deficiency are given below.
Experiment 1.-This experiment was conducted in 1943 in a
block of one-year-old trees on the Experiment Station farm near
Gainesville. The soil on which the trees were planted is Arre-
dondo fine sandy loam. Many trees in this planting showed
severe copper deficiency symptoms by early July. As zinc defici-
ency was observed on some trees in the planting, it was decided
to include zinc sulfate in the spray mixture. Spray treatments
were made July 8, as follows: (1) Copper-zinc-lime mixture of
2 pounds copper sulfate, 4 pounds zinc sulfate, and 2 pounds
hydrated lime in 100 gallons of water; (2) 4 pounds of copper
sulfate, 4 pounds of zinc sulfate, and 4 pounds of hydrated lime
in 100 gallons of water; (3) untreated check. The data obtained
(Table 4) show that both concentrations of the spray mixture
effected an immediate and drastic reduction in copper deficiency
symptoms. However, after about two months, symptoms re-
curred and the number of trees affected and the degree of sev-
erity were greater on the trees sprayed with 2 pounds of copper
sulfate in the mixture than on those that were sprayed with the
mixture containing 4 pounds per 100 gallons. Zinc and copper

TABLE 4.-Effect of Spray Applications of Copper-Zinc-Lime Mixture in
Correcting Copper Deficiency of Tung Trees (Gainesville, Florida, 1943).
Number of Average Score of Copper Deficiency
Treatments Applied on Trees Symptoms on Different Dates*
July 6, 1943 Treated July 6, 1943 July 26, 1943 Sept. 10, 1943
None (check) 8 65.6 56.3 78.1
Copper-Zinc-Lime
(2-4-2-100) 19 55.3 1.3t 15.8:
Copper-Zinc-Lime
(4-4-4-100) 17 51.5 0.0 4.4t

*On a scale from 0, which indicates no copper deficiency symptoms, to
100, which indicates very severe symptoms on the foliage. After treat-
ment only the leaves on the new growth were scored because leaves
affected before treatment are usually beyond recovery.
tOne tree showed symptoms.
$Seven trees showed symptoms.







Florida Agricultural Experiment Station


sulfates are compatible and the 4 pounds of zinc sulfate satis-
factorily controlled the zinc deficiency that had been present on
some of the trees.
Experiment 2.-This experiment was conducted in a commer-
cial tung orchard near Alachua, in a block of three-year-old trees.
The soil upon which these trees were growing was predominant-
ly an Arredondo fine sandy loam. The trees selected for the
experiment were showing severe copper deficiency symptoms
at time of treatment July 30, 1943. The treatments applied
were as follows: (1) a 1-1-100 copper-lime mixture; (2) a 1-1-
200 copper-lime mixture; (3) a 1-100 copper sulfate solution;
(4) a 1-200 copper sulfate solution, and (5) an untreated check.
The data obtained (Table 5) show that after two weeks follow-
ing the spray applications of both concentrations of copper-lime
mixtures and copper solutions a rapid reduction in copper defici-
ency symptoms occurred. The foliage of all trees sprayed with
the solution of 1 pound of copper sulfate in 100 gallons of water
was burned in slight to moderate amounts. This indicates that
hydrated lime must be used in the mixture because stronger con-
centrations of copper sulfate are now recommended for the con-
trol of copper deficiency. An examination of the experimental
trees two months after treatment disclosed that copper defici-
ency symptoms had recurred generally over the treated trees.
Experiment 3.-The tree:, used in this experiment were planted
in the guard rows of the experimental planting previously dis-
cussed as Experiment 3 under "Soil Applications" and were in

TABLE 5.-Effect of Spray Applications of Copper-Lime Mixtures and
Copper Solutions in Correcting Copper Deficiency of Tung Trees (Alachua,
Florida, 1943).
Number of Average Score of Copper Deficiency
Treatments Applied Trees Symptoms on Different Dates*
On July 30, 1943 Treated July 30, 1943 August 13, 1943
None (check) 12 50.0 35.4
Copper-Lime Mixture
(1-1-100) 10 62.5 2.5
Copper Solution
(1-100)** 10 65.0 0.0
Copper-Lime Mixture
(1-1-200) 7 53.6 0.0
Copper Solution
(1-200) 6 54.2 4.2
*On a scale from 0, which indicates no copper deficiency symptoms, to
100, which indicates very severe symptoms on the foliage. After treat-
ment only the leaves on the new growth were scored because leaves
affected before treatment are usually beyond recovery.
**Foliage of all trees showed copper burn in slight to moderate amounts.







Copper Deficiency of Tung in Florida


their third year in the orchard on June 6, 1945, when treatments
were made. Though they had received approximately 41/2 ounces
per tree of copper sulfate applied as a dry salt to the soil while in
the orchard, a number of trees showed copper deficiency symp-
toms. The trees used in this experiment were selected primarily
for uniformity of size and degree of copper deficiency symptoms.
Four spray treatments of copper-lime mixtures and a check
all replicated 15 times in single-tree plots were set up as follows:
(1) 1-1-100 applied once; (2) 1-1-100 applied twice; (3) 8-8-100
applied once; (4) 8-8-100 applied twice; (5) untreated check.
Because of poor shoot growth in this planting during the sum-
mer of 1945, it was decided to omit the second applications after
scoring the trees in the experiment on July 5.
The data obtained (Table 6) show that both concentrations
of copper-lime mixtures produced a rapid and complete control
of copper deficiency symptoms (Figs. 9, 10). However, symp-
toms had recurred in the 1-1-100 copper-lime treatments ap-
proximately 10 weeks after spraying. The low concentrations
of copper sulfate supplied enough copper to correct the copper
deficiency rapidly, but the effects did not last through the grow-
ing season. Similar results were obtained in Experiments 1 and
2 (Tables 4, 5). It is of interest to note the similarity of re-
sults obtained from the two duplicate treatments.
Experiment 4.-The trees used in this experiment were plant-
ed in the guard rows previously mentioned in Experiment 3 and
were four years old in 1946 when treatments were made. Though
they had received approximately six ounces of copper sulfate ap-
plied to the soil as the dry salt, during the four years, many trees

TABLE 6.-Effect of Spray Application of Copper-Lime Mixture in Cor-
recting Copper Deficiency of Tung (Alachua, Florida, 1945).
Average Score of Copper Deficiency Symptoms
Treatments Applied On Different Dates*
June 6, 1945 June 6, 1945 July 5, 1945 August 23, 1945
None (check) 83.3 78.8 87.7
Copper-lime mixture
(1-1-100) 83.3 0.0 14.3
Copper-lime mixture
(1-1-100) 81.6 0.0 10.7
Copper-lime mixture
(8-8-100) 83.3 0.0 0.0
Copper-lime mixture
(8-8-100) 81.6 0.0 0.0
*On a scale from 0, which indicates no copper deficiency symptoms, to
100, which indicates very severe symptoms on the foliage. After treat-
ment only the leaves on the new growth were scored because leaves
affected before treatment are usually beyond recovery.







Florida Agricultural Experiment Station


evidenced copper deficiency symptoms. The trees for the test
were selected primarily for uniformity of size and degree of cop-
per deficiency symptoms. Three treatments were used in single-
tree plots with 13 replications as follows: (1) 8-8-100 copper-
lime mixture, applied once (May 3); (2) 8-8-100 copper-lime mix-
ture, applied twice (May 3 and July 17); (3) untreated check.
The data obtained (Table 7) show that a spray application of
8-8-100 copper-lime mixture effected a rapid and complete con-
trol of copper deficiency. Also, one application of the spray
was as effective as two applications in controlling the deficiency
for the duration of the growing season. These results are partic-
ularly interesting because the trees used in this experiment
made very vigorous growth throughout the 1946 growing sea-
son, yet one application of the concentration used was sufficient
for complete control. Similar results were obtained in Experi-
ment 3 (Table 6).

TABLE 7.-Effect of Spray Applications of Copper-Lime Mixture in Cor-
recting Copper Deficiency of Tung Trees (Alachua, Florida, 1946).
Average Score of Copper Deficiency Symptoms
Treatment On Different Dates*
May 9, 1946 June 5, 1946 Oct. 10, 1946
None (check) 63.5 61.5 51.9
Copper-lime mixture
(8-8-100 Applied
May 3, 1946) 63.5 0.0 0.0
Copper-lime mixture
(8-8-100 Applied
May 3 and July 17,
1946) 61.5 0.0 0.0
*On a scale from 0, which indicates no copper deficiency symptoms, to
100, which indicates very severe symptoms on the foliage. After treat-
ment only the leaves on the new growth were scored because leaves
affected before treatment are usually beyond recovery.

Varietal Susceptibility
Differences in tung varieties in susceptibility to copper defici-
ency were reported by Gilbert et al (6) and Hamilton and Gilbert
(8). In working with the varieties L-14, A-12, and F-193 they
found that F-193 was more susceptible to copper deficiency under
the conditions of their experiment than the other two varieties.
An examination of the data in Table 3 shows that the trees
of the Isabel variety were more susceptible to copper deficiency
than were the F-9 seedling trees under the conditions of this
experiment.
Six budded varieties and seven seedling tung progenies were
planted in five-tree plots replicated four times in the guard rows








Copper Deficiency of Tung in Florida


of the experimental planting previously discussed as Experiment
3 under "Soil Applications." On May 23, 1945, when the trees
were three years old, copper deficiency records were taken. Dur-
ing the three years all trees had received the same cultivation
and fertilization, which included the application of approximate-
ly 41/2 ounces of copper sulfate to the soil as the dry salt. How-
ever, at the time of scoring, symptoms of the deficiency were
general over the experimental area.
An examination of the data (Table 8) shows that certain
varieties and seedling progenies are much less susceptible to
copper deficiency than others under the conditions of this ex-
periment. It is of interest to note that there is no significant
difference between the copper deficiency score of the budded
varieties and trees grown from open-pollinated seed of the same
variety where both appear in the planting: For example, G-37B
and G-37S, F-546B and F-546S, F-566B and F-566S.

TABLE 8.-Average Score of Copper-Deficiency Symptoms Shown by 6
Different Budded Varieties and 7 Different Seedling Progenies.
Copper-Deficiency Symptoms
Variety or Seedling Progeny* (Score, May 23, 1945)**
G-37B 11.0
F-9S 12.0
G-37S 18.8
F-546S 20.0
F-546B 20.7
F-542S 25.0
F-566S 25.6
G-46S 33.7
F-542B 34.4
G-46B 39.7
F-566B 49.7
M-1B 50.3
M-1S 60.8
Least significant difference at 0.05 28.7
Least significant difference at 0.01 38.5
*The budded varieties are indicated by the letter B after the variety num-
ber and the seedling progenies by the letter S.
**On a scale from 0, which indicates no copper deficiency symptoms, to
100, which indicates very severe symptoms on the foliage.

Foliage Analysis
Though copper is essential for the growth of tung trees, the
amount present in the trees as indicated by the analysis of the
leaves is exceedingly small, as is true for most if not all plants.
It has been found (4) that midshoot leaves from untreated one-
year-old copper-deficient trees contain about 3 p. p. m. of copper,
while leaves from the same age trees in the same area which had







Florida Agricultural Experiment Station


recovered from copper deficiency after a soil treatment contained
about 4 p. p. m. of copper. Apparently only minute amounts
of copper are necessary to effect recovery from copper deficiency.
This agrees with the experience of Piper (13) who, working with
small grains, found that increased absorption of copper by plants
that recovered as a result of soil applications was surprisingly
small.
Unpublished data obtained at the U. S. Field Laboratory for
Tung Investigations at Gainesville would indicate that midshoot
leaves collected in late summer from one- and two-year-old cop-
per deficient trees contain about 3 p. p. m. of copper or less,
while leaves from normal appearing one-year-old trees contain
over 4 p. p. m. of copper.
Data obtained on the analysis of leaves collected in the sum-
mer from bearing trees are similar to those obtained from young-
er trees. At one location (4) there was an average of 3.6 p. p.
m. of copper in leaves from affected trees and 5.7 p. p. m. in
leaves from normal trees in an adjacent healthy block. Leaves
from normal trees in the affected area contained 4.1 p. p. m.
of copper. Analyses of leaves (7) collected from one location
periodically during the season showed that the copper content
increased during the season. Leaves from copper-deficient
trees contained 2.8 p. p. m. of copper on June 28, while leaves
from normal trees contained 6.1 p. p. m. On August 15 the leaves
from the deficient and normal trees contained 4.8 and 8.0 p. p. m.,
respectively, and on October 23 the contents were 9.6 and 16.1
p. p. m., respectively. This increase was in accord with obser-
vations in the field that the leaf-deficiency symptoms in the ex-
periment diminished on the new growth toward the end of the
growing season. It may be that in other areas or in other sea-
sons when copper deficiency symptoms have been observed to in-
crease during the season the copper-leaf content would show
the opposite trend.
Samples of midshoot leaves collected in midsummer from bear-
ing trees from a number of tung orchards in the State which
have never shown any copper-deficiency symptoms seldom con-
tain less than 6 p. p. m. of copper and usually at least 7 or 8.

Soils
The soils on which copper deficiency of tung trees has been
found are predominantly the sands and loamy fine sands of







Copper Deficiency of Tung in Florida


peninsular Florida and include the following types: Ft. Meade
fine sand and loamy fine sand, Arredondo fine sand and loamy
fine sand, Gainesville fine sand and loamy fine sand, Blanton
fine sand and Lakeland fine sand. Harris (9) has recently re-
ported copper deficiency of oats on Arredondo loamy fine sand
in the Gainesville area. To date no copper deficiency of tung
trees has been observed or reported on the finer textured soils
of northern and northwestern Florida, such as the Red Bay fine
sandy loam and related or associated soil types.
In general all of the soils on which copper deficiency has been
found are highly leached soils with a low fertility level (5).
They are low in clay and organic matter content and therefore
low in exchangeable bases. Zinc, magnesium and other mineral
element deficiencies besides copper frequently occur in tung or-
chards on these soils, unless corrected by proper fertilizer
treatment.
Not all tung orchards on these soil types have shown copper-
deficiency symptoms. Many factors are involved in the incid-
ence of the symptoms and probably the most important are the
management and fertilizer practices used, the kind of trees plant-
ed and the natural variation in fertility within the soil type.

Effects of Other Elements
There is a growing recognition in recent years of the import-
ance of nutrient element balance, and recently Shear, Crane and
Myers (17) and Shear and Crane (16) have given added empha-
sis to this concept. There is little doubt that the absorption and
utilization of copper by the plant is profoundly affected by the
concentration of other elements present, both in the soil and in
the plant. The copper-nitrogen balance is an outstanding ex-
ample.
Copper-Nitrogen Balance
Gilbert et al (6) and Hamilton and Gilbert (8) found that the
higher the level of nitrogen applied the more severe were the
copper deficiency symptoms. Thus, on soil low in copper the
application of nitrogen to the trees accentuated the symptoms
of copper deficiency. They conducted an experiment in 1943
near Alachua, Florida, in which four levels of copper sulfate,
ranging from none to 2 ounces per tree, were supplied to one-
year-old seedling trees. At each level of copper, nitrogen was
applied at four levels, namely, 0.01, 0.03, 0.09 and 0.18 pound of







Florida Agricultural Experiment Station


elemental nitrogen per tree, half as sodium nitrate and half as
ammonium sulfate.
When no copper was applied as the nitrogen was increased, the
severity of copper deficiency symptoms increased and the high-
est level of nitrogen produced the most severe symptoms, while
no or very slight symptoms developed from the low nitrogen ap-
plications. The highest level of copper sulfate applied was not
sufficient to prevent the development of the deficiency at the
extremely high nitrogen levels, though symptoms of excess cop-
per appeared when the high copper levels were first applied.
From a commercial standpoint, however, the highest level of
copper applied produced adequate control of copper deficiency at
all nitrogen levels. They consider this a case of balance between
the nitrogen and copper within the plant tissue. Finally, they
point out that for soil areas low in copper, it is of utmost import-
ance to supply a proper balance of copper and nitrogen in the fer-
tilizer mixture and recommend that for one-year-old transplanted
trees this balance be at least 1 ounce of copper sulfate to 0.04
pound of elemental nitrogen and a similar ratio for older trees.
Copper and nitrogen supplied in the proper balance, as previ-
ously suggested, do not always insure that adequate commercial
control will be obtained in all locations from soil applications.
Experiment 3 under "Soil Applications" was initiated in 1943
on the same soil type in another part of the orchard in which
Hamilton and Gilbert (8) conducted their experiment. One-half
of the trees received 3 ounces of copper sulfate each and fer-
tilizer which contained 0.05 pound of elemental nitrogen per tree.
Though copper was supplied considerably in excess of the sug-
gested copper-nitrogen ratio for one-year-old trees, satisfactory
control of copper deficiency was not obtained with the more sus-
ceptible Isabel variety in this location during that season.

Copper-Phosphorus Relationships in Soils
There has been some concern about the effect of phosphate in
the soil or in applied superphosphates on the availability of cop-
per. Working with soils in the citrus area, Jamison (10) found
that only in the presence of great excesses of soil phosphates far
beyond ordinary practical limits is the solubility of copper or zinc
affected in most peninsular Florida soils. This would indicate
that, under ordinary commercial management and fertilizer prac-
tices, the availability of copper to trees on sandy soils is not ad-
versely affected by the phosphate present in the soil.








Copper Deficiency of Tung in Florida


Similar results have been obtained with tung trees. Drosdoff
and Gilbert4 found that, in a copper-deficient area, 1/2 pound of
20 percent superphosphate applied to the soil around one-year-old
tung trees did not increase the incidence of copper deficiency
symptoms in comparison with those trees to which no superphos-
phate was applied. They found also that a soil application to the
one-year-old trees of 1 ounce of copper sulfate plus 1/ pound of
superphosphate was just as effective in correcting the copper
deficiency symptoms as the 1 ounce of copper sulfate alone.
Hamilton and Gilbert (8) also found no indication that super-
phosphate applied to one-year-old trees affected the incidence of
copper-deficiency symptoms.
Starting with three-year-old trees in 1943 in a copper-defici-
ent area, Drosdoff and Sims5 found that 1 pound of superphos-
phate per tree in April 1943, 2 pounds in July 1944, and 4 pounds
in May 1945, applied along with 4 ounces of copper sulfate, was
no less effective in correcting and preventing copper deficiency
symptoms than the copper sulfate applied alone.
In unpublished data from an experiment previously cited (6)
with eight-year-old trees, analyses were made of leaf samples
collected from a number of plots receiving different fertilizer
treatments. The phosphorus content of the leaves showed no
significant relation to either the copper content of the leaves or
the degree of copper deficiency symptoms. Assuming that the
phosphorus content of the leaves is proportional to the phos-
phorus available in the soil, then this experiment gives further
evidence that the application of phosphate to the soil has no
adverse effect on the copper intake by the tung tree.

Recommendations for Control
The experimental work herein reported, that of Drosdoff and
Dickey (4) and others (6, 8, 11) has shown that copper defici-
ency of tung can be controlled by soil and spray applications of
copper sulfate.
There is a variation on the same trees from season to season
in the severity of copper deficiency symptoms and a decided vari-
ation in the time of appearance of symptoms. Copper-deficiency
symptoms were widespread, very severe and developed early in
the season in 1942 and 1943, but in 1944 they were less severe
and appeared later in the season. Under some conditions and in
4 Unpublished data.
i Unpublished data.







Florida Agricultural Experiment Station


certain locations, soil applications of copper sulfate which in one
season produced adequate control failed to do so the following
season, even though maximum amounts were applied. Also,
there is a wide variation between areas in degree of deficiency
in the same orchard.
For soil applications, copper sulfate was found in the experi-
ments reported herein to be equally effective, whether applied as
the dry salt or in solution. When copper sulfate was applied in
solution, less material was required to produce the same results
than when it was applied to the soil as the dry salt. This ad-
vantage was offset by the facts that the copper solution is not
as easy to apply as the dry salt, it is slightly caustic to the per-
sons handling it, and time-consuming trips from the field to the
water supply are necessary. Furthermore, the copper sulfate
solution must be applied separately, whereas the dry salt may be
mixed with regular fertilizer or with other micro-element car-
riers such as zinc, manganese and magnesium sulfates. Conse-
quently, when soil applications are to be used, the dry salt is
recommended.
In northern peninsular Florida, where copper deficiency oc-
curs, tung plantings should be carefully watched from their intia-
tion for the appearance of symptoms. If symptoms develop it is
probably advisable to treat all trees in the planting. On certain
soil types such as Arredondo and Gainesville loamy fine sand and
Ft. Meade fine sand, which are very low in copper in some areas,
it may be advisable to apply copper as a regular practice. It is
suggested that, for newly transplanted trees, soil applications of
the dry salt be made in the spring at the rate of 1/ to 1 ounce of
copper sulfate per tree. With the trunk as the center, the copper
sulfate is spread evenly over the soil in a circle which has a
diameter of 2 to 3 feet. If satisfactory response has not been
obtained by mid-summer, any affected trees should receive a
second application of an equal amount. Ordinarily 1 ounce of
copper sulfate is about the maximum amount that can be given
in 1 application to one-year-old trees without danger of burning
the foliage. Therefore, if more than 1 ounce of copper sulfate
is needed, it should be split into 2 applications.
Copper sulfate can be applied in the spring (March to May)
to two-year-old tung trees at the rate of 1 to 3 ounces per tree.
With the trunk as the center, the material is spread evenly over
the soil in a circle having a diameter of 3 to 4 feet. The preval-







Copper Deficiency of Tung in Florida


ence of copper deficiency symptoms later in the season will de-
termine the need for a second application.
Three-year-old trees can be given from 2 to 4 ounces of cop-
per sulfate in the spring (March to May), applied broadcast
under the spread of the branches. If copper was applied the first
two years, a second application usually will not be necessary, but
is required if symptoms appear later in the season. From 1/4 to
1 pound of copper sulfate per tree, depending upon size and age
of tree and severity of symptoms, should be broadcast under the
branch spread of older trees. Under some conditions it may be
more economical to apply the copper in the mixed fertilizer.
From 1/ to ll2 percent of CuO supplied as copper sulfate in the
mixed fertilizer is recommended.
Copper sulfate, whether applied to the soil as the dry salt or in
solution, did not always give satisfactory control during the first
season following application. When proper response is not ob-
tained from soil treatments, they should be supplemented with
spray applications of a copper-lime mixture to the leaves, espe-
cially with young trees up to four years old. One application in
the spring of an 8-8-100 copper-lime mixture will give complete
control for the duration of the growing season (Tables 6, 7).
An 8-8-100 copper-lime mixture is prepared by screening 8
pounds of fine mesh or snowform copper sulfate into 100 gal-
lons of water while the spray tank is being filled. Eight pounds
of finely ground hydrated lime is put in a bucket and made into
a thin paste by adding water slowly while stirring vigorously
with a paddle. Then water is added to make 2 gallons. This
mixture is poured slowly into the spray tank to which the cop-
per sulfate previously has been added. It is essential that the
agitator be kept going during the entire procedure and until the
tank has been emptied.
If small hand equipment, such as a bucket pump, compressed
air sprayer or knapsack sprayer is to be used, the copper-lime
mixture can be conveniently mixed in a container such as a
wooden barrel or treated metal drum from which the sprayer
may be filled. The procedure of mixing is the same except that
the solution must be agitated by hand. The spray material in
the barrel or drum must be well agitated each time before the
sprayer is filled.
The method of preparation of a copper-zinc-lime mixture is
similar to that given for copper-lime mixture. The amounts of
copper and zinc sulfates to be used are first dissolved in the







Florida Agricultural Experiment Station


water and the lime added as previously described. Four pounds
of zinc sulfate in 100 gallons of water is sufficient for the control
of zinc deficiency and no additional lime is needed. When the
spraying operations have been completed for the day, the sprayer
should be thoroughly cleaned immediately to avoid corrosion of
metal parts of the machine.
To effect control, it is necessary that the foliage be covered
with the spray, as only those portions of the tree respond which
are sprayed.
Spray applications alone will effect complete control of copper
deficiency but the effect is temporary, necessitating spraying
each year to control the deficiency. Usually after the third or
fourth year, spraying is not necessary either because the cumula-
tive effect of the soil applications is sufficient to eliminate the
copper deficiency or because the root systems have developed
sufficiently to take up enough copper from the soil.
When copper and zinc deficiencies occur simultaneously and are
incompletely controlled by the initial soil applications of copper
and zinc, a spray application of a copper-zinc-lime mixture will
give complete control of both deficiencies.

Summary
The symptoms of copper deficiency of tung are described and
illustrated. To date this disorder has been observed only in the
northern peninsular area of Florida on the following soil types:
Ft. Meade, Arredondo and Gainesville fine sand and loamy fine
sand, and Blanton and Lakeland fine sand. It has not yet been
reported from the other states where tung is grown commer-
cially.
In experimental work herein reported applications of copper
sulfate were found to be equally effective, whether applied to
the soil as the dry salt or in solution or sprayed on the foliage.
Soil applications of 1/ to 1 pound of the dry salt and as little as
1 ounce in 1 pint of water corrected copper deficiency of 8-year-
old tung trees. Soil applications of 1/6 ounce of copper sulfate
in 3/ pint of water corrected the trouble on severely deficient
one-year-old tung trees and 3 ounces applied as the dry salt reduc-
ed considerably the incidence of symptoms. Foliage applications
of copper-lime mixture to one- to four-year-old tung trees cor-
rected the disorder, but a single spray application was effective
for the whole season only when applied at the highest concentra-
tion (8-8-100 copper-lime mixture).







Copper Deficiency of Tung in Florida


Data are presented relative to differences in susceptibility of
tung varieties and seedling progenies to copper deficiency.
Midshoot leaves collected in late summer from tung trees show-
ing copper-deficiency symptoms contained about 3 p. p. m. or less
of copper, while midshoot leaves of treated trees which had re-
covered from copper deficiency and those from normal trees had
about 4 p. p. m. or more of copper in the leaves. The copper.con-
tent of both affected and normal leaves tended to increase late
in the season.
In areas low in copper, the higher the level of nitrogen applied
the more severe was the copper deficiency. In these areas it is
important to maintain a proper nitrogen-copper balance in the
soil.
The application of superphosphate to the soil had no adverse
effect on copper uptake by the tung tree.

Literature Cited
1. Brenchley, Winifred E. Minor elements and plant growth. Biol.
Review Cambridge Phil. Soc. 18: 159-171. 1943.
2. Dickey, R. D. A preliminary report on iron deficiency of tung in Flori-
da. Fla. Agr. Exp. Sta. Bul. 381. 1942.
3. Dickey, R. D., and G. H. Blackmon. Propagation, planting and ferti-
lizing tests with tung oil trees. Fla. Agr. Exp. Sta. Ann. Rept., p. 80.
1941.
4. Drosdoff, Matthew, and R. D. Dickey. Copper deficiency of tung trees.
Proc. Amer. Soc. Hort. Sci. 42: 79-84. 1943.
5. Dyal, R. Stanley, and Matthew Drosdoff. Physical and chemical prop-
erties of some important soils of the southeast used for the production
of tung oil. Soil Sci. Soc. Amer. Proc. 8: 317-322. 1944.
6. Gilbert, S. G., F. S. Lagasse, G. T. Sims, J. Hamilton and A. Nason.
The copper-nitrogen balance in the tung tree. Proc. Amer. Tung Oil
Assoc. 11: 55-59. 1945.
7. Gilbert, S. G., H. M. Sell and Matthew Drosdoff. The effect of copper
deficiency on the nitrogen metabolism and oil synthesis of the tung
tree. Plant Physiol. 21: 290-303. 1946.
8. Hamilton, Joseph, and S. G. Gilbert. The relation of fertilization with
copper and nitrogen to copper deficiency symptoms, leaf composition,
and growth of tung. Proc. Amer. Soc. Hort. Sci. 50: 119-124. 1948.
9. Harris, Henry C. Copper deficency in relation to the nutrition of oats.
Soil. Sci. Soc. Amer. Proc. In Press. 1948.
10. Jamison, V. C. The effect of phosphates upon the fixation of zinc and
copper in several Florida soils. Proc. Fla. State Hort. Soc. 56: 26-31.
1944.








32 Florida Agricultural Experiment Station

11. Loustalot, A. J., F. W. Burrows, S. G. Gilbert and Alvin Nason.
Effect of copper and zinc deficiencies on the photosynthetic activity of
the foliage of young tung trees. Plant Physiol. 20: 283-288. 1945.
12. Mowry, Harold, and A. F. Camp. A preliminary report on zinc sulfate
as a corrective for bronzing of tung trees. Fla. Agr. Exp. Sta. Bul.
273. 1934.
13. Piper, C. S. Investigations on copper deficiency in plants. Jour. Agr.
Sci. 32: 143-178. 1942.
14. Reuther, Walter, and R. D. Dickey. A preliminary report on frenching
of tung trees. Fla. Agr. Exp. Sta. Bul. 318. 1937.
15. Riceman, D. S., C. M. Donald and S. T. Evans. Further investigations
on copper deficiency in plants in South Australia. Council Sci. Ind.
Res. (Aust.) Pamph. 96. 1940.
16. Shear, C. B., and H. L. Crane. Nutrient-element balance. Science in
Farming. U.S.D.A. Yearbook of Agriculture, 592-601. 1943-1947.
17. Shear, C. B., H. L. Crane and A. T. Myers. Nutrient-element balance:
a fundamental concept in plant nutrition Amer4 Soc. Hort. Sci. 47:
239-248. 1946.




University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs