• TABLE OF CONTENTS
HIDE
 Title Page
 Credits
 Table of Contents
 Fig. 2
 Introduction
 Plan of experiments
 Various formulas and single elements...
 Different amounts of fertilizers...
 Time of fertilizer applications...
 Sulphate of potash and muriate...
 Potash and no potash compared
 Comparison of different ammonia...
 Soil amendments
 Summary and discussion
 List of references














Group Title: Bulletin - University of Florida Agricultural Experiment Station ; 270
Title: Fertilizer experiments with pecans
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 Material Information
Title: Fertilizer experiments with pecans
Series Title: Bulletin - University of Florida Agricultural Experiment Station ; 270
Physical Description: Book
Language: English
Creator: Blackmon, G. H.
Ruprecht, R. W.
Publisher: University of Florida Agricultural Experiment Station
Publication Date: 1934
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Bibliographic ID: UF00027678
Volume ID: VID00001
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Rights Management: All rights reserved by the source institution and holding location.

Table of Contents
    Title Page
        Page 1
    Credits
        Page 2
    Table of Contents
        Page 3
    Fig. 2
        Page 4
    Introduction
        Page 5
    Plan of experiments
        Page 6
        Page 7
    Various formulas and single elements compared
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
    Different amounts of fertilizers compared with manure
        Page 16
        Page 17
    Time of fertilizer applications compared
        Page 18
        Page 19
        Page 20
        Page 21
    Sulphate of potash and muriate of potash compared
        Page 22
        Page 23
        Page 24
        Page 25
    Potash and no potash compared
        Page 26
        Page 27
        Page 28
        Page 29
    Comparison of different ammonia sources
        Page 30
        Page 31
        Page 32
        Page 33
        Page 34
        Page 35
        Page 36
        Page 37
        Page 38
    Soil amendments
        Page 39
        Page 40
    Summary and discussion
        Page 41
        Page 42
        Page 43
        Page 44
        Page 45
        Page 46
        Page 47
    List of references
        Page 48
Full Text


August, 1934


UNIVERSITY OF FLORIDA
AGRICULTURAL EXPERIMENT STATION
GAINESVILLE, FLORIDA
Wilmon Newell, Director





FERTILIZER EXPERIMENTS


WITH PECANS


By G. H. BLACKMON and R. W. RUPRECHT


Fig. 1.-Moore pecan trees in the source of ammonia test, Jefferson
County. Trees set in 1919 and photographed in 1931. Experiment begun
in 1924. A, fertilized; B, unfertilized.


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


Bulletin 270










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
Harol I Mowry, M.S.A., Asst. Dir., Adm.
J. Francis Cooper, M.S.A., Editor
R. M. Fulghum, B.S.A., Assistant Editor
Jefferson Thomas, Assistant Editor
Ida Keeling Cresap, Librarian
Ruby Newhall, Administra ive Manager
K. H. Graham, Business 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, M.S., Associate
W. A. Carver, 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
W. M. Neal, Ph.D., Associate in Animal
Nutrition
D. A. Sanders, D.V.M., Veterinarian
M. W. Emmel, D.V.M., Asst. Veterinarian
W. W. Henley, B.S.A., Asst. Animal Hus-
bandman
P. T. Dix Arnold, B.S.A., Assistant Dairy
Husbandman

CHEMISTRY AND SOILS
R. W. Ruprecht, Ph.D., Chemist**
R. M. Barnette, Ph.D., Chemist
C. E. Bell, Ph.D., Associate
H. W. Winsor, B.S.A., Assistant
H. W. Jones, M.S., Assistant

ECONOMICS, AGRICULTURAL
C. V. Noble, Ph.D., Agricultural Economist**
Bruce McKinley, A.B., B.S.A., Associate
Zach Savage, M.S.A., Assoc:ate
A, H. Spurlock, M.S.A., Assistant

ECONOMICS, HOME
Ouida Davis Abbott, Ph.D., Specialist**
L. W. Gaddum, Ph.D., Biochemist
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
J. W. Kea, B.S.A., Assistant

HORTICULTURE
A. F. Camp, Ph.D., Horticulturist**
G. H. Blackmon, M.S.A., Horticulturist
A. L. S'ahl, 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. Tis'ale, Ph.D., Plant Pathologist**
George F'. Weber, Ph.D., Plant Pathologist
R. K. Voorhees, M.S., Assistant
Erdman West, M.S., Mycologist
Lillian E. Arnold, M.S., Assistant Botanist

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


BOARD OF CONTROL

Geo. H. Baldwin, Chairman, Jacksonville
A. H. Blanding, Bartow
A. H. Wagg, West Palm Beach
Oliver J. Semmes, Pensacola
Harry C. Duncan, Tavares
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
R. M. Crown, B.S.A., Asst. Agronomist
Jesse Reeves, Farm Superintendent

CITRUS STATION, LAKE ALFRED
John H. Jefferies, Superintendent
Geo. D. Ruehle, Ph.D., Associate Plant
Pathologist
W. A. Kuntz, A.M., Assoc. Plant Pathologist
B. R. Fudge, Ph.D., Associate Chemist
W. L. Thompson, B.S., Asst. Entomologist

EVERGLADES STATION, BELLE GLADE
A. Daane, Ph.D., Agronomist in Charge
R. N. Lobdell, M.S., Entomologist
F. D. Stevens, B.S., Sugarcane Agronomist
G. R. Townsend, Ph.D., Asst. Plant Patholo-
gist
B. A. Bourne, Ph.D., Sugarcane Physiologist
J. R. Neller, Ph.D., Biochemist
R. W. Kidder, B.S., Asst. Animal Husband-
man
Ross E. Robertson, B.S., Assistant Chemist

SUB-TROPICAL STATION, HOMESTEAD
H. S. Wolfe, Ph.D., Horticulturist in Charge
W. M. Fifield, M.S., Asst. Horticulturist
Stacy 0. Hawkins, M.A., Assistant Plant
Pathologist

WEST CENTRAL FLORIDA STATION,
BROOKSVILLE
W. F. Ward, M.S.A., Asst. Animal Husband-
man 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
R. E. Nolen, M.S.A., Asst. Plant Pathologist
Cocoa
A. S. Rhoads, Ph.D., Plant Pathologist
Hastings
A. H. Eddins, Ph.D., Plant Pathologist
Monticello
SAssistant Entomologist
Bradenton
David G. Kelbert, Asst. Plant Pathologist
Sanford
E. R. Purvis, Ph.D., Assistant Chemist,
Celery Investigations





















CONTENTS
Page
Introduction ...----.........--- .. .. ...... 5
Plan of Experiments..................................................... ............ 6
Various Formulas and Single Elements Compared........-......--.-.--...-...... 8
Curtis and Kennedy ................ ...... ................................. 8
Frotscher..----- --... ..... .. .....----- .... .. ......- -...... 12
Schley...... .... -- ..-- .- --- .--- ..- ......... ........ ... .... .......... .. ..... 13
Different Amounts of Fertilizers Compared with Manure. ........-............. 16
Time of Fertilizer Applications Compared .................. ..- ......-......... 18
Sulphate of Potash and Muriate of Potash Compared .......-................... 22
M oneym aker........ ...- -- .... ............. ...... .................... 22
M oore ........ ..... ...... ........... .....- ............. 22
Schley.......-.- -- ----- .....-...... -.----- .... ..... -. .. ............. 24
Potash and No Potash Compared............ .... .... .......... .... .... ........... 26
M oore.....................--.................- ................ .. 26
M oneym aker............................ ..-.. ....-............................... .... 27
Comparison of Different Ammonia Sources.......-......................... 30
Moneymaker ......... --- ---- ......-- ..... ...... ....... 30
Moore------- ............. .... .......... -- ...- ..... ......... 34
Schley..........---------- ... ... .... .. -... ... .. ............ 35
Stuart.......... ........- ..... -- ........ ........ .... .. 37
Soil Amendments --...----.. ..-..-... ........-- ----- ....... 39
Summary and Conclusions ............. ............-...................... 41
Acknowledgments --. ......... ...... ..~~... -.......... .. 48
List of References ......... ....... .....-........... ....-... 48





































1909 1919 1920 1921 1922 1923 1924 192S 1926 1927 1928 1929 1930 1931
Fig. 2.-Chart showing production of pecans in Florida in pounds of A,
named varieties, and B, seedlings, with the total shown in C. (Statistics
from U. S. D. A. Bureau of Agricultural Economics.)


"/
C-







FERTILIZER EXPERIMENTS

WITH PECANS

By G. H. BLACKMON and R. W. RUPRECHT

INTRODUCTION
The importance of fertilizing pecan trees in Florida has been
appreciated by certain growers from the beginning of commer-
cial nut production in this area. With the growth of pecan
production in Florida from 307,632 pounds in 1909 to 2,350,000
pounds in 1931 (Fig. 2), it is seen that this industry has become
of increasing importance in northern and western Florida.
At various times since 1896 (see List of References in the
back of this bulletin) different investigators and writers have
suggested the advisability of fertilizing pecan trees, and have
indicated that complete fertilizers are desirable, with the fer-
tilizers for young trees carrying fairly high percentages of nitro-
gen and those for older trees analyzing a little lower in nitrogen
but higher in potash*. The published information on fertilizing
pecans in Florida, however, is limited.
As a consequence, the kinds and amounts of fertilizers applied
to pecan trees in Florida have varied widely, ranging from none
at all to fairly large quantities of complete mixtures. It often
happened that where fertilizer applications were made, they
were inadequate, and in years when large crops of nuts were
set the trees made insufficient twig growth while the nuts were
developing. As a result of such depleted condition, subsequent
yields would be light until such time as would be required for
the trees to revive and again make adequate growth for nut
production.
It should be pointed out, however, that it is impossible to
produce sufficient growth to give quantity yields with fertilizers
alone, as there must be adequate soil moisture available at all
times for the proper functioning of the tree, otherwise there
will be poor growth and light yields, regardless of the amount
and kinds of fertilizers used. Pecan pests have also been im-
portant factors in causing light yields. Much of the so-called
alternate bearing of pecans has been due partly to the losses
More recent investigations, however, have indicated the advisability of
maintaining a fairly high nitrogen content in fertilizers for older trees,
particularly on light soils.






Florida Agricultural Experiment Station


sustained through the ravages of insects and diseases and partly
to low vigor caused by improper nourishment.

PLAN OF EXPERIMENTS
When the present pecan investigations were begun at the
Florida Agricultural Experiment Station in 1923, one of the
projects outlined was a study of the fertilizer requirements of
pecan trees. Consequently, a number of cooperative field ex-
periments were begun, some in 1924, others in 1925, and one
in 1926; and in two of the orchards several plots were added
at a later date but not in such way as to impair the value of
the results of the original plots. The varieties included in these
experiments were: Curtis, Frotscher, Kennedy, Moneymaker,
Schley, Stuart and Success. In all experiments except one the
plots contained four or more trees each. The results, however,
are given in tree averages and the yields recalculated to an acre
basis of 17 trees so as to magnify the differences and show what
orchard yields would be under similar conditions.
These experiments were located on soils of the Bladen, Cox-
ville, Norfolk and Orangeburg series.
The percentages of nitrogen, phosphorus and potassium in
the soil series on which the pecan experiments were conducted
are presented in Table 1, which is taken from Agricultural Ex-
tension Service Bulletin 42, The Soils of Florida, by O. C. Bryan.
While the information given does not represent the analyses of
the soils where the trees were growing, it does show the general
average analysis of the soil series concerned. Analyses of the
Coxville soils are not given in Table 1, but this series is closely
related to Bladen.
TABLE 1.-THE PERCENTAGE OF NITROGEN, PHOSPHORUS, AND POTASSIUM
IN THE SOIL SERIES ON WHICH PECAN FERTILIZER EXPERIMENTS WERE
CONDUCTED.
Percent Percent Percent
Series Nitrogen Phosphoric Acid Potassium Oxide
(N) (P,0_) (K_,O)
Bladen .......-- ------... .... .107 .027 .048
Norfolk .- ................ .050 .019 .011
Orangeburg --....------ .193 .190 .052

The pH determinations of the soils occupied by the various
plots of all experiments were made and are shown in the tables
in connection with the different fertilizer treatments, but no






Fertilizer Experiments With Pecans


attempt was made to correlate this factor with growth and yield
of pecan trees.
The experiments were designed to test the effects on the
growth of pecan trees and on the yield of nuts of ammonia and
potash from different sources, single elements, various formulas
containing different percentages of plant foods, varying the
amounts of fertilizer per tree, and the number of applications
per year of complete fertilizers.
In all formulas the percentage of nitrogen is given as the
ammonia equivalent and is stated first, with the phosphoric acid
second and the potash third. Unless otherwise indicated, the
phosphoric acid and potash in all experiments were derived from
superphosphate and sulphate of potash, respectively.
Only one application of fertilizer was made annually, either
in February or March, before bud growth manifested itself, with
the exception of the Duval County Experiment in which there
were several applications made during the year. A circular
area around the tree trunk was fertilized, two, three, or with
some of the largest trees, even six feet greater in diameter than
that covered by the spread of the branches of the trees. This
resulted in practically broadcasting the fertilizer in the orchards
containing the largest trees in which experiments were located.
Growth Increments.-The growth increments were computed
from the area of the trunk cross-sections of all trees in each
plot and averaged, rather than considering the circumferences
only. This method of calculating relative growth of trees, dis-
cussed by Reed (see No. 9 in List of Literature), gives a more
accurate indication of tree development than where circumfer-
ences only were considered.
Samples of nuts from the various experiments were obtained
as often as possible and the following measurements and analyses
were made on each: Average length and diameter, number of
nuts per pound, percentage of kernel in the nuts and the per-
centage of moisture, fat, protein and ash in the kernels. The
average length and diameter were based on the measurement
of 30 nuts in each sample, and the other determinations were
made on about one pound samples. Moisture was determined
by drying the ground kernels in a vacuum oven at 650 C. for 10
hours, the dried samples were then extracted with anhydrous
ethyl ether to determine the fat content. Nitrogen was deter-
mined by the Kjeldahl-Gunning-Arnold method and the result
multiplied by 6.25 to obtain the protein content.






Florida Agricultural Experiment Station


VARIOUS FORMULAS AND SINGLE ELEMENTS
COMPARED

A number of experiments to test the effect of various fertilizer
formulas and single elements on growth and yield of Curtis,
Kennedy, Frotscher, and Schley trees were located in Bradford,
Columbia and Jefferson counties. A discussion of the results
will be considered separately by varieties and location.

CURTIS AND KENNEDY
The trees of the Curtis and Kennedy varieties were in an
orchard located in Bradford County and were set in 1919 and
1920, respectively, on Coxville fine sandy loam soil, and the
experiment was begun in 1924 when the Curtis trees were five
years old and the Kennedy four. The soil was given ordinary
care and the orchard was intercropped with corn, peanuts, and
velvet beans throughout the duration of the experiment. No
spraying was practiced for the control of insects and diseases,
although the walnut caterpillar was destroyed by hand when-
ever it made its appearance in the trees. However, since these
two varieties are only slightly susceptible to pecan scab, there
were no appreciable losses experienced from this disease.
The trees in this orchard were divided into eight plots for the
Kennedy and seven for the Curtis, all of which were fertilized
except one plot of each variety which was left unfertilized as
a check. The fertilized plots contained five trees each, while
the checks contained four Kennedy and six Curtis. The growth,
yield, and other general information are given in Table 2. The
fertilizer formulas applied in each plot were as follows: (Plot
6 being omitted in the Curtis block) 1, 4-6-2;* 2, 4-6-6; 3, 6-6-4;
4, 8-4-4; 5, 6-9-2; 6, 6-4-6 and 7, 4-8-4. The ammonia in all mix-
tures was supplied by sulphate of ammonia, blood, and cotton-
seed meal, and the phosphoric acid and potash furnished by
superphosphate and sulphate of potash, respectively.
Growth.-In considering the growth of the trees of these
varieties, the data in Table 2 show that the greatest amount
of wood development of the Kennedy was made by the trees
that received a 4-8-4 fertilizer, with the 8-6-2 a very close second.
These plots produced an average total growth increment per
tree of 45.3 and 43.3 square inches, respectively, while the check
All formulas are stated in the order of ammonia, phosphoric acid and
potash.





Fertilizer Experiments With Pecans


made only 21.0 square inches during the time the experiment
was conducted.
With the Curtis, the most growth was made by the trees
fertilized with the 6-6-4 mixture, and second, those that received
the 4-6-6. They made an average total wood production per
tree of 82.4 and
75.6 square inch-
es, respectively,
while the checks
made an average
growth of 49.2
s q u ar e inches
each. Two of the
treated plots pro-
duced slightly less
wood growth
than that of the
check. These were
fertilized with
mixtures that
were relatively
high in ammonia;
one received ap-
plications of an 8-
6-2 and the other
an 8-4-4. (Fig. 3.)
Yield. The
average annual
yield of the Ken-
nedy and Curtis
trees for each
plot is shown in
Table 2. The Ken-
nedy trees pro-
duced a few nuts Fig. 3.-Kennedy trees, Bradford County. A, un-
from the begin- fertilized check; B, fertilized.
ning of the experiment but the bulk of the yield was made from
1927 to 1931, or the seventh to eleventh years, inclusive, after
the trees were set.
These data show that the Kennedy trees that gave the high-
est yield were fertilized with a 4-8-4, with the 6-4-6 and 8-6-2





Florida Agricultural Experiment Station


close second and third, and averaged annually 11.20, 10.98 and
10.26 pounds per tree, respectively, for the period indicated.
The lowest yield of the fertilized plots was produced by the
trees that received annual applications of an 8-4-4 mixture, and
averaged annually 2.9 pounds; even this was a decided increase
over the checks, which averaged one-tenth pound per tree.
If the increased yields for 1927-31 inclusive are computed on
an acre basis of 17 trees, the differences are more clearly known.
When so calculated the productive ability of Kennedy trees
growing under similar conditions as those worked with, when
adequately fertilized, is established. On this basis the increased
production of nuts would amount to 943.5 pounds per acre for
Plot 7, in which the 4-8-4 mixture was used, which would rep-
resent an annual yield of 188.7 pounds of nuts per acre greater
than where no fertilizers were applied.
Although the Curtis trees were only one year older than the
Kennedy, they gave a much higher yield of nuts, but there was
not as great a difference between the fertilized and check trees
as with the latter. All fertilized plots produced a larger quantity
of nuts per tree than the one unfertilized. The highest yields
were made by the trees in Plot 2 that received applications of
a 4-6-6 mixture, and second Plot 7, which received a 4-8-4, an
average of 18.24 and 13.34 pounds of nuts per tree annually,
respectively, while the unfertilized trees produced an average
of 6.34 pounds each. An acre of 17 trees, producing a quantity
of nuts comparable to that of the highest yielding fertilized
trees in Plot 2, would show a production of 1,011.5 pounds of
nuts more than where no fertilizer was applied which would
amount to an annual increase of 202.3 pounds per acre for the
period 1927-1931.
The trees in Plot 1 that were fertilized with an 8-6-2 produced
only 7.28 pounds per tree annually which was the lowest of all
those treated, but was slightly higher than the production of
the check. However, it should be pointed out that the trees in
this plot were located in a portion of the orchard where the soil
was not as well drained as in the others. This doubtless was
the main contributing factor in holding down the yield, as well
as in the failure of the trees to make adequate growth.
Table 3 gives the average analyses of Curtis and Kennedy.
Considering first the Curtis; Plot 4 fertilized with an 8-4-4
fertilizer produced the heaviest nuts and the check plot had the
highest percentage of kernels in the nuts, while Plot 7 which








TABLE 2.-EFFECTS OF DIFFERENT FERTILIZER FORMULAS ON GROWTH AND YIELD OF PECANS.


Plot pH of Soil Growth Increment Per Tree
No.* 0-9 Inches Area of Trunk Cross Section in Square Inches
1932** 1924 1925 192 61l 1927 1928[ 1929 1930 1931 Total 1924 1925 1926 1

KENNEDY-Trees Set 1920


2.7 4.7

2.7 3.9

1.7 4.0

1.5 3.5

2.5 3.4

2.9 4.7

3.2 5.9

2.1 2.2


5.6 4.7

3.5 3.4

1.8 2.9

3.9 3.7

2.4 3.1

4.7 4.1

5.4 4.8

1.6 2.0


7.1 43.3 0.0 1.0

6.9 35.0 0.1 0.7

3.5 23.4 0.1 0.3

5.6 30 1 0.0 0.3

5.0 30.0 0.2 0.5

7.8 39.7 0.3 0.3

7.5 41.3 0.2 0.8

51 21.0 0.1 0.1

CURTIS Trees Set 1919


1 4.9 3.3 5.6 6.2 4.7 4.7 6.5 6.6 7.5 45.1

2 5.3 5.6 8.0 9.5 10.5 9.8 102 11.8 19.2 75.6

3 5.2 5.8 8.7 8.9 12.9 10.7 11.9 11.9 11.6 82.4

4 5.0 3.8 5.3 6.1 5.0 5.6 7.1 8.1 7.4 48.4

5 5.0 4.3 7.5 7.1 8.3 9.1 8.7 9.6 10.i 35.1

7 5.3 5.4 7.4 9.3 9.6 10.3 10.9 10.9 10.6 74.1

eck 5.4. 4 4 5.9 5.1 5.2 6.7 6.6 7.0 8.2 49.1

Pounds of fertilizer applied per tree annually:
Kennedy, 5, 1924; 8, 1925: 13, 1926; 15, 1927-31 inclusive.
Curtis, 5, 1924; 8, 1925; 13, 1926: 15, 1927; 25, 1928-31 inclusive.
pH of a composite soil sample at start of experiment, 5.4,


0.2 0.1

0.4 0.5

0.5 0.7

0.1 0.7

0.2 0.5

0.6 1.4

0.2 1.2


Yield Per Tree in Poun 's


1927 1928 1929| 1930/ 1931 Total A A1927-31


0.2 6.8

1.1 7.1

0.4 2.3

0.3 1.8

0.5 1.7

1.9 6.9

1.3 4.5

0.1 0.0


4.0

6.0

1.8

2.3

3.2

9.9

7.9

0.0


3.6 2.4 9.4 3.4 7.3 13.9 40.3

9.2 9.7 21.9 7.8 15.6 36.2 101.3

4.8 6.6 13.8 6.1 4.6 30.0 67.1

3.6 4.9 8.9 1.9 4.4 25.5 50.0

4.5 10.6 12.5 10.6 7.1 24.8 70.8

8.1 8.1 16.6 4.6 9.6 27.8 76.8

2.7 4.6 5.8 6.1 1.4 13.8 35.8
_______ .___ ______ ___ ____


1

2

3

4

5

6

7

Check


4.4

5.0

5.0

5.0

4.9

5.0

4.8

3.8


10.26

8.14

3.34

2.90

4.24

10.98

11.20

0.10




7.28

18.24

12.22

9.12

13.12

13.34

6.34


Ch






Florida Agricultural Experiment Station


received a 4-8-4 fertilizer had the highest fat and lowest protein
content. With the Kennedy the nuts from Plot 3 fertilized with
a 6-6-4 fertilizer had the highest percentage of kernel, while
Plot 5 which received a 6-8-2 fertilizer had the lowest kernel
content, the lowest fat content and the highest protein and ash
contents. Plot 6 which received a 6-4-6 fertilizer had the lowest
protein and ash contents.
TABLE 3.-EFFECT OF VARIOUS FERTILIZER FORMULAS ON SIZE AND
COMPOSITION OF PECAN NUTS'.
Size of Nuts II Percent Kernel and Analyses
Plot No. No. Diiam. Length Percent Percent Percent Percet Pent
per lb. 16th in. 16th in.1 Kernel H..O Fat Protein Ash
CURTIS

1 84 13 24 55.80 3.37 73.41 9.00 1.44
2 84 13 25 56.59 3.29 73.75 8.70 1.36
3 84 13 25 56.03 3.18 73.19 9.31 1.46
4 78 13 25 54.88 3.20 73.50 9.10 1.43
5 81 13 25 56.68 3.08 73.75 9.10 1.42
7 80 13 25 56.62 3.02 74.15 8.28 1.43
Check 80 13 24 57.50 2.88 73.91 8.99 1.41
KENNEDY

1 72 13 26 52.10 3.05 73.07 9.85 1.53
2 64 14 27 52.64 3.01 74.22 9.27 1.50
3 65 13 27 52.97 3.17 74.19 9.57 1.52
4 65 13 27 51.86 3.37 73.57 9.83 1.49
5 66 14 27 51.34 3.51 71.41 10.57 1.60
6 64 14 27 52.51 3.07 73.76 9.29 1.45
7 66 14 27 52.06 3.23 72.73 10.61 1.53
Check (Yield for only 1 year, not tabulated)
Average for 5 years.
** Fertilizer formula by plots, both varieties: 1, 8-6-2; 2, 4-6-6; 3, 6-6-4;
4, 8-4-4; 5, 6-8-2; 6, 6-4-6; 7, 4-8-4; check, nothing.

FROTSCHER
Comparisons of different formulas and single elements were
made with the Frotscher variety in tests located in Columbia
County. The trees were set in 1912 on Norfolk sandy loam soil






Fertilizer Experiments With Pecans


and the work was begun in 1924 when they were 12 years old.
There were 10 plots of five trees each in this orchard; nine were
fertilized and one was left unfertilized as a check. The fertiliz-
ers used in the different plots were as follows: Plots 1 and 3,
4-8-4; 2 and 4, 6-8-4; 5, 4-8-6; 6, 6-8-6; 7, phosphorus only; 8,
potash only; and 9, phosphorus and potash. In the plots where
the complete fertilizers were applied the sources of ammonia
were all inorganic in 1, 2, 5, and 6; and a mixture of inorganics
and organic in 3 and 4.
The resulting yields of this variety were not very satisfactory,
and while the Frotscher is generally considered to be a shy
bearing variety this was not the main reason for the light yields
in this orchard. The very poor showing was due largely to
heavy losses each spring as a result of severe infestations of
the leaf case-bearer. It is believed that the production would
have been appreciably higher in this orchard if the trees had
been sprayed annually to control this pest. The results in growth
and yield of the Frotscher trees are presented in Table 4.
Growth.-The greatest growth increment in the Frotscher
orchard was made by the trees in Plot 4 that were fertilized
with a 6-8-4, and the second highest, a 6-8-6. In all plots, ex-
cept 1 and 5, the growth increment was greater where the
complete fertilizer was applied than where ammonia was omitted,
and the least growth of all was made by the trees that received
only phosphoric acid and potash.
Yield.-The yield of the Frotscher trees in this experiment
was higher in all fertilized plots than in the check, except in
the plot where only phosphoric acid and potash were applied.
The highest total production of nuts was made by the trees in
the plot which also made the largest growth and where a 6-8-4
was used in which the ammonia was derived from both organic
and inorganic sources.
Table 5 gives the analyses of the Frotschers grown in Colum-
bia County. Phosphoric acid alone produced the heaviest nuts
with the highest fat content and the lowest ash. Varying the
percentage of ammonia and potash did not seem to have any
influence on the composition of the nuts produced in this ex-
periment.
SCHLEY
An experiment to test the effects of single elements compared
with 4-8-4 and 4-8-6 formulas, on growth and yield of Schley
trees, was conducted in an orchard located in Jefferson County.











TABLE 4.-EFFECTS OF DIFFERENT FERTILIZER FORMULAS AND SINGLE ELEMENTS OF GROWTH AND YIELD OF PECANS.


pH of Soil
0-9 Inches A
1932** 1924


Growth Increment Per Tree I Yield Per Tree in Poun's
rea of Trunk Cross Section in Square Inches _j
1925J 1926_ 1927 11928 1929 1930 1931 ( Total |1 1924 1925 1926 1927 1928 19291 1930 1931
FROTSCHER-Trees Set 1912


Plot
No.*



1

2

3

4

5

6

7

8
9

Check


1

2

3

4

5

7

Check


2 3.4

8 2.6

9 2.4

9 3.1

2 2.6

1 2.1

7 0.8

5 1.3

4 1.4

4 2.0
SCHLEY












.I i i i


10.1 .

8.0 .

9.8


45.3 0.7 6.5

53.0 0.2 4.3

46.3 0.2 6.2

72.1 0.5 4.4

36.1 0.6 93

54.2 0.3 3.5

45.5 0.9 10.0

34.4 4.6 5.8

26.4 0.3 2.4

28.3 0.6 4.3
-Trees Set 1910***

48.2 7.9 31.1

33.6 16.9 32.1

43.2 7.4 17.8

46.1 9.0 26.4

69.9 3.5 47.0

53.5 6.1 39.5

49.9 7.0 28.8


Pounds of fertilizer applied per tree annually:
Frotscher: 40, 1924; 50, 1925; 60, 1926-31 inclusive.
Schley: 50, 1924-25; 75, 1926-29 inclusive. Applications are equivalent to amounts
**pH of a composite soil sample at start of experiment: Frotscher, 6.4; Schley, 7.0.
*** Schley experiment discontinued in 1929.


3.2 0.1

3.1 0.1

2.5 0.1

2.5 0.9

1.7 0.9

1.7 0.1

1.9 2.2

1.8 0.7

0.9 0.2

1.4 2.7


1.2 35.2

2.7 34.2

0.5 24.0

1.7 34.2

0.6 44.4

2.5 32.8

0.9 23.6


Total Avg. Annual


21.3

17.9

17.4

29.1

22.1

16.3

23.0

17.4

7.4

13.1


contained in complete mixtures.


7.3 4.7

3.2 2.9

6.1 4.1

5.7 6.1

9.7 9.1

8.1 6.5

6.2 6.5


. .






Fertilizer Experiments With Pecans


The trees were set in 1910 on Norfolk fine sandy loam soil and
were well developed as to size at the time the work was started
in 1924. The orchard was divided into seven plots for the pur-
pose of making these tests. Six of the plots contained five trees
each and were fertilized as follows: 1, ammonia only; 2, potash
only; 3, phosphorus only; 4, ammonia and phosphorus; 5, 4-8-4;
6, 4-8-8; while the check plot contained 8 trees and was left
unfertilized. The ammonia in the fertilizers for all plots was
derived from inorganic and organic sources in the same ratio.

TABLE 5.-EFFECT OF VARIOUS FERTILIZER FORMULAS ON THE COMPOSITION
OF FROTSCHER PECAN NUTS*.
Size of Nuts |[ Percent Kernel and Analyses
Plot No. | Diam. Length Percent Percent IPercent | Percent I Percent
No.** per lb. 16th in. I 16h in. Kernel HO Fat I Prote:n Ash

1 53 15 26 50.44 3.75 69.21 13.27 1.84
2 53 15 26 49.99 3.75 68.75 12.92 1.91
3 54 15 26 49.37 3.91 67.00 14.57 2.11
4 55 15 26 50.87 3.62 69.37 11.99 1.85
5 53 15 26 50.88 3.68 69.02 13.16 1.90
6 53 15 26 48.79 3.64 69.04 13.64 1.98
7 51 15 26 51.50 3.70 70.73 11.40 1.75
8 52 15 26 50.90 3.75 70.08 11.76 1.87
9 52 15 26 49.69 4.20 68.88 12.74 2.09
Check 54 15 26 50.68 3.59 69.24 12.36 1.93
Six years averaged for plots 1, 4, 7, and check, and five years for all
other plots.
** Fertilizer treatment by plots: 1 & 3, 4-8-4; 2 & 4, 6-8-4; 5, 4-8-6;
6, 6-8-6; 7, phosphorus; 8, potash; 9, 0-8-6; check, nothing.

During the time the experiment was in progress clean culture
was practiced except that an occasional cover-crop was grown
and returned to the soil. Some years there were heavy losses
caused by nut case-bearer infestations, but pecan scab was con-
trolled with a complete Bordeaux spraying program and no ap-
preciable crop damage resulted from attacks of this disease. The
growth and yield, soil pH, and fertilizers applied are given in
Table 4.
Growth.-The two plots, 5 and 7, that were fertilized with the
complete mixtures were the only ones in which the trees showed
a greater growth increment than was made by those in the one





Florida Agricultural Experiment Station


unfertilized. The greatest growth was made by the trees in
the plot where a 4-8-4 was applied, and the least by those that
were fertilized with phosphoric acid alone, which in turn was
only slightly less than that made by the trees in the plot where
potash alone was applied.
Yield.-The highest yield was produced in Plot 2 that received
potash only and averaged 18.66 pounds per tree annually. The
plot where phosphoric acid only was applied yielded only 10.83
pounds per tree annually which was 0.85 of a pound less than
that of the checks. The trees that were second and third high
in production were those in Plots 5 and 7, respectively, where
complete fertilizers were applied, with the trees in Plot 1 that
received ammonia only being fourth high in nut yields.

DIFFERENT AMOUNTS OF FERTILIZERS COMPARED
WITH MANURE
The effect on growth and yield of three different amounts of
two commercial fertilizer mixtures, 4-8-4 and 6-8-4, compared
with manure was studied in a test in Leon County, on Orange-
burg sandy soil. Moneymaker trees set in 1913 and fairly uni-
form in size, but not quite as large as they should have been
for their age at the time the work was started in 1924, were
used.
The orchard was divided into eight plots: 1 fertilized with
manure; 2, 3 and 4 with a 4-8-4; and 5, 6 and 7 with a 6-8-4 com-
mercial mixture, and the eighth left unfertilized as a check.
The fertilized plots contained five trees each and the check plot
three. The ammonia in both commercial fertilizers was derived
from a mixture of inorganic and organic materials. Detailed
information and the response of the trees to the different treat-
ments are given in Table 6.
Growth.-There were only two fertilized plots, 1 and 4, in
which the trees made a greater growth than that made by the
checks and these were fertilized, respectively, with 400 pounds
of manure and 70 pounds of a 4-8-4 commercial mixture per tree
annually, the manured trees making slightly more growth than
the others.
Yield.-The yields were fairly good but not high. The high-
est yielding plot was the one where there was an annual appli-
cation of 400 pounds of manure per tree, with the second highest
being the one fertilized with 30 pounds per tree annually of a
4-8-4 commercial mixture. Considering the manure as having














TABLE 6.-COMPARATIVE EFFECTS OF DIFFERENT AMOUNTS OF FERTILIZERS AND MANURE ON THE GROWTH AND YIELD OF
MONEYMAKER PECAN TREES SET IN 1913.


Plot I H of Soil
No.* 0-9 Inches
1932**



2 .5

3 5.3

1 5.4

5 5.4

6 5.4

7 5.0

Check 5.3


Growth Increment Per Troe
Area of Trunk Cross Section in Sqularc Inches

11921 I 125 1!)26 1927 1928 ', 1921 19 0 i 1!:1 Totall

!.1 I 3. 11. 3.6 11.S 10.1 12. 1.7 67.4

S 11 :1.9 2.8 9.1 .7 I 7 1.: 16.5

8. (1 5.5 4.9 9.3 7.1 S.: 1. 18.3

5.8 6.7 8 4 14.5 11.3 S. 9. 3.0 67.2

11.1 3.o 9.6 1,7 9.2 li.; 1.7 53.0

9. 3." 5.3 4.0 0.0 1.5 7,3 2.7 45.2

S.5 4.5 10.0 1.5 9.9 S.5 .8 1.0 54.6

6.8 5.7 10.6 4.4 11.5 .: 117 3.7 63.7


Yield Per Tree in Pounds

192 1 25 1926 1927 192S 19)2 1030 1:11 Tlotal

1.5 5.1 9.97 1;1.9 12.1 28.6 18.0 67.S 1 7. 0

1.01 7.S 9.1 11.2 12 .0 22.1 10.2 132.0

;3.0 :.S 7.0 ,5.1 1 1. 12.1 21.6 3:1.3 95.7

0.0 01.7 3.0 4.1 .l 1:3.1 20.1 .58.0 105.2

3.4 12.2 8.1 15. 1 4.5 26.1 .1 ,19..2 123.1

(;.0 12.3 5.0 5 8.9 1 1. 1 25.2 8H.0 1116.3

1.0 52 0.8 1.6 2.0 18.0 19.6 10.2 1'2.3 :

1 8.2 3.6 3. 0 3.9 1:.2 1S.1 :38.3 91.0


Pounds of fertilizer applied per tree annually:
Plot 1, Manure 300 lbs. 1921; 400 lbs. 1125-:11 inclusive.
Plots 2 and ri, 20 lbs. 1924; 30 lbs. 1925-31 inclusive.
Plots 3 and 6, 30 lbs. 1924; 50 lbs. 1925-31 inclusive.
Plots 4 and 7, 40 lbs. 1924; 70 lbs. 1925-31 inclusiv,.
** pH of a composite soil sample at start of experiment, 6.2.


An;. Annu

114162

11 .50

11.96

13: 15

113


11.53

11.:7


- (
Cs






~I

Cs







In
C7r


Is


1-








18 Florida Agricultural Experiment Station

an average analysis of .5% ammonia, .5% phosphoric acid and
.5% potash, the 400 pounds applied annually were equivalent
in plant food to about 50 pounds per tree of a 4-4-4 fertilizer.
The highest yielding plots (Table 6) that received the com-
mercial fertilizer were 2, 5, and 6 in which 30, 30 and 50 pounds
per tree were applied annually, a 4-8-4 for Plot 2, and a 6-8-4
for Plots 5 and 6. Of the commercial fertilizers, the small
amounts seemed to give higher yields, but none produced as
many pounds of nuts per tree as did the manure plot. All
treated plots produced yields higher than the check plot.
Table 7 gives the analysis of Moneymaker produced where
different amounts of fertilizer were applied. Increasing the
amount of fertilizer had no apparent effect on the composition
of the nuts, but increasing the ammonia content from 4% to 6%
in the formula apparently lowered the fat content to a slight
extent.
TABLE 7.-EFFECT OF AMOUNT OF FERTILIZER ON SIZE AND COMPOSITION
OF MONEYMAKER PECAN NUTS*.
Size of Nuts 1| Percent Kernel and Analyses
Plot No. Diam. Length ] Percent Percent Percent Percent iPercent
No.* per lb. 16th in. 16th in. Kernel H-O Fat Protein Ash
1 64 15 21 1 39.32 4.43 65.68 11.72 1.72
2 63 15 21 38.76 3.88 66.57 11.85 1.72
3 63 15 21 40.24 3.83 67.18 11.39 1.70
4 62 15 21 40.67 3.89 68.01 11.04 1.66
5 66 15 21 40.37 4.30 65.91 11.79 1.70
6 65 15 21 40.36 4.52 65.62 11.97 1.76
7 66 15 21 38.26 4.17 65.99 11.99 1.78
Check 65 15 21 42.82 4.01 67.25 11.33 1.67

Average for 7 years.
** Plot 1, manure; Plots 2, 3, & 4, 4-8-4; Plots 5, 6 & 7, 6-8-4.

TIME OF FERTILIZER APPLICATIONS COMPARED
In a Duval County experiment, varying the time and number
of applications of a complete fertilizer, applying the phosphoric
acid and potash in one application and the ammonia in more
than one application, were studied. A 4-9-4 mixture was used
in all of the fertilized plots. The ammonia was derived from
nitrate of soda and tankage, with the phosphoric acid being







Fertilizer Experiments With Pecans


supplied in the tankage and superphosphate, while the potash
came from sulphate of potash.
The varieties used were Curtis and Success, trees of which
were set in 1920 on Bladen fine sandy loam soil, and the experi-
ment started in 1925 when the trees were five years old. The
trees were divided into nine plots for each variety, eight of
which were fertilized and one left unfertilized as a check. Each
fertilized plot contained 6 Curtis and 4 Success trees, and the
check 3 and 2, respectively. The complete fertilizers were ap-
plied to PVot 1 during February and June; Plot 2, February,
May and June; Plot 3, February, April, May and June. The
phosphoric acid and potash were applied to Plots 4, 5, 6, 7 and 8
in February. The ammonia applications were made to Plot 4
in April, May, and June; Plot 5, April, June and August; Plot 6,
February and July; Plot 7, January and April; Plot 8, February,
May, July and September.
A cover-crop system of cultivation was practiced in this or-
chard and the trees were sprayed annually for insect and disease
control. Although the productive ability of the soil of this
experiment varied considerably, there were favorable differences
in the growth and yield of the fertilized over the unfertilized
trees. The check plot was located on about an average soil,
somewhat better than that occupied by a majority of the
fertilized plots. The results obtained in growth and yield are
presented in Table 8.
Growth.-There were variations in the amount of growth
made by the trees in the fertilized plots of both varieties, but
the growth made by the trees in all of the fertilized plots was
greater than that made by the checks, except in Plot 8 of the
Curtis, and Plots 7 and 8 of the Success. The most growth of
all the plots was made by the Curtis trees that were fertilized
with a complete mixture in three applications, while the four
applications produced the greatest growth with the Success.
Yield.-The data presented in Table 8 show that all fertilized
plots produced a higher quantity of nuts per tree than where
no fertilizer was applied. The plots which gave the highest
total yield for the duration of the experiment were Curtis 3 and
Success 2, in which the complete fertilizers were applied in four
and three applications, respectively. From 1928 to 1931 the
Success trees in Plot 2 averaged 10.17 pounds each annually,
but for this period the Curtis in Plot 1 produced slightly more
nuts than those in Plot 3, and averaged 16.2 pounds per tree










0



TABLE 8.-COMPARATIVE EFFECTS OF DIFFERENT NUMBERS OF APPLICATIONS OF A 4-9-4 FERTILIZER ON GROWTH AND YIELD
OF PECAN TREES SET IN 1920.

pH of Soil Growth Increment Per Tree Yield Per Tree in Pounds a
Plot No.* 0-9 Inches Area of Trunk Cross Section in Square Inches
SI Avg. Annual for
1932"* i 1i2 1926 1927 19281 1929 1930 1931 Total II 1925 1926 1927 1928 1929 19 0 1931 Total 1928-31

CURTIS

1 5.3 6.6 8.2 7.0 10.0 9.6 9.4 8.4 59.2 0.7 6.4 3.5 27.0 0.6 1.7 35.5 75.4 16.20
2 5.4 5.6 9.1 8.4 8 10.1 10.0 10.5 62.5 0.3 3.6 2.3 19 8 0.3 2.6 28.7 57.6 12 85
3 5.4 5.6 6.5 7.4 7.4 7.9 8 4 8.0 51.2 2.1 3.9 5.7 16.3 0.8 1.2 46.1 76.1 16.10
4 5.4 4.9 6.2 6.7 9.4 8.9 8.4 6.4 50.9 0.4 1.1 1.9 5.4 1.1 0.3 21.4 31.6 7.05
5 5.3 5.3 6.5 5.0 8.2 7.4 7.0 5.4 44.8 0.8 3.1 4.5 5.1 2.4 1.3 36.0 F3 2 11.20
6 5.3 3.5 4.9 4.7 7.3 6.1 9.3 7.6 43.4 0.3 1.7 3.6 7.7 1.3 1.5 15.2 31.3 6.42
7 5.4 2.4 4.1 3.7 6.4 6.1 5.8 4.4 32.9 02 3.1 2.3 8.5 0.9 1.2 21.3 37.5 7.97
8 5.3 2.7 4.1 3.8 6.0 5.4 5.8 4.3 32.1 0.1 2.9 0.4 7.4 1.3 0.02 13.8 25.9 5.62
Check 5.4 6.4 3.6 3.2 2.8 7.4 4.3 4.5 32.2 1.4 0.1 1.4 0.2 0.2 0.01 004 3.4 013

SUCCESS

1 5. 4.6 6.4 56 7.4 6.5 6.9 7.0 44.4 0.9 4.1 6.8 147 1.5 0.8 17.0 45.8 850
2 4.7 5.3 5.4 8.0 81 6.1 840 7.7 48.6 1.0 5.5 36 16.9 0.6 0.4 22.8 50.8 10.17
3 5.0 6.2 6.0 8.1 6.2 7.7 9.4 7.9 51.5 0.9 4.1 3.6 10.5 0.4 0.2 26.2 45.9 9.32
4 5.1 5.6 5.5 6.9 7.1 6.1 6.8 6.4 44.4 0.6 3.5 3.9 7.8 1.4 0.1 289 46.2 9.55
5 5.2 4.9 4.6 5.1 4.7 4.6 5.7 5.3 34.9 1.0 3.5 3.5 5.0 1.3 0.4 17.0 31.7 5.92
6 5.3 4.1 5.5 5.4 5.3 45 4.8 4.6 34.2 0.2 1.2 4.5 2.7 1.1 0.1 10.6 20.4 3.62
7 5.3 2.4 4.9 4.0 5.2 4.1 3.5 3.3 27.4 0.7 1.7 4.9 8.4 1.8 0.8 14.1 32.4 6.27
8 5.3 2.6 3.2 3.7 4.6 4.2 3.6 2.7 24.6 0.4 2.3 1.3 5.9 1.3 0 4.4 15.6 2.90
Check 5.0 3.9 2.8 5.2 6.6 4.8 4.3 3.2 30.8 0.2 1.5 1.4 1.3 0.4 1.1 7.2 13.1 2.50

*Pounds of fertilizer applied per tree annually: 1925, 15; 1926, 20; 1927, 25; 1928 & 29, 30; 1930 & 31, 40; check, nothing.
** pH of composite sample of soil at start of experiment, 6.7.







Fertilizer Experiments With Pecans


annually. During the same years the annual production of the
unfertilized Curtis averaged 0.13 pounds and the Success 2.5
pounds per tree. This average yield would show an increased
annual production over the checks when calculated on the basis
of 17 trees per acre of more than 270 pounds for the Curtis,
Plots 1 and 3; and 130.3 pounds for Success, Plot 2.

TABLE 9.-EFFECTS OF DIFFERENT NUMBERS OF FERTILIZER APPLICATIONS
ON THE SIZE AND COMPOSITION OF PECAN NUTS*.
Size of Nuts || Percent Kernel and Analyses
Plot No. -No. Diam. Length 1 Percent Percent Percent Percent Percent
per Ib. 16th in. 16th in. 1 Kernel HO Fat Protein Ash
CURTIS


1

2

3

4

5

6

7
8

Check



1

2

3

4

5

6

7

8

Check


24 57.98

24 58.92

25 58.07

24 58.53

25 58.06

25 57.23

25 56.46

23 57.77

23 57.97
SUCCESS


58 16 23

61 16 23

62 16 23
61 15 23

59 16 23

61 16 23

56 16 23

64 16 22

51 16 23


55.12

55.14

55.44

54.54

54.76

55.58

55.38

56.26

53.57


72.36

72.01

72.05

70.80

71.09

70.19

72.07
70.32

70.73



69.79

69.55

69.31

68.47
68.46

68.30

69.15

67.69

70.78


9.62

9.69

9.99

10.80

10.87

11.15

9.26
11.41

12.51



11.81

12.39

12.77

13.39

12.32

13.13

12.53

13.82

12.14


1.69

1.76

1.72

1.80

1.82

1.97

1.88
1.90

1.75



1.91

1.91

1.99

2.09

2.12

2.06,

2.08

2.30

1.81


*Averages for 6 years
5 and 4 years respectively.


except Success plots 8 and Check


which are for


Table 9 gives the analysis of the Success and Curtis produced
in this experiment. Apparently varying the number of appli-






Florida Agricultural Experiment Station


cations of complete fertilizer or ammonia applied in several
applications had no effect on the composition of the nuts.

SULPHATE OF POTASH AND MURIATE OF POTASH
COMPARED
Sulphate of potash and muriate of potash as sources of potash
were tested in orchards located in Jefferson County on Norfolk
fine sandy loam soil. The varieties used were Moneymaker and
Moore set in 1919, and Schley set in 1910. The tests on the
Schley trees were conducted from 1924 to 1929, while with the
Moneymaker and Moore they were made from 1928 to 1931. The
pH of the soil and the orchard results are shown in Table 10.
MONEYMAKER
There were four plots of the Moneymaker variety containing
six trees each. Three of these were fertilized and one was left
unfertilized as a check, the fertilizer varying only in the source
or percent of potash. Plots 11 and 12 received 4-8-6 and 4-8-8
mixtures, respectively, in which the potash was supplied in
muriate of potash, and Plot 9 was fertilized with a 4-8-6 in
which the potash was derived from sulphate of potash. The
trees were located on Norfolk fine sandy loam soil in Jefferson
County and were nine years old when the experiment was started
in 1928 (Table 10).
Growth.-The greatest growth was made by the Moneymaker
trees in Plot 9 where the potash source was sulphate of potash,
but the trees in all fertilized plots made a much greater growth
than where no fertilizers were applied.
Yield.-Plots 11 and 9, which contained the highest yielding
trees of all, were fertilized with a 4-8-6 mixture in which the
potash sources were muriate and sulphate of potash, respectively.
The yield in these two plots averaged 28.77 and 28.67 pounds per
tree annually, respectively, while the checks produced 9.32
pounds per tree, or an increase of over 200 percent. The yields
obtained in Plots 9 and 11 would thus show an increase in pro-
duction of a little more than 323 pounds average annually per
acre of 17 trees above that where no fertilizers were applied.
MOORE
The comparative effects of sulphate and muriate of potash
on the growth and yield of the Moore variety were studied in
the same orchard in Jefferson County in which the Moneymaker








TABLE 10.-COMPARATIVE EFFECTS OF SULPHATE AND MURIATE OF POTASH ON GROWTH AND YIELD OF PECANS.


Plot pH of Soil
No.* 0-9 Inches
1932**


Growth Increment Per Tree
Area of Trunk Cross Section in Square Inches Yield Per Tree in Poun s

1924 1925 1926 F 1927 1927 9 sT 1930 1931 I Total 1924 1925 1926 [ 19'7 1928 1 920 1930o 19 1


Total | Avg-. Annual


MOORE-Trees Set 1919!**

S ................. 11.2 19.5 14.0 6.8 51.5

S13.8 18.7 15.3 6.1 53.9

....... 13.3 18.0 12.7 6.2 50.2

S..6.9 10.9 8.0 4.3 30.1

MONEYMAKER-Trees Set 191I'*

S........... 124 15.1 12.8 5.4 45.7

.... 11.5 12.9 9.5 5.3 39.2
S .. ..... 10.4 10.3 8.0 4.6 33.3

....... 8.0 8.9 5.9 3.1 25.9

SCHLEY-Trees Set 1910****


9
11

12

Check




9

11

12

Check




5

7

6


9.1 15.3

6.5 10.6

3.2 9.6


41.8 1.7 11.4 61.8 119.7

39.5 2.7 16.3 73.1 131.6

31.7 2.7 167 69.1 120.2

6.1 1.2 4.3 31.7 43.3




15.8 2.3 2.9 93.7 111.7

22 2 0.2 6.5 86.2 115.1

18.1 1.9 2.1 69.5 91.6

2.5 0.1 1.1 33.6 37.3


7.5 5.9

11.3 6.6
7.1 2.0


8 5.8 4.2 7.6 7.3 8.1 5.5 S.2 40.9 0.9 19. 0.1 10.4 3.2
Cheek 6.0 6.2 I 6.5 8.7 6.7 12.5 9.3 499 7.0 28.8 0.9 23,6 7.7
Check 6.0 6,2 9 8

*Pounds of fertilizer applied per tree annually:
Moneymaker & Moore, 25 lbs. 1928-31, inclusive; Schley, 50 lbs. 1924-25; 75 )bs. 1926-1929, inclua;Nc.
** pH of composite sample of soil at s:art of experiment, Moneymaker & Moore 6 2; Schley 7.0.
*** Experiment started in 1928. All trees except checks fertilized in previous years by grower.
**** Discontinued in 1929.


108.9'

. 9.S

53.5 I

36.0

70.1


1.9

2.1


9.7
8.1

7.,1







Florida Agricultural Experiment Station


was located. The trees were set in 1919 on Norfolk fine sandy
loam soil and were nine years old when the experiment was
started in 1928. There were four plots of six trees each, three
of which were fertilized, one being left unfertilized as a check;
the only difference in the fertilizer being in the source and per-
cent of potash. Plots 11 and 12 were fertilized with 4-8-6 and
4-8-8 mixtures containing muriate of potash, while Plot 9 re-
ceived a 4-8-6 in which sulphate of potash supplied the potash
(Table 10).
Growth.-The trees of the Moore variety that made the most
growth were those in Plot 11 which were fertilized with a 4-8-6
mixture in which the potash was derived from muriate of potash,
and the second highest growth was made by the trees that were
fertilized with a sulphate of potash mixture of the same formula.
All fertilized trees, however, made a much more substantial
gain in growth than was made by the unfertilized checks.
Yield.-There was no great difference in the total yield per
tree of those fertilized with either a 4-8-6 or 4-8-8 mixture con-
taining either muriate or sulphate of potash. The highest yield-
ing trees were those in Plot 11 where a 4-8-6 muriate of potash
fertilizer was used, but all of the fertilized trees produced a
much higher yield than did those that were unfertilized. The
average annual yield per tree for this plot was 32.9 pounds,
while for the trees in the second high plot (number 12), amount-
ed to 30.05 pounds, and that for the unfertilized plot averaged
only 10.82 pounds. The increase in yield of the fertilized plots
was approximately 200 percent. On this basis the increased
production of the trees in Plot 11 would amount to 375.3 pounds
average annually per acre of 17 trees.

SCHLEY
The Schley orchard in which the sources of potash tests were
conducted was located in Jefferson County on Norfolk fine sandy
loam soil. The trees were set in 1910 and the experiment started
in 1924 when the trees were 14 years old. That part of the
orchard included in the experiment was divided into five plots,
four of which were fertilized and one maintained as a check in
which nothing was applied. The fertilized plots contained five
trees each and the check eight. Plots 5 and 7 received appli-
cations of 4-8-4 and 4-8-8 mixtures in which the potash was
supplied in sulphate of potash, while Plots 6 and 8 received the
same formulas, but the potash was derived from muriate of







Fertilizer Experiments With Pecans


potash. The only variations in the fertilizers were in the source
and percentage of potash (Table 10).
Growth.-The Schley trees making the greatest amount of
growth were those fertilized with a 4-8-4 and a 4-8-8 in which
the potash was supplied as sulphate of potash. The other two
plots receiving the same analyses and amounts of fertilizer with
the potash derived from muriate instead of sulphate of potash,
made less growth per tree than the unfertilized plot.
Yield.-The production of nuts in the different plots was in
the same order as growth increment, with Plots 6 and 8 giving
lower yields than the unfertilized plot. The average annual
yield in pounds per tree amounted to 18.11, and 16.46 for Plots
5 and 7, respectively, while for the check it was 11.68 pounds.
TABLE 11.-EFFECT OF SOURCE OF POTASH ON SIZE AND COMPOSITION OF
PECAN NUTS*.
Size of Nuts I Percent Kernel and Analyses
Plot No. Diam. Lnith Perc t Peent nt Pe ler nt rcr Percent Percent
No. per Ib. 16th in. 16th in. Kernel H1O Fat Protein Ash
MONEYMAKER

9 66 15 21 46.34 4.15 67.22 9.35 1.67
11 68 15 21 44.47 4.11 66.90 9.54 1.69
12 67 15 21 43.63 4.05 66.84 9.03 1.61
Check 68 15 21 45.56 3.87 68.56 10.97 1.75

MOORE

9 83 12 23 48.20 3.61 71.68 9.83 1.54
11 88 13 24 46.71 3.40 70.47 9.52 1.56
12 90 12 23 47.45 3.64 71.06 8.98 1.54
Check 88 13 23 45.42 3.80 69.31 10.69 1.52

Averages for four years.
** Source of potash: Plot 9, sulphate of potash; Plots 11 and 12, muriate
of potash.

Table 11 gives the analysis of Moneymaker and Moore nuts
produced in the experiment in which muriate and sulphate of
potash were compared. No outstanding differences due to the
source of potash were found, and increasing the potash from 6
to 8 percent in the mixture did not seem to affect materially the
composition of the nuts.







Florida Agricultural Experiment Station


POTASH AND NO POTASH COMPARED
The influence of potash on growth and yield of Moneymaker
and Moore pecans was studied in two orchards located in Jeffer-
son County in which fertilizer mixtures with and without potash
were applied. The experiment was started in 1924 with the
Moore and in 1926 with the Moneymaker, and continued until
1931. The trees were set in 1912, the Moore on Norfolk fine
sandy loam and the Moneymaker on Norfolk fine sandy soils,
and were fairly well developed for their ages at the beginning
of the experiments. The soils of both orchards were given ordi-
nary care which included the growing and returning of several
cover crops during the time the work was under way, and the
Moore trees were sprayed during some of the years to control
insects.
The trees of each variety were divided into four plots, three
of which were fertilized and one left unfertilized as a check.
The Moneymaker plots contained three trees each except the
check plot which included two, while the plots in the Moore
orchard were made up of five trees each. The fertilizer formulas
applied in the treated plots were: Plot 1, 4-8-0; 2, 4-8-4; 3, 4-8-8;
the sources of ammonia in all mixtures were sulphate of am-
monia, blood, and cottonseed meal. Therefore, the only differ-
ence was in the potash which varied from none to 4 and 8 per-
cent. Detailed information as to soil and fertilizer and the tree
growth and yield are given in Table 12.

MOORE
Growth.-The growth of the Moore trees as shown in Table
12 was consistently greater in the fertilized plots than where
no fertilizers were applied except in 1924 and 1931, when the
checks out-grew one of the treated plots. The plots where com-
plete fertilizers were used produced the greatest amount of total
wood growth, the no potash second, and the checks, third. The
general condition of the fertilized trees throughout each growing
season was decidedly better than that of those unfertilized, as
determined by the vigorous twig growth and the dark green
color of the foliage. (Fig. 4.)
Yield.-When the data given in Table 12 are considered, it
would seem that potash had some influence on the yield of the
Moore trees in this experiment, as the plots where complete
fertilizers containing 4 and 8 percent potash were applied pro-






Fertilizer Experiments With Pecans


duced a much higher yield of nuts
phosphoric acid only were applied.


than where ammonia and


Fig. 4.-The Moore orchard in Jefferson County in which the potash
tests were conducted. Tree A fertilized; B unfertilized.

The increased production of nuts by plots when calculated on
an acre basis of 17 trees shows a little more clearly what the
different yields would mean in an orchard. The trees fertilized
show an average annual increase over the checks in pounds per
acre of 92.9 for the 4-8-0 mixture, 238.5 for the 4-8-4, and 195.7
for the 4-8-8.
MONEYMAKER
Growth.-All trees in the fertilized Moneymaker plots made
a much greater total growth than those unfertilized, but they
did not follow in the same order of fertilizer treatments as was
true with the Moore. The plot in which the trees made the
greatest amount of wood growth was No. 1, in which no potash
was used in the fertilizer mixture.
Yield.-The differences in yield of the Moneymaker trees in
the various plots were not in the same order as those in the
Moore orchard, although the highest yielding plot was the one
in which a 4-8-8 fertilizer was applied, the second highest was
Plot 1, in which ammonia and phosphoric acid only were applied,
with Plot 2, in which the trees received a 4-8-4 fertilizer, third,















TABLE 12.-EFFECTS OF POTASH ON GROWTH AND YIELD OF PECANS.


Plot pH of Soil Growth Increment Per Tree Yield Per Tree i
No. p0-9 Inc Area of Trunk Cross Section in Square Inches
No.1924 0-9 Inches 6 1 192 192 1
)1932"* I 9r21925;r 19261 1927199M2f 1 929 19301 19317 Total ii 19241 19257 1926 1927 19281 1929 1


n Pounds


30 1931 Total ) Avg. Annual


MOORE-Trees Set 1912


1 5.1 4.7 6.3 9.5 4.5 11.9 8.8 9.6 5.0 60.3 0.1 52.9 2.2 13.1 33.2 1.3 18.4 30.7 151.9 18.99

2 5.4 2.0 6.5 10.8 6.9 12.9 7.0 12.6 5.9 64.6 0.1 49.9 9.1 22.4 66.8 0.2 26.5 45.4 220.4 27.55

3 5.0 4.1 7.8 12.3 5.7 12.6 8.1 10.2 3.3 64.1 0.1 52.2 6.8 9.8 68.4 0.0 15.7 47.3 200.3 25.03

Check 5.6 2.4 3.7 6.0 3.9 6.8 6.3 4.7 4.0 37.8 0.1 43.5 1.1 6.8 24.0 1.2 7.9 23.6 108.2 13.52

MONEYMAKER***-Trees Set 1912


1 5.8 ... .. 10.8 10.2 15.3 21.7 16.5 7.0

2 5.8 ... 7.4 10.4 12.0 17.5 8.7 6.0

3 6.3 8.2 9.7 14.8 19.7 15.0 7.4

Check 6.1 .......... .......... 8.8 5.9 11.1 17.3 10.2 5.0


3.8 134.2 0.2 87.0 2.7 102.0 329.9 54.98

3.0 116.3 0.4 75.3 0.3 85.6 280.9 46.81

1.8 110.4 3.5 71.5 7.5 150.8 345.5 57.58
2.7 65.3 3.8 33.0 2.5 74.5 181.8 30.30


*Pounds of fertilizer applied per tree annually:
Moore, 50 lbs. per tree, 1924 & 25; 75 lbs. per tree 1926-31 inclusive.
Moneymaker, 50 lbs. per tree, 1926 & 27; 75 lbs. per tree 1928-31 inclusive.
**pH of composite sample of soil at start of experiment: Moore, 6.8; Moneymaker. 6.2.
*** Experiment begun in 1926.


------







Fertilizer Experiments With Pecans


while the unfertilized trees produced the lowest yield of all.
Therefore, the results in this orchard did not indicate that
potash had any consistent appreciable effect on increasing the
production of nuts. However, the results do show that there
were seemingly appreciable increases in the yield of the entire
fertilized block of trees over the unfertilized as the lowest yield-
ing fertilized plot produced 16.5 pounds more nuts per tree an-
nually than where no fertilizers were applied.
If the yield data given in Table 12 are calculated per acre of
17 trees, the production possibilities of well nourished trees of
this variety may be established. On this basis, Plot 3 would
show an average annual increased yield per acre of 463.7 pounds,
Plot 1, 419.5, and Plot 2, 280.6, which, regardless of the fertilizers
applied, seem to be significant.
TABLE 13.-EFFECTS OF POTASH ON SIZE AND COMPOSITION OF PECAN NUTS*.
Plot Size of Nuts __ Percent Kernel and Analyses
t No. Diam. 1 Length Percent Percent Percent Percent Percent
NO.** per lb. 16th in. 16'h in. Kernel H-O Fat Protein Ash
MOORE

1 75 13 24 48.04 4.22 69.66 11.44 1.66
2 74 13 24 47.82 3.78 69.66 11.33 1.59
3 78 13 24 48.34 3.94 70.45 10.98 1.63
Check 76 13 24 47.54 3.49 71.56 10.65 j1.50
MONEYMAKER

1 67 15 21 45.72 3.79 68.34 10.49 1.73
2 68 15 21 45.78 3.73 68.26 10.63 1.70
3 67 15 21 46.00 3.73 69.25 10.14 1.68
Check 65 15 21 47.85 3.53 69.60 10.79 1.56
Average for 6 years.
** Fertilizer formulas by plots: 1, 4-8-0; 2, 4-8-4; 3, 4-8-8; check, nothing.

Table 13 gives the analyses of Moneymaker and Moore pro-
duced in the plots where potash and no potash fertilizers were
compared. In both varieties the check or no fertilizer plot
produced nuts that contained the highest percentage of fats,
while the high potash fertilizer was second, which would indi-
cate that apparently the plant food normally in the soil was so
balanced as to produce nuts of high fat content without fer-
tilizers, even though the quantity of nuts produced on such trees






Florida Agricultural Experiment Station


was low. A fertilizer with a high potash ratio seemed to produce
a nut with a high fat content, while one with low or no potash
seemed to increase the protein content at the expense of the fat,
especially with the Moore variety.

COMPARISON OF DIFFERENT AMMONIA SOURCES
An experiment was run to determine what effect ammonia
from different sources might have on growth and yield of pecans.
The varieties used were Moneymaker, Moore, Schley and Stuart,
growing in Jefferson, Walton, Holmes and Escambia counties.
The trees of each variety were divided into 11 plots, 10 of which
were fertilized, and one left unfertilized as a check. The Money-
maker and Moore plots contained six trees each while the Schley
and Stuart included five. Nine of the plots received applications
of a 4-8-6 mixture in which the ammonia sources were varied
while on the tenth plot was used a 6-8-4 fertilizer in which the
ammonia was supplied by the same materials as in Plot 9. Nor-
folk fine sandy loam, Norfolk sand, and Norfolk fine sand were
the soils represented in these experiments. The Moneymaker
and Moore trees in Jefferson County and the Schley in Walton
County were set in 1919, the Schley in Escambia County in 1917,
and the Stuart in Holmes County in 1916. All trees had made
an average growth for their ages at the time the experiment
was started in 1924.
The ammonia sources used were nitrate of soda, sulphate of
ammonia, blood, and cottonseed meal, singly and in combination.
The ammonia in the fertilizers applied to the different plots was
supplied as follows: 1, cottonseed meal; 2, blood; 3, sulphate
of ammonia; 4, nitrate of soda; 5 and 7, sulphate of ammonia
and cottonseed meal; 6 and 8, sulphate of ammonia and blood;
9 and 10, sulphate of ammonia, blood and cottonseed meal.
General information as to locations, varieties, soils, etc., and
the results in tree growth and yield are given in Table 14. The
discussion of the results will be included under each variety
heading, as well as by location of the orchard in which the ex-
periment was conducted.
MONEYMAKER
The orchard in which the Moneymaker trees were growing
was located in Jefferson County on fine sandy loam soil and was
reasonably well cared for during the time the experiment was
under way. Except for the first two years when corn and velvet







Fertilizer Experiments With Pecans


beans were grown between the tree rows, a cover crop of beggar-
weed was grown and returned to the soil annually.
A soil condition that was not conducive to pecan tree growth
existed over parts of Plots 3, 4, 5, and 6, but its effect on the
trees was not detected until the experiment had been running
for several years. Some of the trees in this area rosetted to
such an extent that they did not make the growth and yield
made by other trees similarly treated. The ammonia sources
used in the fertilizers applied to the trees in these plots were:
Su phate of ammonia, nitrate of soda, sulphate of ammonia and
cottonseed meal, and sulphate of ammonia and blood. The soil
condition referred to above was doubtless responsible for the
poor showing made by the fertilized trees in these plots.
Growth.-The trees in all fertilized plots made a larger growth
than the checks, except those in Plots 4 and 5, the first supplied
with ammonia from nitrate of soda and the second from half
cottonseed meal and half sulphate of ammonia. It should be
pointed out, however, that parts of these two plots occupied the
area where the soil condition was such that rosette developed in
the trees, which doubtless caused the poor growth as indicated
by the annual measurements of the trees. That the fertilizer
treatments were not responsible is indicated by the fact that
the differences were not consistent with the results in other
plots.
The greatest growth was made by the trees in Plot 9, which
received ammonia from sulphate of ammonia, blood, and cotton-
seed meal in the ratio of 1/ inorganic and 3 organic. Plot 8
produced the second highest amount of wood growth with the
ammonia sources in the same ratio but supplied by 1/ sulphate
of ammonia and % blood; while the trees in Plot 10 which were
fertilized with a 6-8-4 mixture, in which the ammonia sources
were the same as 9, made the third highest growth.
Under the conditions of the soil where this part of the experi-
ment was conducted, there was seemingly no consistent differ-
ence in the amount of wood growth developed by the Money-
maker trees fertilized with various sources or combinations of
sources of ammonia. The results indicated, however, that ade-
quate fertilization will produce a satisfactory growth in trees
of this variety when other factors are favorable.
Yield.-The Moneymaker trees began yielding light crops in
1925, but the bulk of the nuts was produced from 1927 to 1931,
inclusive, or the ninth to the thirteenth years after they were








TABLE 14.-EFFECT OF DIFFERENT SOURCES OF AMMONIA ON GROWTH AND YIELD OF PECANS.


Growth Increment Per Tree


0-9 Inches Area of Trunk Cross Section in Square Inches
0-9 Inchesn i 1
1932** 192 .19 26 1926 1927 1928i 1929 190 1931 I


Yield Per Tree in Pounds

total 1924 1925 1926 ] 1927 1928 I 1929 | 1930 j 1981 Total !Avg. Annual***


MONEYMAKER-Trees Set 1919


Plot
No.*




1

3
4
5
6
7
8
9
10
Check



1
2
3
4
5
6
7
8
9
10
Check



1
2
3
4
5
6
7
8
9
10
Check


9.6 10.0
8.3 10.6
10.6 13.0
7.6 8.9
7.8 9.3
9.8 12.6
11.0 11.1
12.4 14.2
12.4 15.1
12.2 13.7
8 0 8.9


4.0 5.1 8.7 10.4 10.2 11.3
5.0 6.7 11.9 8.2 8.6 11.6
4.4 6.1 8.7 10.4 8.7 12.6
6.4 9.3 7.7 14.7 8.7 13.4
5.6 8.0 8.9 13.5 9.3 15.0
7.4 6.9 7.5 11.4 10.2 16.5
6.1 7.9 9.4 11.7 10.5 15.8
4.5 5.5 8.5 7.4 9.4 16.3
9.1 9.4 12.0 16.8 11.1 19.5
6.4 12.0 9.8 19.6 15.2 21.4
4.7 7.6 5.4 10.6 6.9 10.9


32 55.1 0 0
3.9 53.4 0 0.01
3.9 69.8 0 0.01
3.2 46.4 0.1 1.9
2.0 47.3 0 0.2
4.7 64.2 0 0.1
4.6 66.6 0 0.5
5.1 81.0 0 0.2
5.4 84.5 0.01 1.5
1.8 75.5 0.02 2.7
.I1 53.2 0 0.5

MOORE-Trees Set 1919

4.5 63.6 0.1 4.0
3.1 62.7 0.2 6.0
3.7 64.4 0.1 8 6
5.5 77.0 0.01 3.4
4.3 76.1 0.1 2.6
5.3 76.4 0 2.1
4.2 76.4 0.04 6.3
5.5 69.6 0.02 4.5
6.8 99.0 0.1 8.6
6.6 106.0 0.1 12.5
4.3 58.4 0.01 1.6


0.1 10.4 1.0
0.1 3.0 4.1
0.9 10.2 2.1
1.8 3.9 4.8
0.8 7.7 1.4
0.7 8.4 6.2
3.2 17.5 4.0
2.1 14.8 9.1
4.5 13.3 15.8
5.0 11.6 16.1
0.8 7.1 2.5



1.4 5.7 26.5
1.6 13.3 23.5
2.3 13.2 23.0
3.2 6.1 15.0
2.0 4.5 22.7
2.5 10.9 14.5
4.9 15.4 27.2
7.3 6.4 22.3
5.1 12.1 41.8
11.6 17.3 50.0
1.4 5.5 6.1


SCHLEY--Trees Set 1917

3.6 1.6 3.7 2.2 3.5 3.7 3.4 3.9 25.6 0 0
4.5 2.9 5.0 4.1 5.0 3.3 5.2 6.0 36.0 0 0
5.9 2.3 4.0 3.7 4.1 5.0 3.8 5.4 34.2 0 0
3.8 3.0 5.5 2.3 4.6 4.9 3.2 4.8 32.1 0 0
5.3 3.0 7.7 3.6 5.2 5.9 4.5 4.5 39.7 0 0
4.3 3.5 4.1 3.9 4.8 3.5 4.8 6.0 34.9 0 0
5.4 2.9 4.7 3.5 4.8 6.2 5.1 6.6 39.2 0 0
6.6 4.4 4.4 3.2 5.5 6.5 4.4 5.1 40.4 0 0
2.4 2.7 6.2 3.6 4.5 7.1 3.7 4.2 34.4 0 0
6.7 3.1 3.9 4.3 5.6 5.4 4.8 .0 38.8 0 0
3.1 1.5 1.5 2.0 1.9 2.7 2.2 2.3 17.2 0 0


0 1.1 47.3 59.9
0 2.2 44.6 54.0
0 1.7 49.1 64.0
0.3 0.8 27.1 40.7
0.2 3.0 35.4 48.7
2.2 4.4 68.7 90.7
8.8 3.3 81.2 118.5
6.8 4.1 94.0 131.1
2.3 2.9 93.7 134.0
2.5 7.0 80.7 125.6
0.1 1.1 233.6 45.7


0 6.3 53.0 97.0 18.30
0 6.9 48.7 100.2 18.48
0.3 6.5 55.3 109.3 19.66
0 2.9 32.0 62.6 11.20
0 2.0 47.5 81.4 15.34
0.3 8.3 61.0 99.6 19.00
0.5 11.6 67.5 133.4 24.14
1.5 15.3 73.5 130.8 23.80
1,7 11.4 64.8 145.6 26.36
1.2 16.9 69.7 179.3 31.02
1.2 4.3 31.7 51.8 9.76


5.0 4.7 10.7
3.5 5.5 9.2
3.7 3.6 7.4
5.4 8.1 13.9
4.6 8.9 13.8
3.0 4.5 7.7
3.2 6.2 9.6
3.5 5.8 9.5
1.4 5.9 7.4
3.2 4.7 8.0
2.0 3.1 5.2


nH of Soil I


3.9 6.6 8.1 7.1
2.9 5.1 8.7 7.1
5.3 8.0 12.9 6.3
2.9 6.0 6.6 6.2
3.1 5.2 6.8 6.5
3.6 6.8 6.5 11.9
5.8 6.5 8.0 10.2
5.1 8.2 9.7 14.7
5.3 8.8 12.9 11.8
6.2 8.9 9.0 11.2
5.77 6.9 5.8 8.9







TABLE 14 (Continued).-EFFECT OF DIFFERENT SOURCES OF AMMONIA ON GROWTH AND YIELD OF PECANS.


pH of Soil Growth Increment Per Tree
p fIn Alea of Trunk Cross Section in Square Inches Yield Per Tree in Poun's
0-9 Inches |
1932** ] 192-1l.25l 1921) 19271 1, 128 1929 | 19301 1931 Total ]; 191241 1925] 1926B 1927 1 19281 19291 1930 11,911 Total [Av. Annual"**


Plot
No.*




1
2
3
4
5
6
7
8
9
10
Check



1
2
3
4
5
6
7
8
9
10
Check


6.7 8.3
6.5 7.2
5.1 6.6
6.1 7.0
6.9 7.3
5.5 6.0
7.8 7.6
8.9 9.8
7.9 9.3
6.7 7.5
5.2 6.0


SCHLEYI.

fi S 1-


Trees Set 1919

.3 0 0.2 0.2 0.5
.8 0.1 0.1 10.1 0
.0 0 0.2 1.2 0.2
.8 0 0.1 02 0.1
.1 0.1 O.S 0.1
.0 0 0.1 0.3 01
.8 0 2 0.5 0
.9 0 0 1 0.6 0
.2 0 0.2 1.1 0.1
.7 0 0.2 0.3 0.1
.5 0 0.2 0.5 0.2


20.2 21.1

2 27.1
20 2 201.
19.4 20.1
11.1; 12.1
10.8 11.5
15.7 116.
17.1 18.5
19.:3 1 .9
1:i. 11.2


STUART--Trees Set 1916


5.4 4.3 8.7 9.6 5.6 10.3 7.8
5.4 3.2 4.2 7.4 5. 7.4 8.4
5.4 4.7 5.8 6.9 4.7 6.2 5.2
5.6 5.1 5.8 6.5 6.5 8.5 6.9
5.2 2.1 5.0 6.6 3.4 7.7 6.2
4.1 3.7 5.6 9.6 5.6 6.2 5.1
5.0 4.6 5.8 9.0 9.8 10.8 7.6
4.9 6.2 4.6 10.4 4.6 10.1 8.2
5.3 4.5 7.4 6.8 10.2 8.4 7.5
5.2 3.4 6.4 8.6 10.1 10.4 7.0
5.2 3.7 6.1 7.8 4.3 9.0 5.1


21.2 0 I .9
10.0 0.: 1
7.8 0 1.>
14.9 0 7.9
4.4 0 5.3
9.2 0 2.10
21.8 0o 1.5
13.9 0 1.1
17.2 0 9.2
12.9 0 7.1
14.3 0.2 10.1


0.:3 35.8
0.1 42.0
0 1 2 .6;
0.1 30.1
0.1 20.5

0.1 20 1
0.1 22.2
0 32.s
0.1 :3 1
0.1 28.0


721.7

55.(i
30.7


42.0

57.1


Pounds of fertilizer applied per tree annually:
Moneymaker & Moore: 10 Ibs. per tree, 1924; 15 lbs. 1925; 20 lbs. 1926-27; 25 ls. 1928-31: inclusive.
Sehley-Escambia County: 15 lbs. per tree 1924; 20 lbs. 1925; 25 lbs. 1926-1927 ; 20 lis. 1928-19I1 inclusive.
Schley--Walton County: 10 lbs. per tree 1924; 15 lbs. 1925; 20 lhs. 1926-31 inclusive.
Stuart: 15 lbs. per tree, 1924; 20 lbs. 1925; 25 lbs. 1926-27; 30 lbs. 1928-31 inclusive.
** pH of composite sample of soil at start of experiments: Moneymaker and Moore, 6.2; Schley, (.0; Stuart, 6.1.
*** Years averaged, all inclusive; Moneymaker and Moore, 1927-31; Schley, Escambia Clonty. 1!):90 :1 ; Schley, Walton, 1931; Stuart, 192l;-31.
f Located in Escambia County.
$ Located in Walton County.


4.2 2.3 1.3 41.3
5.2 2.1 1.4 .5
4.9 1.9 1.4 4.3
50 2.7 2.5 4.4
5.2 2.6 2.8 4.9
5.0 1.9 1.3 4.1
5.2 1.5 1.7 5.1
5.4 2.3 2.3 4.5
4.2 2.8 3.2 5.3
5.0 2.3 2.5 4.6
5.2 2.7 2.1 3.2






Florida Agricultural Experiment Station


set. Therefore, the average annual yield was calculated for this
period. The yields given in Table 14, however, include all eight
years that this part of the experiment was conducted for com-
parison, except in the column showing the average annual per
tree.
All trees that were fertilized produced more nuts than those
unfertilized except in Plot 4, which occupied a part of the area
where more or less rosette developed as the result of a soil con-
dition that was unfavorable to pecan tree growth.
The highest yielding trees for the entire period were those in
Plots 9, 8, 10 and 7, which received applications of fertilizers
containing 14 inorganic and 3/ organic sources of ammonia.
Sulphate of ammonia was used in all four mixtures with blood
and cottonseed meal in 9 and 10, cottonseed meal in 7, and blood
in 8. For 1927 to 1931 inclusive, the average annual yield per
tree in pounds from Plots 9, 8, 10 and 7 amounted to 25.60, 25.76,
23.58 and 22.96, respectively, while for the check trees it was
8.88. When these results are calculated on an acre basis of 17
trees the average annual increase in pounds per acre for the
fertilized trees over the checks would amount to 284.2 in Plot 9;
286.9 in Plot 8; 249.9 in Plot 10, and 239.3 in Plot 7.
MOORE
That part of the experiment to test the effects of different
sources of ammonia on growth and yield of Moore pecans was
located in the same orchard. The trees, therefore, were given
the same care as that described for the Moneymaker. The soil
was Norfolk fine sandy loam and had a high productive ability,
except that area specified under the Moneymaker discussion
where the condition was such that rosette developed in some of
the trees, it being more pronounced in Plots 4 and 5 than in any
of the others. While the growth manifested in the trees in the
two plots last mentioned was fairly comparable with that made
on adjacent plots outside the area, the yields were much lower.
The trees were set in 1919 and were well developed for their age
at the time the work was started in 1924. (Table 14.) (Fig. 1.)
Growth.-The greatest growth was made by the trees in Plot
10, where the fertilizer used was a 6-8-4, in which the ammonia
sources were 1/ inorganic and 3 organic; sulphate of ammonia,
blood and cottonseed meal being the materials used in the mix-
ture (Table 14). The trees in Plot 9 produced the second high-
est amount of wood growth, a 4-8-6 fertilizer being used in which






Fertilizer Experiments With Pecans


the ammonia was supplied from the same materials and in the
same ratio. The trees in Plot 2 made the least growth of all
the fertilized plots, but the average was 4.3 square inches per
tree greater than that developed by the trees where nothing
was applied.
Yield.-The yields in this part of the experiment were good
after the Moore trees attained bearing age, and seemed to show
significant differences as a result of the fertilizers applied. Each
fertilized plot produced more nuts than where nothing was added,
and while the yields in Plots 4 and 5 were relatively low com-
pared with the others, the light yields were seemingly the result
of the soil condition and not of the fertilizer treatments.
The four highest yielding plots of the Moore variety for the
entire period were 10, 9, 7 and 8. The ammonia applied in all
of the four high plots came 14 from inorganic and /% from
organic sources. Sulphate of ammonia was used in the fertilizer
mixtures applied in all four plots, with blood and cottonseed
meal in Plots 10 and 9, cottonseed meal in Plot 7, and blood in
Plot 8.
If the yields are considered from 1927 to 1931 inclusive, or the
ninth to the thirteenth years after the trees were set, a some-
what better insight is obtained as to what Moore trees, similarly
located and adequately fertilized, will produce after they attain
bearing age. For the last five years of the experiment, Plots
10, 9, 7 and 8 gave an average annual yield of 31.02, 26.36, 24.44
and 23.80 pounds of nuts per tree, respectively, while the checks
produced 9.76 pounds. This would represent an average annual
increase in yield per acre, on the basis of 17 trees, of 361.4
pounds for Plot 10, 282.2 for Plot 9, 249.5 for Plot 7, and 238.7
for Plot 8.
SCHLEY
The sources of ammonia tests with the Schley variety were
conducted in two orchards, one of which was located in Escambia
and the other in Walton County. The trees in Escambia County
were set in 1917 on Norfolk sand, and those in Walton in 1919
on Norfolk fine sand. The trees were of comparable sizes with
those of similar ages in other orchards when the work was
started in 1924.
Peach trees were growing as interplants in the Walton County
orchard at the time the work was started but they were removed
before there was any interference with the growth of the pecan
trees. Some cultivation with very little cover-cropping was






Florida Agricultural Experiment Station


practiced in this orchard and an occasional spray application of
Bordeaux was made on the trees for scab control during two or
three years but not sufficient to give complete control of the
disease; therefore, many of the nuts were lost annually as a
result of scab infections.
Very little cultivation was given the soil in the Escambia
County orchard and no cover crops were grown that were re-
turned to the soil. During the first two years of the experiment
the trees were sprayed with Bordeaux to control pecan scab
but the trees at that time were not in production and the results
could not show up in the yield. (Table 14.)
Growth.-The Schley trees located in Escambia County on
Norfolk sand made a smaller growth increment than those in
Walton County on Norfolk fine sand. The greatest growth in
each orchard was made by the trees in the plots where the
ammonia was derived from both inorganic and organic sources;
the highest amount of wood growth in the Escambia County
orchard being produced in Plot 8 in which the trees were sup-
plied with a 4-8-6 mixture containing 1/4 inorganic and 3/ organic
ammonia, supplied in sulphate of ammonia and blood, while
Plot 9 produced the most growth in the Walton County orchard
where the fertilizer was of the same formula and ratio of am-
monia sources but in addition cottonseed meal was used as a
part of the organic. In all of the plots of the latter orchard,
except 3 and 6, there was more growth made by the trees in the
fertilized plots than in the one unfertilized during the time the
experiment was conducted.
Yield.-Both of the Schley orchards produced a few nuts each
year from the time the work was begun in 1924 but, due to
losses from insects and disease as well as other causes, it was
impossible to get complete annual production records except for
two years in Escambia County and one year in Walton County.
Therefore, the results are not indicative of what might be true
under more favorable conditions.
Plots 4 and 5 yielded the highest in the Escambia County
orchard in which the sources of ammonia were nitrate of soda
in 4, and cottonseed meal and blood in 5; while Plot 3, in which
sulphate of ammonia supplied all of the ammonia, produced the
most nuts in the Walton County orchard. In Escambia County
the yield of all the fertilized plots was higher than that of the
check, but in Walton County the yield per tree in Plots 6 and 7






Fertilizer Experiments With Pecans


was slightly less than for the check, but all other plots gave an
increase in yield where the fertilizers were applied.

STUART
That part of the experiment to test the effect of various
sources of ammonia on the growth and yield of Stuart pecan
trees was located in Holmes County. The trees were set in 1916
on Norfolk fine sandy soil, and were fairly well developed and
of reasonably uniform sizes when the work was started in 1924.
Only ordinary care was practiced in this orchard during the time
the experiment was conducted. General farming was carried on
between the tree rows which consisted of the growing of inter-
crops, such as corn or cotton with peanuts between the corn
rows, but no crops for soil improvement purposes were grown
except an occasional crop of velvet beans planted with the corn.
(Table 14.)
Growth.-The greatest growth increment was made by the
trees in Plot 10 that were fertilized with a 6-8-4 mixture in
which the ammonia was 1/ inorganic and 3/ organic derived
from sulphate of ammonia, blood and cottonseed meal, while
the trees in Plot 7 that were fertilized with a 4-8-6, in which
the ammonia sources were in the same ratio as in 10, but with-
out blood, developed only slightly less wood growth than did
those in Plot 10. The trees in all fertilized plots, except in 3
and 5, made greater growth than those in the one unfertilized.
Yie!d.-The yields of the Stuart trees in this experiment were
rather irregular and while there were some variations in the
plots that were fertilized with different sources of ammonia,
they were not sufficiently consistent to be of significant im-
portance. Plot 5, in which the ammonia sources were all organic
being supplied in cottonseed meal and blood, gave the lowest
yield, while the trees in Plot 7, where the ammonia was 1
inorganic and '% organic, derived from sulphate of ammonia
and blood, produced the greatest amount of nuts during the
period of the experiment. The second and third highest pro-
duction was made by the trees in Plots 1 and 2, respectively, in
which the ammonia source was all organic.
From 1926 to 1931 the trees in Plots 3, 5, 6, and 8, produced
lower yields than the checks. The mixtures used in these low
yielding plots contained both organic and inorganic sources of
ammonia, except Plot 3 in which the ammonia was all inorganic.
The variable results in this experiment seemed to be due to







Florida Agricultural Experiment Station


variations in soil conditions and possibly to the treatment of
the intercrop, rather than to the effects of the ammonia sources,
as they were not consistent in all plots.
TABLE 15.-EFFECTS OF DIFFERENT SOURCES OF AMMONIA ON SIZE AND
COMPOSITION OF PECAN NUTS.
I Size of Nuts 1 Percent Kernel and Analyses
Plot
Not* No. 1 Diam. Length 1l Percent Percent Percent Percent I Percent
NO.* per lb. 16th in. 16'h in Vrrnel H.-O Fat Proten I Ash
MOORE*

1 84 12 24 48.03 3.36 72.98 10.58 1.60
2 88 13 24 45.54 3.42 72.00 10.77 1.62
3 85 12 24 47.45 3.45 72.64 10.23 1.58
4 86 13 24 48.39 3.34 71.69 11.26 1.64
5 84 13 24 49.08 3.43 73.20 10.81 1.59
6 79 13 24 48.90 3.33 73.57 10.39 1.51
7 84 12 24 49.01 3.28 73.49 10.41 1.50
8 77 13 24 49.39 3.21 1 73.65 10.03 1.49
9 82 12 23 49.68 3.24 73.21 10.45 1.57
10 83 12 24 47.95 3.38 72.63 11.20 1.65
Check 85 12 24 46.89 3.28 71.95 11.26 1.60
MONEYMAKER*

1 65 15 20 45.26 3.35 71.09 9.90 1.58
2 66 15 20 44.62 3.60 69.51 10.30 1.65
3 65 15 21 44.40 3.95 69.69 10.48 1.72
4 66 15 21 44.81 3.71 68.87 11.46 1.70
5 67 15 21 44.84 3.71 68.98 10.99 1.71
6 66 15 21 45.24 3.54 70.82 9.99 1.58
7 66 15 21 45.21 3.74 68.85 10.22 1.68
8 65 15 21 46.29 3.66 68.89 10.26 1.70
9 65 15 21 46.12 3.78 69.29 9.88 1.67
10 66 15 21 45.64 3.76 69.25 9.81 1.71
Check 67 15 21 44.21 3.75 69.51 10.94 1.73
STUART***

1 54 15 24 47.80 3.33 70.80 10.88 1.57
2 54 15 24 48.40 3.58 71.30 10.50 1.55
3 55 15 24 46.94 3.45 69.08 12.52 1.69
4 56 15 24 46.96 3.21 70.54 11.10 1.57
5 56 15 24 48.05 3.48 69.73 12.16 1.71
6 58 15 24 46.41 3.67 68.98 13.60 1.80
7 54 15 24 47.65 3.34 72.24 9.65 1.63
8 56 15 24 47.29 3.45 70.73 11.36 1.67
9 55 15 24 46.48 3.21 70.76 11.54 1.64
10 55 15 24 46.87 3.64 71.00 11.16 1.65
Check 54 15 24 47.01 3.58 70.90 11.10 1.52
Average for 5 years.
** Sources of ammonia by plots for all varieties: 1, cottonseed meal;
2, blood; 3, sulphate of ammonia; 4, nitrate of soda; 5 and 7, sulphate of
ammonia and cottonseed meal; 6 and 8, sulphate of ammonia and blood;
9 and 10, sulphate of ammonia, blood and cottonseed meal.
*** Average for 4 years.

Table 15 gives the analysis of Moore, Moneymaker and Stuart
pecans produced in the tests comparing sources of ammonia.





Fertilizer Experiments With Pecans


Apparently no one source or combination of sources of ammonia
has had any effect on the composition of the nuts. In fact, the
check trees produced nuts of about the same composition as those
that received the complete fertilizers.

SOIL AMENDMENTS
The soil amendments studies were conducted in the orchard
where the sources of ammonia tests were made with trees of
the Moore variety in Jefferson County. The trees were set in
1919 on Norfolk fine sandy loam soil and were of comparable
sizes for their age at the time the tests were begun in 1929.
There were five plots consisting of six trees each, except that
there were four in 17, four of the plots being fertilized and one
left unfertilized as a check. The effect of manganese sulphate
and copper sulphate, separately and together, on growth and
yield was tested. They were used as amendments in a 4-8-6
fertilizer mixture, and one plot received applications without
either of the amendments. The location, plots, age and number
of trees, soil pH, and amount of fertilizers and amendments
applied per tree annually and the tree growth and yield are
given in Table 16. (Fig. 5.)




















Fig. 5.-Moore pecan trees fertilized with mixtures containing (A)
. copper sulphate and (B) manganese sulphate appear to be in equally vig-
orous condition.














TABLE 16.-EFFECTS OF COPPER SULPHATE AND MANGANESE SULPHATE ON GROWTH AND YIELD OF MOORE PECAN
TREES SET 1919.

pH of Soil Growth Increment Per Tree-Area of Trunk Cross Yield Per Tree in Pounds
Plot No.* 0-9 Inches Section in Square Inches
1932"* 1929 1930 1931 Total 1930 11 Total Avg. Annua
-

9 5.6 19.5 14.0 6.8 40.3 11.4 64.8 76.2 38.10

15 5.4 13.2 8.3 5.0 26.5 12.8 45.2 58.0 29.00

16 5.5 13.0 10.0 5.3 28.3 9.0 51.5 60.5 30.25

17 5.7 17.4 10.8 6.0 34.2 20.3 64.6 84.9 42.45

Check 6.0 10.9 8.0 4.3 23.2 4.3 31.7 36.0 18.00

Fertilizer applied 25 lbs. 4-8-6 per tree annually to all fertilized plots.
Amendments applied per tree annually:
Plot 9-Fertilizer only
Plot 15--V lb. copper sulphate
Plot 16--1/ lb. manganese sulphate
Plot 17-%1 lb. copper sulphate and 14 lb. manganese sulphate
** pH of composite soil sample at start of experiment 6.2.
All trees except checks were fertilized previous to beginning of experiment by grower.






Fertilizer Experiments With Pecans


Growth.-All trees fertilized with a mixture containing the
amendments made greater growth than the unfertilized checks,
but somewhat less growth than where no amendment was added
to the fertilizers. The trees second highest in growth were
those in the plot in which the trees received, in addition to the
fertilizers, 1/ pound each of manganese sulphate and copper
sulphate per tree.
Yield.-The highest yielding plot was the one in which both
manganese sulphate and copper sulphate were added to the
fertilizer, averaging 4.35 pounds per tree annually more than
the production where nothing was added to the fertilizer, and
24.45 pounds per tree annually higher than the yield for the
unfertilized checks. The trees in the manganese sulphate plot
were third high in point of nut production with those in the
copper sulphate plot fourth, while the check trees produced the
lowest yield of all.

SUMMARY AND DISCUSSION
Pecan varieties vary in productiveness and ability to adapt
themselves to different soils and various climatic conditions, as
well as in resistance to fungus diseases. When trees are located
on unsuited soils no amount of any kind or mixture of fertilizer
will give profitable returns; likewise, the same would be true
with light yielding varieties and trees on soils where the cultural
program is inadequate. The Schley, when grown in Florida, is
highly susceptible to pecan scab, a disease which caused heavy
losses and accounted for much of the poor showing of this
variety in the experiments. Insects also caused considerable
losses as they destroyed many nuts on all varieties during years
of severe infestations and were responsible for many of the very
low yields. The differences in production for several of the ex-
periments would doubtless have shown greater contrasts if losses
could have been avoided; therefore, all such factors should be
taken into consideration when studying the results of the tests.
The average annual increase in yield of the fertilized over
the unfertilized trees is shown in Table 17 for the heaviest pro-
ducing plot in each experiment, along with the amount of fer-
tilizer applied. An examination of these data for the high
yielding plots shows that for each pound of fertilizer applied
the trees produced an increased yield of from about two-tenths
to nine-tenths of a pound of nuts per year except with the
Frotscher and Stuart. Furthermore, a consideration of all tabu-









TABLE 17.-AVERAGE ANNUAL INCREASED YIELD OVER THE CHECKS OF THE TREES IN THE HIGHEST PRODUCING PLOT IN EACH
EXPERIMENT.$


Location by County Soil
Type



Location by County
Bradford .......................~............... CFSL*
Duval ............-.......... .. ...... BFSL**
Columbia ...........-...................... NSL***
Bradford ...................................... CFSL*
Jefferson .......... ......................... NFSt
Jefferson .......... ............ ....... .... NFSLftt
Jefferson ................... -....-......-.. NFSLtt
Leon .............................. ....... .... OSttf
Jefferson ...................................... NFSL-t
Jefferson ..................................... NFSLtt
Jefferson .................................... NFSLtI-
Jefferson .................................... NFSLft

Escambia ...................................... NStttt
W alton ..................... ...... ............. N FSt
Holmes ......................... .. ....... NFSt
D uval ....... -........ ................... BFSL**


Curtis
Curtis
Frotscher
Kennedy
Moneymaker
Moneymaker
Moneymaker
Moneymaker
Moore
Moore
Moore
Schley

Schley
Schley
Stuart
Success


1919
1920
1912
1920
1912
1919
1919
1913
1912
1919
1919
1910

1917
1919
1916
1920


Fertilizers
Pounds Applied
Per Tree
Formula Annually
Average


4-6-6 25
4-9-4 35
6-8-4 56
4-8-4 15
4-8-8 66
4-8-6 25
4-8-6 25
4-8-4 30
4-8-4 66
6-8-4 25
4-8-6 25
Sulphate 7
cf Potash
4-8-6 20
4-8-6 20
4-8-6 28
4-9-4 35


Avg. Annual
Increased Years
Yield Per Averaged
Tree in Inclusive
Pounds


11.90 1927-31
16.07 1928-31
1.99 1924-31
11.10 1924-31
27.28 1926-31
16.88 1927-31
19.45 1928-31


5.13
14.03
21.26
22.08
6.98

4.20
12.20
3.02
7.67


1924-31
1924-31
1927-31
1928-31
1924-29

1930-31
1931
1926-31
1928-31


Coxville fine sandy loam.
** Bladen fine sandy loam.
*** Norfolk sandy loam.
i Norfolk fine sand.
tt Norfolk fine sandy loam.
ttt Orangeburg sand.
ttft Norfolk sand.
$ This table includes only plots that received commercial fertilizer applications.


I






Fertilizer Experiments With Pecans


lated yields discloses that the returns per pound of fertilizer
were much greater for the last year in most of the experiments,
which would seem to indicate that the trees were being increas-
ingly benefited by the addition of plant foods to the soil.
The data presented throughout this bulletin show that, re-
gardless of the fertilizer used, 88 percent of the treatments
produced higher yields than where no applications at all were
made. Frotscher, Schley and Stuart generally did not respond
to the fertilizers as favorably as did the Curtis, Kennedy, Money-
maker, Moore and Success. However, the varieties last men-
tioned that showed the greatest response to the additions of
fertilizers are generally heavier bearers than those of the first
group. It would seem, therefore, that trees of the heavier-
producing types, growing on soils similar to those represented
and given reasonable care, should produce adequate yields of
nuts if well balanced, complete fertilizer mixtures are applied
annually, other factors being favorable.
There were no significant beneficial effects obtained by apply-
ing fertilizers several times during the year to Bladen fine sandy
loam soil on which Curtis and Success trees were growing. How-
ever, the results should not be considered as conclusive for all
soil types, as the rather light soils where ammonia leaches
readily might show a favorable response in tree growth and
yield if two fertilizer applications were made, one in February
or March before bud growth starts, and the other in June or
July. But it would seem that on the heavier soils, one applica-
tion of fertilizer two or three weeks before bud growth forces
in the spring would be sufficient to give adequate tree growth
and yield, except during years when there is a heavy crop of
nuts, then a second application of ammonia in June or July when
adequate soil moisture is available, might be helpful in causing
the trees to develop the nuts and produce a twig growth that
would yield nuts the following year.
In most of the experiments where ample growth was made,
as calculated by the area of the cross-section of the tree trunks,
there were comparable yields that were sufficiently higher than
where no fertilizers were used to indicate the value of pecan
fertilization. Such results in growth would seem to explain why
the trees in many orchards grow and produce relatively good
crops of nuts when the trees first come into bearing, but when
they reach the age and size to produce heavy crops, it is im-
possible for them to secure sufficient nutrients from the soil






Florida Agricultural Experiment Station


to maintain growth and nut production. Therefore, it is im-
portant that the soils be supplied with the necessary plant food
materials as well as favorable moisture conditions and other
contributing factors at all times during the growing season if
growth and yields are to be maintained as the trees grow older.
The highest yielding plot of those supplied with commercial
fertilizers in the Moneymaker experiment in Leon County on
Orangeburg sand was the one in which the trees were fertilized
with 30 pounds per tree annually of a 4-8-4 mixture. The trees
were approximately 30 inches in circumference. The high yields
would seem to indicate that such an amount of fertilizer would
be about right for trees of this variety, of about the same size
and age, growing on similar soils and given ordinary cultural
treatment. The fertilizers applied in other experiments where
satisfactory growth and yields were obtained were in about the
same ratio for comparable-sized trees as those applied in the
Leon County orchard. Therefore, it would seem that a fairly
accurate index as to the amount of fertilizer to apply would be
to measure the circumference of the trees about two feet from
the ground and apply one pound of fertilizer for each inch of
the tree trunk circumference. Thus, trees that were 25 inches
in circumference would each receive annually about 25 pounds of
fertilizer.
The data were seemingly rather conclusive in indicating that
adequate plant food materials must be supplied to pecan soils
if tree growth and quantity yields of nuts are to be produced,
but that the varieties must be of heavy bearing types to give
the most favorable returns, and moisture conditions must be
favorable.
Potash sources did not produce any varying results in growth
and yield that could be definitely tied up with an effect of either
of the potash sources tested; although the Schley trees that
were fertilized with mixtures in which potash was supplied in
sulphate of potash produced higher yields than those where
muriate of potash was used, there were no appreciable differences
with the Moore and Moneymaker varieties.
The tests indicated that Moore trees growing on sandy soils
similar to those under test should be fertilized with complete
mixtures, as the highest yields were obtained where the fer-
tilizers carried all three elements of plant food. Moneymaker,
however, did not show such consistent differences, although the
highest yielding trees were located in one of the plots that re-










TABLE 18.-MAXIMUM AND MINIMUM NUT SIZES AND PERCENTAGES BY VARIETY IN PECAN FERTILIZER EXPERIMENTS.


Size of Nuts

Varieties No. Per biaeter: Length Percent Kernel
PVar s found 16th Inch 16th Inch e t
High Low High Low: High Low High Low


fMoneymaker* 74 55 16

Moneymaker** 75 62 15

Successtt ..... 88 51 16

Kennedyt ......... 71 60 14

Curtist .......... 86 79 13

Curtistt ......... 102 82 13

Frotscher*** 58 40 15

Moore** -........ 100 69 13

Stuartttt ....... 68 46 15

Leon County
** Jefferson County
*** Columbia County


44.11

45.88

60.70

53.69

57.17

60.15

53.73

49.53

49.04


Percent Kernel and Analyses


Percent H.O

High Low


34.54

44.01

48.32

50.46

54.84

54.94

18.23

41.97

45.32


Percent Fat Percent Protein Percent Ash


High Low High

71.96 56.16 18.61

72.86 62.03 13.38


70.90

74.64

75.45

73.41

73.77

75.72

71.77


64.38

71.18

71.88

69.53

63.36

64.20

69.13


17.45

10.54

9.75

12.22

16.44

13.53

11.80


t Bradford County
tt Duval County
ttt Holmes County


Low High

9.42 2.40

8.32 2.80

10.91 2.34

8.42 1.66

8.44 1.50

9.02 2.02

10.05 2.27

9.32 2.06

8.89 1.68


Low

1.58

1.57

1.80

1.43

1.35

1.63

1.60

1.46

1.57






Florida Agricultural Experiment Station


ceived a complete fertilizer, the second highest production was
made by the trees in the plot where ammonia and phosphoric
acid only were applied.
Manganese and copper sulphate added to a 4-8-6 fertilizer as
amendments, separately and together, did not have an appreci-
able effect on the growth and yield of Moore pecan trees growing
on Norfolk fine sandy loam soil in Jefferson County.
If the results of the experiments discussed are used as indi-
cations of what fertilizers would produce the best growth and
highest yield in pecan trees, it would seem that a general fer-
tilizer would be one in which the ammonia could be derived from
several sources but that a good mixture would be one in which
there would be approximately 1/ to 1/ inorganic and 3/ to 1/2
organic ammonia sources, and the phosphoric acid and potash
from the commonly used sources such as superphosphate and
sulphate or muriate of potash, respectively.
Therefore, if the formulas are based on the ratios indicated
as suitable for pecans, a 1-2-1 would be represented in 4-8-4,
6-12-6, 8-16-8, 12-24-12, or 15-30-15 fertilizers, while a 2-2-1
would be obtained in 8-8-4, 10-10-5, 12-12-6, or 16-16-8 mixtures;
and 6-8-4, 9-12-6, 12-16-8, 15-20-10, 18-24-12, or 24-32-16 would
contain the plant foods in 3-4-2 ratio.
In deciding on the fertilizer formula that should be used on
pecan soils, one should take into consideration the type of soil
and the amounts and kinds of cover crops that are grown and
disked in since lower percentages of ammonia are generally
required when heavy growths of legumes are being returned
to the soil annually.
In purchasing ready mixed goods, it is almost always possible
to obtain approximately the formulas given above in the ordinary
mixed fertilizers that are placed on the market by the fertilizer
companies. However, if the materials are purchased separately
and mixed on the farm, any desired formula can be.prepared by
using the proper amounts of the different materials carrying
the elements required.
Considering the analysis of pecans from all of the experiments,
fertilizers did not materially affect the composition of the nuts.
Weather conditions played a more important part as was evi-
denced by the marked range of the various constituents from
year to year. Table 18 gives the average maximum and minimum
percentages of the various constituents during the time these
experiments were conducted and it will be noted that the number






Fertilizer Experiments With Pecans


of nuts required to make one pound varied considerably. In
four cases the smallest nuts had the lowest percentage of kernel
which indicated that the nuts had not properly filled out. In
three cases the diameter or length or both were smallest when
the number of nuts required to weigh one pound was largest,
indicating smaller nuts. Likewise, there was considerable varia-
tion in the fat, protein and ash contents. Moneymakers showed
the largest difference between maximum and minimum. In gen-
eral, a low fat content was associated with a high protein con-
tent. The reverse, namely, a high fat and low protein content,
was not so generally found.
Table 19 gives the average sizes and analyses of the various
varieties from all sections. It will be noted that Frotscher and
Stuart produced the largest nuts, while the Schley had the
highest percentage of meat and the Moneymaker the lowest.
The highest fat content was found in the Kennedy followed
closely by the Schley, while the latter variety had the lowest
protein content, with the Kennedy second and Curtis third, in
close order. There were only slight differences in the ash con-
tent of the different varieties tested except with the Success
and Frotscher nuts which were appreciably higher than the
others.
TABLE 19.-AVERAGE SIZES AND ANALYSES OF PECAN NUTS PRODUCED BY
THE VARIETIES USED IN THE FERTILIZER EXPERIMENTS.


Size of Nuts


Diam.
16th in.


65 15
55 15


Length
16th in.

21
24


82 15 I 25


I1 Percent Kernel and Analyses
1I Percent Percent Percent Percent Percent
SKernel H20 Fat Protein Ash

43.60 3.84 68.38 10.84 1.69
i 47.25 3.44 70.55 11.41 1.63
S57.84 3.28 72.83 9.81 1.56
S55.09 3.71 69.05 12.70 2.03
50.31 3.76 69.13 12.78 1.92
I 57.19 3.36 72.33 9.86 1.64
52.21 3.20 73.28 9.85 1.52
48.07 3.48 72.16 10.77 1.65
_i __ ___ ____ __


Varieties No.
per lb.
Moey


Money-
maker

Stuart
Schley
Success
Frotscher
Curtis
Kennedy
Moore






48 Florida Agricultural Experiment Station

ACKNOWLEDGMENTS

The authors wish to express their thanks to Dr. 0. C. Bryan,
who made the original pH determinations and classifications of
the soils on which the experiments were located; R. E. Nolen and
the late F. W. Walker, who assisted in keeping records in Jeffer-
son County; E. W. Cowan, H. L. Marshall, and H. W. Winsor, who
made the chemical analyses; and the growers who permitted the
use of their orchards and willingly cooperated in conducting the
experiments.

LIST OF REFERENCES

1. BLACKMON, G. H. and RUPRECHT, R. W. Report on pecan fertilizer
experiments being conducted by the Fla. Agr. Exp. Sta. Ga.-Fla.
Pecan Growers' Assn. Proc. 26: 14-23. 1932.
2. BRYAN, O. C. The Soils of Florida. Fla. Agr. Ext. Bul. 42. 1925.
3. CAMP, A. F. Report on horticultural investigations. Fla. Agr. Exp.
Sta. Rpt., 1928: 54-56.
4. CRANE, H. L. Terminal growth in relation to fruiting in pecans. Nat'l.
Pecan Assn. Bul. 29: 24-32. 1930.
5. FOWLER, E. D. A Report on pecan fertilizers for the southeastern
United States. Ga.-Fla. Pecan Gro. Assn. Proc. 25: 6-10. 1931.
6. HEIGES, S. B. Nut culture in the United States, Special Report. U. S.
D. A. Div. of Pomology, 59. 1896.
7. HUME, H. H. Pecan culture. Fla. Agr. Exp. Sta. Bul 54. 1900.
8. Second report on pecan culture. Fla. Agr. Exp. Sta. Bul.
85. 1906.
9. REED, H. S. Correlation between growth and fruit production of apri-
cots. Am. Soc. for Hort. Sci., 25: 247-249. 1928.
10. SKINNER, J. J. Influence of soil types on the yield and quality of
pecans. Jour. Am. Soc. Agron., 16: 1: 51-57. 1924.
11. -. Pecan soils and their fertilization. Nat'l. Pecan Gro. Assn.,
Proc. 25: 54-61. 1926.
12. SKINNER, J. J. Fertilizers for pecan soils. U. S. Dept. of Agriculture
Leaflet No. 71. 1930.
13. SKINNER, J. J., and RUPRECHT, R. W. Results of fertilizer experiments
with pecans in the Jacksonville section. Ga.-Fla. Pecan Gro. Assn.
Proc. 20: 24-31. 1926.
14. SKINNER, J. J., and ALBEN, A. O. Fertilizing the pecan. Nat'l. Pecan
Assn. Bul. 30: 26-29. 1931.
15. TAYLOR, R. W. Influence of fertilizer treatments on yield and quality
of pecans. Nat'l. Pecan Assn. Bul. 29: 18-20. 1930.




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