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Group Title: New Series Bulletin - State of Florida, Department of Agriculture ; no. 24
Title: Avocados in Florida
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00015009/00001
 Material Information
Title: Avocados in Florida
Series Title: Bulletin. New series
Physical Description: 39 p. : ill. ; 23 cm.
Language: English
Creator: Toy, L. R
Florida -- Dept. of Agriculture
University of Florida -- College of Agriculture
Publisher: State of Florida, Dept. of Agriculture
Place of Publication: Tallahassee <Fla.>
Publication Date: <1931>
 Subjects
Subject: Avocado -- Florida   ( lcsh )
Avocado -- Varieties -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographical references (p. 39).
Statement of Responsibility: by L. R. Toy.
General Note: Cover title.
General Note: "October, 1931."
General Note: "Prepared and published in co-operation with the College of Agriculture, University of Florida, Gainesville."
General Note: "Reprint".
 Record Information
Bibliographic ID: UF00015009
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 002452068
oclc - 41390185
notis - AMF7367

Table of Contents
    Cover
        Page 1
        Page 2
    Foreword
        Page 3
        Page 4
    Main
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
        Page 22
        Page 23
        Page 24
        Page 25
        Page 26
        Page 27
        Page 28
        Page 29
        Page 30
        Page 31
        Page 32
        Page 33
        Page 34
        Page 35
        Page 36
        Page 37
        Page 38
    Publications of value to the Florida avocado grower
        Page 39
Full Text




Bulletin No. 24


New Se


ries October, 1931


AVOCADOS

IN

FLORIDA

(Reprint)
By
L. R. TOY


HUME OaRY

JUL 13 1973

I.F.A.S. Univ. of Florida
19 ATmf QFTPTI- A
DEPARTMENT OF AGRICULTURE
NATHAN MAYO, Commissioner
TALLAHASSEE


Prepared and Published in Co-operation with the College of Ii
Agriculture, University of Florida, Gainesville.
iitr


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DEPARTMENT OF AGRICULTURE
Nathan Mayo, Commissioner of Agriculture..... Tallahassee





















FOREWORD
No man in Florida knows more about avocado culture than
Mr. W. J. Krome, of Homestead, Fla., who has made this bul-
letin possible. While Mr. Krome did not write the manuscript
himself, he was generous enough to allow one of his employees,
Mr. L. R. Toy, prepare the manuscript. And in addition, he
gave Mr. Toy access to his records on avocado culture, which
cover a period of some twenty-five years.
The data contained in this bulletin cover the subject of avo-
cados in Florida very thoroughly, and no doubt will be the
guide of avocado growers for some years to come.
JOHN M. SCOTT,
Agricultural Editor.










Avocados in Florida

By L. R. TOY

Prepared and Published in Co-operation with the College of Agriculture,
University of Florida, Gainesville

HE NAME "avocado" originated from the Aztec word
for this fruit, "ahuacall." It is the name used in publi-
cations of the United States Department of Agriculture
and by horticultural societies, and is preferred to the term
"alligator pear" so frequently used.
The native home of the avocado is on the mainland of trop-
ical America. It has been grown as a dooryard tree for hun-
dreds of years in parts of the tropics, where the fruit is highly
esteemed as a food.
Avocados are found growing in almost every country of
tropical America and in many parts of the eastern tropics.
Trees of the hardier Mexican race have fruited as far north as
Rome, Italy, and in this state at Gainesville. Plantings in
orchard form, however, are comparatively recent and these
are to be found mainly in the warmer sections of Florida and
California.
The avocado was first introduced into Florida in 1833 by
Henry Perrine, who sent trees from Mexico to his grant of
land near Miami. Little was done to establish an avocado in-
dustry in this State until 1900, when the first avocado nursery
was established at Miami by Mr. George B. Cellon. Several
groves Were planted in that vicinity shortly following this date
and numerous plantings, varying in size from a few acres to
200 acres, have since been made. A number of groves have
been planted in other sections of the State, notably in the Fort
Myers region and in the "Ridge" section of Central Florida.
Due to cold and insufficient knowledge of the soil requirements,
as well as to various other causes, most of these plantings have
proven unsuccessful.
The acreage planted to avocados in Dade County, however,
increased gradually until the real estate boom of 1925 forced
the price of land to such a high figure that most of the groves
were sold for subdivision purposes, and the trees destroyed
or neglected.
The hurricane of September, 1926, damaged many trees be-
yond repair. The crop of fruit on the trees was almost a total
loss and the following year's crop was a negligible quantity.









DEPARTMENT OF AGRICULTURE


Interest in avocado culture during this period was at a low
ebb. It was only through the foresight and persistence of a
few, pioneer growers that the industry was made to survive
and continue on a basis which made possible the rehabilitation
of neglected and damaged groves, and further expansion of
the industry.
During 1927 and 1928 there has been a decided revival of
interest in avocado culture in Florida. Many new plantings
have been made and old groves reconditioned. Today there are
about 1,800 acres of avocados planted in Dade County. Ap-
proximately 1,200 acres are in bearing and 600 acres non-
bearing.
RACES AND VARIETIES
The avocados cultivated in Florida are classified in three
races, the West Indian, the Guatemalan, and the Mexican.
Those of the first two are of the same species, Persea Ameri-
cana, while the Mexican race is classified as a separate species,
Persea drymifolia.

WEST INDIAN RACE
Varieties of this race predominate in the lowlands of the
American tropics. It is at present the principal commercial
race of Southern Florida. Of the three races of avocados, the
West Indian is the most susceptible to cold. As a general
rule trees more than one year old will not be damaged by a
temperature of 32 F. unless that temperature holds for a
longer period than two or three hours. When four or five
years old they will stand 26 or 27 F. without injury, except
to tender growth, but below that temperature there is likely to
be considerable damage.
West Indian varieties bloom from February to mid-April and
the fruit matures in the summer and fall. Under favorable
conditions a few fruits of some varieties will hang on until
well into January. The amount of rainfall influences the
season, unusually wet summers tending to hasten maturity.
The fruits range in size from eight ounces to over three
pounds. The surface is usually smooth, in shades of color
from greenish yellow to dark maroon. The leathery skin
which characterizes the fruit of this race is from 1/64 to 1/16
of an inch thick.
VARIETY
TRAPP.-This variety was originated on the place of Mr.
C. L. Trapp of Coconut Grove, Florida, and was first propa-
gated in 1901. It is the most widely planted variety in the










AVOCADOS IN FLORIDA 7


Fig. 1. Trapp variety, 4 years old (West Indian Race).









8 DEPARTMENT OF AGRICULTURE

State and one of the most productive. The tree is a compara-
tively weak grower and tends toward alternate bearing; i. e., a
very heavy crop one season is followed by a light crop the next.
The fruit is roundish-oblate in shape, pale green or yellow-
ish green, smooth-skinned, and of medium to large size, weigh-
ing from 10 to 24 ounces. The flesh of the ripe fruit is smooth,
rich golden-yellow, changing to pale green near the skin. It
is of a delicate, nutty flavor, suggesting that of walnuts.
The season of the Trapp is from September 1 to January
1. Occasionally a few fruits will hang on until the middle of
January, but the bulk of the crop matures in October and No-
vember. Dropping occurs to a greater extent with the Trapp
than with many other varieties, due possibly to the large size
of the fruit and the small, brittle stem.
The Trapp is the standard of quality by which all other
West Indian varieties are judged. It ships well and occupies
an enviable position in the avocado markets of the country.
WALDIN.-This variety is of later origin than the Trapp and
less extensively planted. It originated in the grove of Mr. B.
A. Waldin of Homestead, and was first propagated in 1916.
The tree is a vigorous grower, productive, and hardier than
most varieties of its race. The fruit is oblong, with a charac-
teristic offset at one side of the blossom end. The size varies
from medium to large, and the fruit weighs 12 to 24 ounces.
The flesh is pale yellow to greenish yellow and of a very rich
flavor, preferred by some to the Trapp.
The normal season of the Waldin is from October 15 to Jan-
uary 1. The main crop matures, however, in November, fol-
lowing the main crop of Trapps, and a planting of these two
varieties gives an ideal succession for market purposes. The
blooming period,. although of shorter duration, coincides with
that of the Trapp. If these two varieties be grown in the
same grove, there will be greater opportunity for cross-pollina-
tion, as they are reciprocating varieties, as regards flower
opening. Other advantages secured by growing together these,
or any other two varieties of similar characteristics, are the
economies effected in handling the grove. When interplanted
varieties differ in time of blooming and maturing their fruit,
and in spraying requirements, handling costs are higher.
POLLOCK.-The Pollock originated at Miami, Florida, about
1896, and was first propagated in 1901. The fruit is oblong to
pear-shaped. It is the largest of the West Indian varieties
grown on a commercial scale, mature fruits weighing 16 to 36
ounces, with occasional specimens weighing more than three
pounds. Like all fruits of its race, the skin is thin and smooth.
The flesh is rich yellow blending with green near the skin. It



















































Fig. 2. Grove of 4-year-old trees (Trapp variety).













































,. . . i '




Fig. 3. Grove of 12-year-old trees (Trapp variety).









AVOCADOS IN FLORIDA 11


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Fig. 4. Pollock Avocado (West Indian).


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I
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1411j:1

~~ 'LJ~








12 DEPARTMENT OF AGRICULTURE

is of excellent quality and commands attractive prices in the
markets, even though it matures from July 15 to September
15, when Florida and Cuban seedling fruit is plentiful. The
large size of the fruit may prove objectionable in the future,
as the demand for smaller sizes is increasing from year to year.
The tree is a strong rapid grower. It is less prolific than
either the Trapp or Waldin and is somewhat more susceptible
to cold. The Pollock in many instances is inclined to be a "shy-
bearer." Several growers have reported increased crops in-
duced by a separate application of sulphate of potash in Sep-
tember or October. More extensive experimentation along
this line is to be desired.
SIMMONDS.-This is one of several selected seedlings orig-
inating at the United States Plant Introduction Gardens, Mi-
ami, Florida. It is an offspring of the Pollock and matures its
fruit a few weeks later than its parent. The fruit is oblong-
oval in shape, smooth-skinned, and green to yellowish green in
color. The average weight is about 22 ounces. Its smaller size
makes it more desirable than the Pollock from a marketing
standpoint. The tree is less vigorous than the Pollock, but
more productive. The blooming season of the Simmonds coin-
cides with that of the Pollock. These two varieties are "recip-
rocating" in their daily flower opening, thus affording oppor-
tunity for cross-pollination.' It is therefore well to interplant
the two in alternating blocks of three or four rows each.
GUATEMALAN RACE
This race is native to the highlands of Guatemala and south-
ern Mexico. It is more cold-resistant than the West Indian,
withstanding a temperature of 23 F. with but slight injury
under normal conditions.
Several varieties of this race are grown commercially in
Florida, but on a smaller scale than the West Indian. Gua-
temalan varieties bloom somewhat later than West Indians,
although the blooming period of some varieties overlaps that
of the latter race. The fruit matures from October to June,
depending on the variety. It is in most cases rough-skinned.
The color ranges from pale green to dark purple. The skin is
thick and hard except in a few varieties.
Because of its hardiness, the Guatemalan race promises to
become of much commercial value in parts of Florida, subject
to temperatures too low for West Indian varieties.
VARIETIES
WAGNER.-Originating in California in 1908 as a seedling
of the Royal variety, the Wagner avocado has been tested in
Florida and in 1922 commercial plantings were made. The







AVOCADOS IN FLORIDA 13


wa
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Fig. 5. Taylor variety, 31/ years old (Guatemalan Race).


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Fig. 6. Taylor Avocado (Guatemalan).








AVOCADOS IN FLORIDA 15

tree is fairly vigorous and has proven more prolific than the
average Guatemalan variety in Florida. The fruit is round to
ovate with a green, slightly roughened skin. Its size, 8 to 14
ounces, is well suited for market purposes.
TAYLOR.-Propagation of the Taylor was begun in Florida
in 1914. It is a "sister" variety of the Wagner, both varieties
originating as seedlings of the Royal. The Taylor was first
grown at the U. S. Plant Introduction Garden at Miami, and
for a time was rather widely planted. This variety is more
productive than the average of its race. It is an upright grow-
er, which is an objectionable characteristic because of the
longer time required for spraying and picking the fruit. In
some localities the leaves turn brown at the tips, producing
what is known as "leaf-scorch" or "tip-burn." The cause of
this trouble is not known. It is characteristic of several vari-
eties and is very pronounced in the Taylor.
The fruit is pear-shaped, some specimens having a long
neck. It weighs 12 to 18 ounces, is dull green in color and has
a somewhat roughened skin. In quality and flavor the Taylor
is fair to good.
In Dade County the fruit matures from December 15 to
February 15. Being a winter-ripening variety, the Taylor
usually brings good prices, as comparatively few avocados are
on the market at that season.
TAFT.-This variety originated at Orange, California, in
1900, and was first propagated in 1912. The fruit is pear-
shaped, light green, and weighs from 14 to 24 ounces. Its
season of maturity in Florida is February and March. The
fat content of the mature fruit is approximately 18 per cent.
It is of excellent quality and fine flavor.
The tree, under Florida conditions, is a rather slow grower,
but makes a strong, spreading, well-shaped tree. A longer
time is required for the tree to come into production than for
most varieties, and while young it is inclined to be a shy-
bearer.
The Taft is said to have responded satisfactorily to heavy
applications of potash in the fall. Further tests along this line
are in progress and it is hoped that some method of fertiliza-
tion will be worked out which will result in heavier crops of
this excellent fruit.
LINDA.-Introduced into California from Guatemala and
later propagated in Florida, this variety has proven to be well
adapted to conditions on the lower East Coast. The tree is
an exceptionally strong and rapid grower and fruits well, com-
mencing to bear at an early age. The new growth is a rich
wine color and when the tree is in "flush" it is strikingly or-
namental.








16 DEPARTMENT OF AGRICULTURE

The fruit is large to very large, weighing from 20 to 40
ounces. In form it is oblate to elliptical, deep purple in color,
and rough-skinned. The average fat content is 12 per cent
and the flavor is excellent.
The Linda matures its fruit in Florida from January 15 to
March 15. It ships well and usually commands high prices as
a fancy fruit, but on account of its large size is not so well
adapted for general market purposes.
MACDONALD.-Originating in Hawaii, the Macdonald has
been introduced into Florida and thrives well here. The fruit
is small to medium in size, spherical, dark purple tending to-
ward black in color, with a thick, roughened rind. The aver-
age weight is 10 to 16 ounces and the flesh is rich and nutty
in flavor. The season of maturity is March and April.
EAGLE ROCK.-The fruit of this variety is round to ellipti-
cal, weighing from 22 to 32 ounces. The skin is green and
the flesh is of excellent flavor. The fruit ripens in Florida
from January to March. The tree is a vigorous grower and
fairly productive.
MEXICAN RACE
This is the hardiest of the three races of avocados. Many
Mexican varieties withstand fully as much frost as the orange.
The foliage is characterized by an anise-like odor. Fruits of
the different varieties vary in weight from 3 to 15 ounces, the
color ranging from green to purple, and the oil content is very
high. The skin of the fruit is thin, similar to that of the
apple. The season of maturity is from June to November in
Florida.
Up to the present no large plantings of Mexican varieties
have been made in Florida. Along the lower East Coast
where most of the avocados in Florida are grown, the West
Indian race it better adapted and since the period of ripening
is the same as that of the Mexican race, there has been no in-
centive to plant varieties of the latter. Some varieties of this
race may, however, prove of value to colder sections of the
State. Mexican-Guatemalan hybrids, such as the Lula, may
be of even greater value for those sections.
Little is known as to varieties suitable for planting in Flor-
ida. Several varieties have been fruited, the most desirable
being Puebla and Gottfried.
HYBRIDS
This group includes varieties which originated as the result
of cross-pollination of a variety of one race with one of another
race. All of these described below are chance seedlings which
show evidence of such mixed parentage.






















































Fig. 7. Northrop Avocado (Mexican).


_~








DEPARTMENT OF AGRICULTURE


GUATEMALAN-WEST INDIAN hybrids originating in Florida
appear to be well adapted here and are generally hardier than
their West Indian parent. Most hybrids of this type ripen
their fruit later than the West Indians, but earlier than Gua-
temalans. It is because of this fact that hybrid varieties are re-
ceiving considerable attention in Florida.
COLLINSON.-(W. I. x Guat.) This variety originated at the
U. S. Plant Introduction Garden, Miami, Florida, in 1915, as a
seedling of the Collins, a Guatemalan variety.
The Collinson is one of the most rapid growing and vigorous
varieties grown in the State. Both the tree and fruit are re-
sistant to scab. The fruit is dark, glossy green, smooth-
skinned and pear-shaped. The average fruit weighs about 20
ounces. It is of excellent quality and fine flavor. In South
Florida the fruit matures from December 1 to February 15.
The tree is fairly hardy. In several widely separated dis-
tricts it has suffered as little injury from low temperatures as
many of the Guatemalan varieties.
WINSLOWSON, OR ROLFS.-(W. I. x Guat.) A seedling of the
Winslow, a Guatemalan variety. This hybrid, like the Collin-
son, shows evidence of West Indian ancestry. The tree is rapid
growing, but not as vigorous as the Collinson. Like the Trapp,
it is sometimes "set-back" following a heavy set of fruit, and
may drop most or all of its crop.
The fruit is nearly round and weighs 22 ounces or more.
It is dark green and smooth-skinned. The flesh is pale yellow
and has a rich, delicate flavor.
The trees sometimes shed their entire crop in late November
within a period of two or three days. This is especially true
of young trees of this variety. It is possible that this tendency
may be overcome by a different fertilizer treatment for this
variety.
The fruit is rather large for market purposes, but ripening
as it does from November to January 1, it finds a ready sale
at good prices.
LULA.-(Mex. x Guat.) This variety, thought to be a Mex-
ican-Guatemalan hybrid, originated at Buena Vista, Florida.
The tree is a strong grower and free bearer. Both tree and
fruit are subject to scab, which, however, may be controlled
by timely spraying with Bordeaux mixture.
The Lula is hardier than most of the Guatemalan varieties
and is a favorite in the central part of the State. The fruit
is pear-shaped, slightly roughened skin, green, and weighs 16
to 24 ounces. It is usually mature in time to ship during the
Christmas season, but may be carried until March.
FUERTE.-(Mex. x Guat.) This is the leading variety grown
in California, but thus far has proven unsatisfactory in Flor-








AVOCADOS IN FLORIDA


ida. The tree grows well here and is very cold-resistant. The
fruit under Florida conditions is susceptible to anthracnose.
Growers in the central part of the State, as well as on the lower
East Coast, report an uneven ripening of the individual fruits.
The Fuerte is not recommended for commercial planting,
but may be of value for breeding purposes in producing hardy
varieties.
OTHER VARIETIES.-Many other varieties have been planted
in Florida, most of which have been discarded as commercial
possibilities because of one or more undesirable features. Some
have not been thoroughly tested, and several years will be
required to bring out their merits or faults, as the case may
be. A number of seedling varieties of much promise are being
propagated and others will no doubt come to light in the fu-
ture. Budwood of new varieties, originating in California and
the countries of tropical America, is being introduced and
tried out. As in the past, a large percentage of these new
varieties will probably prove valueless for commercial plant-
ing, but out of this number some will be retained and perpet-
uated as desirable varieties.
Small plantings of some of the following are grown, but are
not considered as standard commercial varieties: Schmidt,
Blakeman, Dickenson, Colla, Sharpless, Lamat, Solano, Nabal,
Collins, Winslow, Queen, Knight, Itzamna, and Panchoy.
In Central Florida hardier varieties are desired for plant-
ing. The following hold more promise for this section than the
West Indian varieties: Collinson, Lula, Taylor, Eagle Rock,
and Itzamna. During some winters the temperature drops so
low in this section that fruit of late maturing varieties may be
injured.
SOIL
The avocado will grow and bear fruit on a wide variety of
soils. In Dade County, where most of the avocados in Florida
are grown, the soil is a coralline limestone overlaid in some
places with a light colored sand, but throughout the greater
portion of this section with a scant surface layer of a reddish
and somewhat heavier soil. The limestone is comparatively
soft and when not broken too deeply retains moisture well. The
surface of this land is very uneven. In the depressions pock-
ets of red soil are found which contain a good percentage of
organic matter. The customary practice in this section is to
scarify the land before planting. A special designed scarifier
is used for this purpose.
Sandy soils with a hardpan layer close to the surface have
proven generally unsatisfactory for avocado culture, and coarse,
deep sands dry out too quickly for best growth. Trees planted
in Central Florida on sandy land having a clay subsoil within








DEPARTMENT OF AGRICULTURE


three feet of the surface have made good growth. Better re-
sults were obtained on this type of soil where heavy cover crops
were grown, which increased materially its moisture holding
capacity.
Several plantings of avocados have been made on muck soils.
Some types of muck when well drained have proven suitable
for avocado culture. A rank growth is made on these soils and
a somewhat different fertilizer treatment from the usual
practice is necessary for the production of good crops. Some
objection has been raised as to the shipping and keeping qual-
ity of avocados grown on muck soils.
The avocado tree will not stand "wet feet." In this respect
it is not as adaptable as citrus trees. Groves on low rock land
have been killed or badly injured by overflow even where the
water came scarcely as high as the crown root and remained
only a few days.
The ideal avocado soil is a fairly moist, heavy loam, and best
results will be had when groves are planted on this type.
PROPAGATION
Avocados may be propagated by budding or grafting, or by
seed. Seeds are viable for two or three weeks after being re-
moved from the fruit if kept in a cool dry place. Since they do
not reproduce the variety, the seed method of propagation is
rarely used except to produce new varieties. Cuttings are diffi-
cult to root, although experiments with certain other sub-
tropical plants indicate that bottom heat would greatly facil-
itate rooting.
Shield budding is the method commonly employed in com-
mercial avocado growing, the procedure being essentially the
same as with citrus. When properly done it is reasonably suc-
cessful, although-more care is required in the selection of bud-
wood than with citrus, and the stocks must be small and
vigorous.
The best season for budding the avocado is from the first
of November through February. Buds which have broken into
growth should not be used, nor should those from which the
outer bud scales have dropped. Some nurseries plant the seed
in the open and bud the young seedlings in the nursery row.
The general practice, however, is to plant in boxes 6x6x12
inches in lath houses.
In the process of budding, a T-shaped or inverted T-shaped
incision is made in the stock near the ground. The bud is cut
in the form of a shield from 1 to 11/2 inches long, depending on
the size of the stock. A very sharp, thin-bladed knife should
be used and the cut made with one sliding stroke. Buds which
are gouged out make poor unions with the stock, and are
likely to die. After the bud is inserted it is wrapped with








AVOCADOS IN FLORIDA 21

waxed cloth or raffia, most propagators preferring the former.
If growth is active, the wrapping must be loosened after two
or three weeks to prevent binding. In order to force the bud
into growth the top of the stock should be pinched back at
this time. Other buds along the stock will break into growth
and keep up an active flow of sap. These may be allowed to
develop for three or four weeks.
When the bud has made a growth of three or four inches, it
should be tied back to the stem of the seedling with raffia. Af-
ter the bud has reached a height of about one foot, the seedling
stub should be cut off just above the bud union, and the cut
surface covered with grafting wax.
Whip grafting of terminal buds on very young, tender seed-
ling sprouts has met with some success, as has also a method
of chip or shield budding on similar tender growth.
Sometimes it is desirable to top-work old seedlings or varie-
ties which because of shy bearing or other objectionable qual-
ities are unprofitable. It was formerly considered very diffi-
cult to graft old avocado trees, but a form of cleft graft has
been developed which is very successful, if the work is done
when the tree is not in active growth. Trees to be grafted are
sawed off 1 to 4 feet above the ground, depending on the diam-
eter of the trunk. If possible, several "nurse" limbs should,be
left to take care of the sap flow.
The cleft is made with a saw and should be 3 to 5 inches
deep, according to the length of the cion. A wedge is then
driven into this opening until the lower end of the cleft begins
to split. Cions about one-half inch in diameter and five to
eight inches long, of more mature growth than is used for
budding, are trimmed on two sides along the lower end to a
point at the bottom. A cion is placed in the cleft at each side
and forced downward so that the cambium coincides with
the cambium of the stub. The wedge is then partly withdrawn
and the projecting portion sawed off, so that the cions are held
in place by pressure. The cleft should be filled and all cut sur-
faces covered thoroughly with grafting wax. A strip of heavy
paper is then tied around the stub, projecting above the
top of the cions and partly filled with clean sand. This is
watered regularly to prevent the cions from drying out. The
collar may be removed after the cions have started growth.
Other methods of top-working are employed, the usual one
being shield budding. The trees are cut back in November or
December leaving some of the lower branches to keep the tree
in a growing condition. Within a few weeks sprouts will
grow from the trunk and these may be budded in the same
manner as described for young seedlings.
The cleft grafting method described above is more detailed
in operation than shield budding, but produces a fruiting tree























































Fig. 8. Making the cleft.
Top-working old Trees.


Fig. 9. After eions have been inserted.


















































Fig. 10. Collar partly filled with sand. Fig. 11. Grafted tree, 18 months after top-working.
Top-working old Trees.








DEPARTMENT OF AGRICULTURE


one season earlier. Many varieties when grafted on vigorous
stocks will fruit the second season after being grafted.
Other methods of budding and grafting have been used, but
those described above are most commonly employed.
The question of rootstocks upon which to bud or graft the
avocado is far from settled. In this State it is customary to
use West Indian seedlings as stock. Seeds are readily ob-
tainable from Cuba and from culls in this State. Seedlings of
this race are generally more vigorous than those of the Gua-
temalan or Mexican. The Guatemalan seems to bud as well on
the West Indian as on seedlings of its own race. West Indian
buds on Mexican stock have been less successful, but do well
on Guatemalan. It is probable that the hardiness of the tree
is influenced to a certain degree by the kind of rootstock upon
which it is growing. Further investigation is necessary to
show the extent of this and other effects of stock on the top.
PLANTING AND CARE OF THE GROVE
Planting distances in Florida avocado groves vary with the
variety, type of soil and choice of the grower. Early plantings
were made at 25x25 or 25x30 feet, but the tendency is toward
closer planting, either 18x20 or 20x20 feet. A wider spacing
should be allowed every eighth row to provide for a roadway.
Trees planted closely shade the ground sooner and approach
more nearly the jungle condition of the trees as found in their
native home in the tropics.
Windbreaks are very helpful in the prevention of wind in-
jury to trees and fruit. If the land is available, the windbreak
should consist of two rows of trees planted in staggered for-
mation and extending completely around the grove. This
method of planting encourages low branching which is most
effective in breaking the force of the wind. Even moderate
winds are detrimental to the growth of the avocado, due to
the excessive transpiration which results. This is especially
true during the dry, hot spring period.
The grove should be protected by a firebreak made by clear-
ing a space 20 or 25 feet wide outside the windbreak. An oc-
casional harrowing of this area will be necessary in order to
keep down vegetation.
Avocados may be planted in Florida at any time of the
year. Probably the best time to plant boxed trees is during
the latter part of September, as by this time the hottest
weather of the year is past and there is usually plenty of
rain for several weeks to aid the trees in becoming established.
Trees planted in early spring must be watered regularly and
often, as the months of March, April and May are normally
the driest of the year. Twice a week is not too often for the








AVOCADOS IN FLORIDA 25

trees to be watered during dry periods, until they are well es-
tablished.
The early plantings of avocados on the limestone soils of
Southeastern Florida were made without the use of dynamite.
Shallow holes were dug in the rock, and surface soil contain-
ing considerable amounts of humus was used in filling around
the trees. In some cases stable manure was added, and mixed
with the soil. Trees planted in this manner and given reason-
ably good subsequent care made phenomenal growth and pro-
duced good crops of fruit.
The practice of late years has been to dynamite holes in the
rock to a depth of 11/ or more feet, using surface soil together
with some of the limerock to fill in around the tree. Six to
eight pounds of stable manure are mixed with the soil in each
hole. The trees are planted on a mound so that they are set
at four or five inches higher than the surrounding ground. A
basin should be made about the tree to hold water.
When boxed trees are planted the bottom of the box is re-
moved and the tree set in place. The soil is packed firmly
around it, after which the sides of the box are cut away and
the tree is watered well.
Bare root trees have been planted with success when de-
foliated several days before removing from the nursery row.
The planting should be made in later winter or early spring
to give best results, as the trees are then ready to make good
growths as soon as they have become established.
Sometimes trees planted in holes dynamited in the limerock
have grown off well for a year or two, but during the third or
fourth year a subnormal condition was evident, which has been
variously termed "yellows," marl chlorosis, and "rosetting."
This condition is thought to be induced by an excess of lime.
The subject is taken up more fully under the heading of dis-
eases.
Another objection which has been raised to the practice of
blasting holes for tree planting is that the capillarity of the
rock is broken, thus preventing the free movement of moisture
from the lower levels to the tree roots. Because of these con-
ditions it is believed best to plant in shallow holes, either dug
or blasted lightly.
Shading is necessary to prevent sunburn, especially if the
trees are planted during the spring or summer months. Fer-
tilizer sacks may be used for this purpose. Three stakes should
be driven in the ground so that the sack when stretched over
them will shade the tree from the south and southwest. Some
growers shade with large palmetto leaves which are usually
available at no cost.
The basins around the trees should be filled with a mulch of








DEPARTMENT OF AGRICULTURE


straw, grass, or any coarse material in order to prevent the
soil from drying out and to keep the roots cool.
Young avocado trees are less cold-resistant than when older
and should be given some protection during the months when
frosts occur. A temporary shelter made of burlap or other
available material will often save the trees from severe frost
injury. Large palmetto leaves may be used for this purpose.
Most types of soil upon which avocados are planted in Flor-
ida are deficient in humus, and some practice should be fol-
lowed whereby the humus content will be increased. On sandy
soils clean cultivation during the dry season followed by cover
crops in the summer rainy season has produced good results.
On the rocky soils of southern Dade County the method of cul-
tivation varies with different growers. With some the usual
practice is to allow the native weeds and grasses to grow
throughout the rainy season, keeping them mowed or hoed
closely during the drier winter and spring. In the younger
groves, where the tree roots have not spread in the row mid-
dles, a dragging or harrowing is given in the fall. When the
trees are older, deep cultivation is liable to be very injurious
to the root system.
In other groves a system of permanent mulching is used
with excellent success. The material used is grass or weeds cut
from the row middles or brought in from outside sources.
Where this plan is followed the feeding roots grow into and
just beneath this material. As the mulch decays more must be
added so that the roots will not be injured by exposure to sun
and air.
The growing of leguminous cover crops to add nitrogen and
organic matter to the soil is coming more and more into favor.
Crotalaria, velvet beans, pigeon peas, cowpeas, beggarweed,
Sarawak bean, yam bean, and others are excellent soil builders.
The best time for planting is during the latter part of May
when the summer rainy season begins. In preparing the land
for sowing the seed, several harrowings or dragging are
necessary to kill the weeds so that the cover crop will crowd
out other growth and make a good stand. It is best to sow a
somewhat larger quantity of seed than is usually recommended
because of the persistence and rapid growth of native weeds
at this season. One harrowing is given after the seed have
been sown in order to cover them lightly. Once established
most of the legumes mentioned above will reseed and make
good stands every year.
IRRIGATION
Irrigated avocado groves are rare in Florida. The avocado
requires an abundant supply of water for best growth, and
while the normal amount of rainfall is ample, it is not well


















































Fig. 12. Avocado grove with crotalaria cover crop.








DEPARTMENT OF AGRICULTURE


distributed. Spring droughts are not infrequent in South
Florida and this is the season when the trees should be mak-
ing their best growth following the longest period of dor-
mancy. If the grove is planted on very dry soil, some system
of irrigation should be installed. Even on soils which are
more retentive of moisture, irrigation is good insurance.
INTERPLANTING
All varieties of avocados, as far as is known at present. fall
into two classes as regards flower opening, shedding, and re-
ceiving pollen at different periods during the day. These
periods are so timed that most varieties of one class will shed
pollen when varieties of the other class are ready to receive it.
There is apparently no provision for self or close pollination
since the male or female arts of the same flower or of flowers
on the same tree do not function at the same time. Varieties
selected from these two reciprocating groups and interplanted
should increase greatly the chances of pollination and fruit
setting, provided they bloom at the same season. The avocado
flower is insect pollinated and hives of bees kept in or near the
grove should aid materially in bringing about pollination.
It is not recommended that interplanting be carried to an
extreme. Alternate blocks of three or four rows each of two
reciprocating varieties should afford ample opportunity for
cross-pollination. Varieties which are similar in cultural re-
quirements should be selected for interplanting, as groves thus
planted may be handled more efficiently. Waldin and Trapp
are examples of West Indian varieties which may be inter-
planted to good advantage. Of the Guatemalans, Wagner and
Linda, or Lula (hybrid), and Eagle Rock are suitable.
Much progress has been made in solving the problem of
fruit setting, but more remains to be learned. Instances of
heavy setting of fruit on isolated trees of certain varieties
have been reported, and it is possible that the fruit of the
avocado, or a part of it, may set without pollination. How-
ever, in the light of present knowledge on the subject, the prac-
tice of interplanting as suggested above should be followed.
PRUNING
Little pruning of the avocado is necessary. Dead, broken,
or diseased branches should be removed, preferably during the
winter when the tree is in least active growth. Avocado wood
is very soft and brittle, and when pruned the cut surfaces
should be painted with some protective material, which will
not injure the wood. White or red lead paint is satisfactory if
not made too thin. A large proportion of oil in the mixture
may cause injury to the wood. There are several specially








AVOCADOS IN FLORIDA 29

made tree paints on the market which are very satisfactory.
When cuts are left unpainted, white grubs, or borers, are
sometimes found deep in the pith. These insects work their
way downward and eventually kill the limb.
Small limbs which have borne a very heavy crop of fruit
are often devitalized and should be cut back to strong healthy
wood. This is especially the case with Trapp and Waldin.
Limbs resting on the ground should be removed, as much
of the fruit produced on them is bruised or scarred to such an
extent as to be unsalable. Some of the fruit on such limbs is
made unfit for the market by being nibbled by rats and other
animals which are very fond of the avocado.
Compact, low-headed trees are more easily handled in spray-
ing, pruning, picking, and other grove operations, and are less
liable to wind damage. Some varieties, especially of the Gua-
temalan race, tend to grow very tall and should be kept pinched
back while young to encourage a more spreading growth.

YIELDS
Some varieties, especially of the West Indian race, often
bear a few fruits the year after being planted. It is best to
remove these fruits as soon as they have set, as the carrying
of a crop at this age will check the growth of the tree. Trees
which overbear when young often die back after the fruiting
season.
Seedlings come into bearing later than budded varieties, five
to eight years usually being required.
Trapps, at five years of age, will under good cultural treat-
ment, produce about two crates per tree. Waldins yield some-
what less than Trapps, and Pollocks less than Waldins.
No crop records are available showing the yields of Guate-
malan varieties over a long period of years. In general they
have not borne as heavy crops in this State as the West In-
dians. At present, however, Guatemalan fruit, on account of
its season of ripening, has commanded much higher prices than
fruit of the West Indian varieties. This factor should be
considered in making a choice of varieties for planting.

INSECTS AND OTHER PESTS
Early plantings of avocados in Florida were almost wholly
free of injurious insects. From various sources several pests
have been carried into the groves, and together with native in-
sects which have adapted themselves to the avocado, may cause
considerable damage if not held in check by spraying or other
means.
The avocado tree is more susceptible to injury from certain








DEPARTMENT OF AGRICULTURE


sprays than are citrus trees. Particular care must be taken in
mixing or applying oil emulsion sprays. Several of these are
on the market and are useful in the control of certain insects.
A strength of 1 gallon to 70 gallons of water is used for most
spraying in the avocado grove where oil is required. In very
hot weather spraying with oil emulsions often results in severe
burning and shedding of the leaves. Wherever possible, this
work should be done during the late fall and winter months.

RED SPIDER
This insect is very small, but due to its bright red color can
be seen with the naked eye. It sucks the juices of the more
mature leaves, feeding on the upper surface only. If abundant
they soon cause the foliage to turn reddish brown. This dis-
coloration is first evident along the midrib of the leaf, but
gradually widens as the insects extend their feeding area, until
the entire leaf presents a browned appearance as though
scorched by fire. By this time the leaf has become devitalized
and is soon shed.
CONTROL.-The heavy rains of summer aid in ridding the tree
of red spiders, but cannot be depended upon to completely con-
trol them. In fact, the hot weather of this season seems to
favor their increase, and if the interval between rains is long,
as sometimes happens, the infestation is likely to become more
severe. Thorough spraying with either oil emulsion, lime-
sulphur, or nicotine sulphate, or dusting with sulphur will
usually keep this pest in check. Oil emulsion sprays should not
be applied for at least three weeks after the trees have been
dusted with sulphur, as burning of the foliage may result.
Neither should sulphur follow oil emulsion for the same length
of time.
DICTYOSPERMUM SCALE

This pest is found in the avocado nursery as well as on bear-
ing trees in the grove. Varieties of the West Indian race are
preferred by this insect, although many, if not all, of the Guate-
malans are attacked by it. In the grove it is found on the twigs
and young vigorous limbs, and occasionally on the foliage.
Heavy infestations weaken the smaller branches, causing them
to turn black and die. The first indication of injury is a cracked
and roughened appearance of the branches. When this condi-
tion is noted, control measures must be started immediately if
serious damage to the tree is to be avoided.
The adult insect sucks the juices of the tree. It is brownish
grey in color, small, and circular in outline. The surface of the
scale is nipple-like.








AVOCADOS IN FLORIDA


CONTROL.-Oil emulsions are usually effective in controlling
this scale. Two applications, three or four weeks apart, are re-
quired if the infestation is heavy. The best time to spray is
during the months of December and January, as there is less
chance of burning the foliage at this time. However, if the in-
sect is abundant at other seasons, spraying should not be post-
poned. The twice-stabbed lady-beetle feeds upon the dictyo-
spermum scale and has aided greatly in keeping this pest in
check, but cannot be depended upon for complete control.

PYRIFORM SCALE
This insect is not usually as destructive to the tree as dictyo-
spermum scale, but secretes a honeydew in which the sooty mold
fungus develops, which mars the appearance of the fruit.
The adult scale is reddish brown, pear shaped, and about one-
eighth of an inch long. It is commonly found on the underside
of the foliage, where it sucks the plant juices.
CONTROL.-Spraying as for dictyospermum scale will control
this pest. Thorough coverage of the underside of the foliage is
necessary.
AVOCADO WHITE FLY
This white fly is much smaller than those attacking citrus.
The adult is less than one twenty-fifth of an inch in length. In
the pupa, or resting, stage, the insect may be easily identified
by its circular shape and fringe-like margin. In this stage it
is lemon yellow in color, as is also the body of the adult.
CONTROL.-The usual method of control is by spraying with
oil emulsion. Two sprayings, if thoroughly applied to the
underside of the foliage, will in most cases effect a cleanup.
The first application should be made in November and another
in the spring after the fruit has set.
AVOCADO LACE-BUG
During the dry spring months this insect is sometimes found
heavily infesting the lower surface of the foliage. It seems to
prefer the West Indian race, although it has been found on
Guatemalans. The lace-bug is a sucking insect and wherever
it feeds, causes pale spots to appear due to the extraction of
plant juices. The insect may be easily seen with the naked eye
and can be recognized by the lace-like structure on its wings
and body.
CONTROL.-Spraying with 40 per cent nicotine sulphate at
the rate of one part to 900 parts of water gives good control.
One pound of calcium cassinate added to 100 gallons of spray
causes it to spread more readily over the foliage.








32 DEPARTMENT OF AGRICULTURE

BLOSSOM ANOMALA
Some seasons during the blooming period this beetle causes
serious damage by feeding on the blossoms. They hide in the
soil during the day and large numbers of them may be found
feeding on the blossoms at night. The adult is about one-fourth
inch long, brownish in color, resembling the so-called "June
bug" or May beetle, to which it is closely related.
CONTROL.-Arsenate of lead at the rate of 11/ pounds to 50
gallons of water is the most effective spray to use in controlling
this pest.
AVOCADO LEAF-ROLLER
Frequently in mid-summer the avocado is attacked by larvae
of a small grayish moth. These larvae, called leaf-rollers, fold
the leaves by drawing them inward from the margins. They
are chewing insects and if numerous give the foliage a very
ragged appearance. The injury caused by this insect is usually
.not sufficient to warrant spraying. Arsenate of lead, as recom-
mended for the blossom anomala, gives satisfactory control.
TENTWORM
This insect, like the leaf-roller, feeds on the foliage. During
the winter and early spring months the larvae spin a web about
a cluster of leaves, in which they live, feeding on the foliage
until the pupa, or resting stage is reached. Sometimes small
white grubs are found feeding on the tentworm larvae, and
have in some instances effected almost complete control. If
spraying is necessary, lead arsenate, as recommended above,
may be used.
BORERS
Occasionally, in newly planted groves, white grubs, resem-
bling the larval stage of peach tree borers, may be found deep
in the pith of limbs which have been pruned and left unpainted.
These borers work their way downward toward the trunk, de-
stroying all growth as they go, and may eventually kill the
tree. Large trees are attacked and may be seriously injured
if the insects are not removed in time.
CONTROL.--The only practical control method is by cutting
back to sound wood, making sure the borer is not left in the
limb, and painting the cut surface with some material which
will stick and form a protective covering.

OTHER INSECTS
Among the other insects which feed upon the avocado are the
leaf-thrips, blossom-thrips, mealy bug, and brown aphis, the








AVOCADOS IN FLORIDA 33

last named being found principally in the nursery on young
seedlings. It is seldom that control measures are necessary for
any of this group, as the injury caused by them is slight.
RODENTS
If the cover crop in the grove is dense, it affords a hiding
place for rats and field mice, which are particularly fond of the
avocado. Sometimes much of the fruit on the lower limbs is
nibbled by these pests and rendered unfit for sale. Removal of
limbs within reach of these animals, and disking or dragging
the cover crop will do much toward reducing the loss of fruit
from this source.
DISEASES
The principal diseases which attack the avocado in Florida
are scab and black spot. Diseases of minor importance and
seldom requiring control measures are rusty blight, blotch, and
powdery mildew. Spraying as a preventive of scab and black
spot, when properly done, will hold in check the other fungus
diseases.
AVOCADO SCAB
This disease is caused by a fungus closely related to the
fungus which causes scab of citrus. It is more common on
young plants in the nursery than on bearing trees, although it
causes considerable injury to foliage and fruit of certain vari-
eties unless preventive measures are taken to avoid it. The
disease attacks only young and tender growth. The quality
of mature fruit is not affected, although the outward appear-
ance is marred and severe infections may cause the fruit to
be dwarfed and misshapen. Such fruit must go in the lower
grades with the resulting lower returns to the grower.
CONTROL.-Spraying with 4-4-50 Bordeaux mixture as fol-
lows will, under most conditions, keep the scab under control;
the first application into the bloom, a second application three
weeks later, and a third three weeks after the second.
BLACK SPOT
This fungus disease enters the fruit through a break in the
skin and forms round, dark sunken spots wherever it becomes
established. Unlike scab, this disease may cause decay of the
flesh below the spot, making the fruit valueless for shipping.
Black spot may be controlled by spraying with a 4-4-50 Bor-
deaux mixture as follows: the first application about three
weeks after the fruit has set; the second, three weeks later; and
a third application three weeks after the second. The last
application may be omitted if the disease has not been prevalent








34 DEPARTMENT OF AGRICULTURE

in the grove the previous season. If the sprayings are made as
recommended for the control of scab, black spot will usually be
kept under control also, unless the grove is badly infected.
Blotch, rusty blight, and powdery mildew are fungus diseases
which yield readily to treatment. Bordeaux mixture is an effec-
tive control and should be applied where injury from these dis-
eases is apparent.
PHYSIOLOGICAL DISEASES
Troubles of this nature are brought about, in most cases, by
an unbalanced condition of the soil, whereby the tree is unable
to make use of certain elements necessary for its best growth
and development. The symptoms of such conditions are varied
and not always well-defined. Such terms as "frenching,"
"rosetting," and diebackk" are used to describe trees thus
affected. Definite information as to the cause of these troubles
is lacking. However, in the Miami-Homestead region, where
these conditions are most prevalent, there is reason to believe
that the large amounts of lime made available by dynamiting
holes for planting and otherwise pulverizing the limerock, are
detrimental to the trees. It is only since this practice has been
followed that the troubles mentioned above have become preva-
lent in this section.
To correct the condition of over-alkalinity which has appar-
ently been brought about by an excess of soluble lime in the soil,
a number of methods may be followed, all with the view of add-
ing to the soil acid forming materials which neutralize the lime.
Fertilizers which leave an acid residue in the soil should be used
if practicable. Flowers of sulphur applied to the soil and
worked in should prove beneficial. The growing of leguminous
cover crops and mulching the trees heavily will add organic
matter to the soil, which in the process of decay gives off or-
ganic acids. There is no definite information at hand showing
the preference of the avocado as to soil reaction. Citrus trees
thrive best in a soil which is slightly acid, and the indications
are that this is also true of the avocado.
FERTILIZERS
Most of the early growers of avocados in Florida used the
same fertilizers as were being applied to citrus trees. It be-
came evident, however, that a different scheme of fertilization
would be necessary. Organic sources of ammonia have re-
placed a large part of the nitrate of soda or sulphate of am-
monia formerly used, and the percentage of ammonia has, in
most cases, been increased. The formulae used by different
growers vary considerably, and little systematic attention has
been given to the subject.








AVOCADOS IN FLORIDA 35

One of the fertilizer manufacturers on the lower East Coast,
who supplies a large proportion of the avocado fertilizers, gives
the following formula as being most commonly used: For the
February application, a mixture containing 5 per cent am-
monia, 8 per cent available phosphoric acid, and 2 per cent
potash. All of the ammonia is derived from organic sources.
For the May or June application, a 4-6-8 mixture, all of the am-
monia being from organic sources, and the phosphoric acid
half from acid phosphate and half from steamed bone meal.
For the October application, a 4-6-8 mixture, the ammonia be-
ing derived wholly from organic sources. In addition to the
three regular applications, there has developed a tendency to
make a separate application of sulphate of potash to shy-bear-
ing varieties in October, at the rate of 8 to 10 pounds to the
mature tree.
Young trees should be fertilized with a mixture analyzing
higher in ammonia and lower in potash, and should receive at
least one more application per year than is given bearing trees.
One pound per tree is given at each application the first year.
This amount should be doubled during the second year, and
increased as the trees become older. Five-year-old trees, if
they have made good growth, should receive 8 to 10 pounds
per application, and older trees in proportion to size and age.
Stable and poultry manure are very beneficial to the avocado.
Besides their value as a fertilizer, they add humus and bacteria
to the soil.
The reaction of the soil should govern, to some extent, the
choice of materials which go into the fertilizer mixture. If
the soil in the grove is highly acid, materials such as nitrate of
soda, basic slag meal, etc., which leave an alkaline residue in
the soil, should be used. Where the soil is strongly alkaline,
sulphate of ammonia and organic ammoniates will aid in cor-
recting the condition.
Much is yet to be learned about fertilization of the avocado.
Only through intelligently planned and carefully carried out
tests, extending over a long period of years, can definite in-
formation be gained as to the best practices to follow.

PICKING, PACKING AND MARKETING
Avocados are usually picked with orange clippers. A long
picking pole is used by some growers for reaching fruit in the
top of tall trees. A sharp bladed hook is attached to the end
of the pole, below which is fastened a small bag in which the
fruit drops when cut.
When the fruit is mature the first pickings should be made
from overloaded branches. If left longer on the tree, such fruit








DEPARTMENT OF AGRICULTURE


will increase very little in size and may cause a dying back of
the branches on which they are borne. Fruit of the Trapp and
Waldin clusters heavily at times and particular attention is
necessary with these varieties.
Avocados are never soft enough to be eaten when picked from
the tree. They must be laid aside for one or more days in order
to ripen fully and several fruits should be tested in this manner
before harvesting the crop for shipment.
In southern Florida the standard container for avocados is
the tomato crate, which measures 12x12x24 inches, and holds
approximately forty pounds of fruit. Two types of iced crates
are in use for long distance shipment. In one the ice compart-
ment, which is the center, holds about twelve pounds of ice. In
the other type the ice compartment is above the fruit, extend-
ing over the entire pack. This style crate has an ice capacity
of twenty pounds. The tomato lug, similar to that used by
California tomato shippers, which holds 25 pounds of avocados,
and a flat, holding 10 pounds, are used by the Florida Avocado
Growers' Exchange in addition to those described above.
In packing the fruit, a layer of excelsior, or wood wool, is
placed at the bottom of the crate, and another layer on top of the
pack. Some is also stuffed around the sides to hold the fruit in
place. The bulge pack as is used with citrus fruits is imprac-
ticable with avocados, as they cannot withstand the pressure
without injury. Wrapping the fruit with tissue paper has been
tried, but the practice is no longer followed. Wrapped fruit
heats more quickly and is likely to ripen too soon.
The pack, or number of fruits to a crate, varies with the
variety and type of crate used. The Trapp packs from 28 to 80,
the most common being 36 to 48. Waldins run from 28 to 64;
Pollocks from 18 to 36; Taylors from 36 to 80; Winslowsons
from 18 to 36; Lulas from 32 to 48.
The grading of avocados in Florida for shipment has been
with many growers a matter of simply culling out unsalable
fruit and shipping the remainder without regard to quality or
appearance. Standard grades have been established by a few
growers and shippers, and by adhering closely to the grades,
they have built up a profitable business. The Florida Avocado
Growers' Exchange markets fruit under the trade name of
Flavocado. The grades Fancy, Choice, and Plain, or similar
ratings, are used by individual shippers.
Prices received for Florida avocados depend to some extent
upon the variety, but largely on the season. Quotations f. o. b.
Southern Florida have ranged in some seasons from $2.50 per
40-pound crate in September to as high as $35.00 in January
and February. Expansion of the avocado industry in this State
will depend in a large measure upon the demand for the fruit
































-tejl


Fig. 13. Pollock avocados packed in ventilated crates, ready for shipment.








DEPARTMENT OF AGRICULTURE


as a staple food, and it is around a price of ten to twelve cents
a pound that the industry must be built.
Late summer and fall maturing fruits must meet the com-
petition from Cuba and other tropical countries, whose ship-
ments to this country are increasing ever year. Fruit of the
Guatemalan varieties, which matures in late winter, reaches
the market when shipments from California are heavy. From
a marketing standpoint, the best varieties of avocados for
Florida growers are those which mature in late November and
December. During this period there is a gap in the market,
and it is at this season that the demand for salad fruits is
greatest. No ideally suited variety has as yet been found that
matures its main crop during these months, although several
promising seedlings have fruited and some of these may be
found worth propagating.
The practice of shipping immature Guatemalans to the holi-
day markets cannot be too strongly condemned. The avocado
is a new and totally different fruit to the American public, and
the novice is almost certain to react unfavorably to the first
taste if the fruit is unripe.
Avocados are shipped from Florida to all sections of the
United States. Most of the shipments are made to three or four
of the largest cities, New York taking the largest quantities.

COMPOSITION AND USES OF THE FRUIT
A leading horticulturist, who is an authority on subtropical
fruits, has said that an acre of land will yield a larger amount
of food when planted to avocados than it will in any other tree
crop known at present.
The avocado has been termed the "Salad Fruit from the
Tropics" and the "Aristocrat of Fruits." It has been well said
that it is not a fruit for the pushcart peddler. As a fruit, it has
a most unusual composition and is in a class by itself. In fact,
the avocado must meet the competition of salad vegetables prob-
ably more than that of fruits. It contains a higher percentage
of fat and more protein than any other fresh fruit. The total
dry matter in the edible portion is greater than that of any
other fruit. The digestibility of the fat is equal to that of butter
fat. In sugar content the avocado is low. The caloric, or energy
producing value is over 1000, being more than twice that of
other fresh fruits and far in excess of lean meat.
The dietetic value of any fruit, aside from its nutrient con-
tent, lies in its succulency, minerals, vitamins, and organic
acids. In these respects the avocado stands near the top of the
list of cultivated fruits. The delicate, nutlike flavor of the fruit
is unique, and to most people, decidedly pleasing.








AVOCADOS IN O'3RIDA 39

The fruit is used in many ways, te most popular being "on
the half shell," with the addition of citrus fruit juices or salt.
When sliced or cut into cubes, it makes an ideal component of
salads. In the tropics the fruit is added to soups at the time of
serving. Ice cream made from fully ripe fruit is delicious and
this outlet offers much promise in the utilization of surplus
fruit as production increases.
Experiments in canning have met with but little success. The
flavor, as well as the vitamin content, of the fruit is largely
destroyed by cooking.
Investigation of various by-product possibilities will be nec-
essary as production is increased. At present the demand for
fresh fruit takes care of all production and there is no problem
of oversupply.

PUBLICATIONS OF VALUE TO THE FLORIDA
AVOCADO GROWER
Manual of Tropical and Subtropical Fruits, by Wilson Popenoe.
The Macmillan Company, 1920.
Avocado Culture in Florida, by T. Ralph Robinson, Physiolo-
gist, Bureau of Plant Industry, U. S. D. A.
Cost of Avocado Grove DevekT)pmnnt up to and Including the
Fifth Year-Miami-Homestead District. R. A. Carlton, Ag-
ricultural Agent, West Palhn Beach, Fla.
Check List of Avocado Varictio(, by I. J. Condit.
Avocado Diseases (Bul. 161, Florida Experiment Station).
The Avocado, Its Insect Enemies and How to Combat Them
(Farmers' Bulletin 1261).
Pollination of the Avocado (Circular 387, U. S. Dept. of Ag-
riculture).
Annual Proceedings of the Florida State Horticultural Society.

ACKNOWLEDGMENTS
Grateful acknowledgment is given Mr. W. J. Krome, of
Homestead, Florida, who has criticized the text of this bulletin
and who, through his extensive knowledge of avocado culture,
has made this bulletin possible.
Much of the data on fertilization of the avocado was supplied
by Mr. F. B. Rue.
The publications listed above have been drawn upon freely
for information.
Photographs used herein have been loaned through the
courtesy of Mr. Krome, except as otherwise indicated.




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