FROM THE LIBRARY
AIfllM 4IIi lil
Bulletin No. 24
L. R. TOY
State of Florida
Department of Agriculture
NATHAN MAYO, Commissioner
Prepared and Published in Co-operation with the College of
Agriculture, University of Florida, Gainesville.
T J. APPLEYARD, INC., TALLAHASSEE, FLORIDA
DEPARTMENT OF AGRICULTURE
Nathan Mayo, Commissioner of Agriculture......
T. J. Brooks, Director, Bureau of Immigration
Phil S. Taylor, Supervising Inspector................
John M Scott, Agricultural Editor.....................
No man in Florida knows more about avocado culture than
Mr. W. J. Krome, of Homestead, Fla., who has made this bulle-
tin 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 manscript. 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,
cAvocados in Florida
By L. R. TOY
Prepared and Published in Co-operation with the College Agriculture,
University of Florida, Gainesville.
T HE NAME "avocado" originated from the Aztec word for
this fruit, "ahuacall." It is the name used in publications
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 tropical
America. It has been grown as a dooryard tree for hundreds 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
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
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. In-
terest in avocado culture during this period was at a low ebb. It
was only through the foresight and persistence of a few pioneer
DEPARTMENT OF AGRICULTURE
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
1800 acres of avocados planted in Dade County. Approximately
1200 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 Americana, 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 32F. unless that temperature holds for a longer period than
two or three hours. When four or five years old they will stand
26 or 27F. 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 con-
ditions a few fruits of some varieties will hang on until well
into January. The amount of rainfall influences the season, un-
usually 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 char-
acterizes fruit of this race is from 1 64 to 1/16 of an inch thick.
AVOCADOS IN FLORIDA 7
Fig. 1. Trapp variety, 4 years old (West Indian Race).
8 DEPARTMENT OF AGRICULTURE
TRAPP.-This variety was originated on the place of Mr. C. L.
Trapp of Coconut Grove, Florida, and was first propagated in
1901. It is the most widely planted variety in the State and one
of the most productive. The tree is a comparatively 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 yellowish
green, smooth-skinned, and of medium to large size, weighing
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 Jan-
uary, but the bulk of the crop matures in October and November.
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 envia-
ble 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 propogated in 1916. The
tree is a vigorous grower, productive, and hardier than most
varieties of its race. The fruit is oblong, with a characteristic
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 January
1. The main crop matures, however, in November, following 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-pollination, as they are reciprocat-
ing 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 ma-
turing their fruit, and in spraying requirements, handling costs
POLLOCK.-The Pollock originated at Miami, Florida, about
1896, and was first propagated in 1901. The fruit is oblong to
L~~~a~a~; '~~rar~ cu~ T; r r.
Fig 2 Grveof4 )ea ol tee (Tap vaiey)
Fig. 3. Grove of 12 year old trees (Trapp variety).
AVOCADOS IN FLORIDA 11
*1 *~'* .
Fig. 4. Pollock Avocado (West Indian).
12 DEPARTMENT OF AGRICULTURE
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 is of excel-
lent 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 induced
by a separate application of sulphate of potash in September or
October. More extensive experimentation along this line is to
SIMMONDS.-This is one of several selected seedlings originat-
ing at the United States Plant Introduction Gardens, Miami.
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 coincides with that of the
Pollock. These two varieties are "reciprocating" in their daily
flower opening, thus affording opportunity for cross-pollination.
It is therefore well to interplant the two in alternating blocks
of three or four rows each.
This race is native to the highlands of Guatemala and southern
Mexico. It is more cold-resistent than the West Indian, with-
standing a temperature of 23F. with but slight injury under
Several varieties of this race are grown commercially in Flor-
ida, but on a smaller scale than the West Indian. Guatemalan
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 ex-
cept in a few varieties.
Because of its hardiness, the Guatemalan race promises to be-
come of much commercial value in parts of Florida subject to
temperatures too low for West Indian varieties.
AVOCADOS IN FLORIDA 13
Fig. 5. Taylor Variety, 31/2 years old (Guatemalan Race).
Fig. 6. Taylor Avocado (Guatemalan).
AVOCADOS IN FLORIDA 15
WAGNER.-Originating in California in 1908 as a seedling of
the Royal variety, the Wagner avocado has been tested in Flor-
ida and in 1922 commercial plantings were made. The tree is
fairly vigorous and has proven more prolific than the average
Guatemalen 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 origi-
nating 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 grower, which is an ob-
jectionable 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 charac-
teristic of several varieties 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 some-
what roughened skin. In quality and flavor the Taylor is fair
In Dade County the fruit matures from December 15 to Febru-
ary 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 ma-
turity 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 fertilization
will be worked out which will result in heavier crops of this
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 exception-
ally strong and rapid grower and fruits well, commencing to bear
16 DEPARTMENT OF AGRICULTURE
at an early age. The new growth is a rich wine color and when
the tree is in "flush" it is strikingly ornamental.
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 favor is
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 toward black
in color, with a thick, roughened rind. The average 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 elliptical.
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.
This is the hardiest of the three races of avocados. Many Mex-
ican varieties withstand fully as much frost as the orange. The
foliage is characterized by an anise-like odor. Fruits of the dif-
ferent 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 is better
adapted and since the period of ripening is the same as that of
the Mexican race, there has been no incentive to plant varieties
of the latter. Some varieties of this race may, however, prove of
value to colder section 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 Florida.
Several varieties have been fruited, the most desirable being
Puebla and Gottfried.
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 evi-
dence of such mixed parentage.
Fig. 7. Northrop Avocado (Mexican).
DEPARTMENT OF AGRICULTURE
GUATEMALAN-WEST INDIAN hybrids originating in Florida ap-
pear 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 (luatemalans. It
is because of this fact that hybrid varieties are receiving consid-
erable attention in Florida.
COLLISON.-(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 Collison is one of the most rapid growing and vigorous
varieties grown in the state. Both the tree and fruit are resistant
to scab. The fruit is dark, glossy green, smooth-skinned and pear-
shaped. The average fruit weighs about 20 ounces. It is of excel-
lent 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 districts
it has suffered as little injury from low temperatures as many of
the Guatemalan varieties.
WINSLOWSON, OR RoilFS.-(W. I. x Guat.) A seedling of the
Winslow, a Guatemalan variety. This hybrid, like the Collinson,
shows evidence of West Indian ancestry. The tree is rapid grow-
ing, 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
LULA.-(Mex. x Guat.) This variety, thought to be a Mexican-
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 Florida.
The tree grows well here and is very cold-resistant. The fruit
AVOCADOS IN FLORIDA
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
OTHER VARIETIES.-M1any other varieties have been planted in
Florida, most of which have been discarded as commercial pos-
sibilities because of one or more undesirable features. Some
have not been thoroughly tested and several years will be re-
quired to bring out their merits or faults, as the case may be.
A number of seedling varieties of much promise are being propa-
gated and others will no doubt come to light in the future. Bud-
wood 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 planting, but out of this number
some will be retained and perpetuated as desirable varieties.
Small plantings of some of the following are grown, but are
not considered as standard commercial varieties: Schmidt, Blake-
man, Dickenson, Colla, Sharpless, Lamat, Solano, Nabal, Collins,
Winslow, Queen, Knight, Itzamna, and Panchoy.
In Central Florida hardier varieties are desired for planting.
The following hold more promise for this section than the West
Indian varieties: Collinson, Lula, Taylor, Eagle Rock, and Itza-
mna. During some winters the temperature drops so low in this
section that fruit of late maturing varieties may be injured.
The avocado will grow and bear fruit on a wide variety of
soils. In Iade 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 pockets
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
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
three feet of the surface have made good growth. Better results
were obtained on this type of soil where heavy cover crops were
20 DEPARTMENT OF AGRICULTURE
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 quality of avo-
cados 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 overflows even where the
water came scarcely as high as the crown roots and remained
there 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.
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 subtropical
plants indicate that bottom heat would greatly facilitate 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 6 x 6 x 12 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/ 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 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
AVOCADOS IN FLORIDA
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
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. After
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 varieties
which because of shy bearing or other objectionable qualities are
unprofitable. It was formerly considered very difficult 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 diameter of the trunk. If
possible, several 'nurse" limbs should be left to take care of the
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 project-
ing portion sawed off, so that the cions are held in place by
pressure. The cleft should be filled and all cut surfaces 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 pre-
vent 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 one
Fig. 8. Making the cleft.
Top-working old Trees.
Fig. 9. After cions 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
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 obtainable
from Cuba and from culls in this State. Seedlings of this race
are generally more vigorous than those of the Guatemalan or
Mexican. The Guatemalan seems to bud as well on the West In-
dian as on seedlings of its own race. West Indian buds on
Mexican stock have been less successful, but do well on Guate-
malan. 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 25 x 25 or 25 x 30 feet, but the tendency is toward
closer planting, either 18 x 20 or 20 x 20 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 injury
to trees and fruit. If the land is available, the windbreak should
consist of two rows of trees planted in staggered formation and
extending completely around the grove. This method of plant-
ing 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
The grove should be protected by a firebreak made by clearing
a space 20 or 25 feet wide outside the windbreak. An occasional
harrowing of this area will be necessary in order to keep down
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.
AVOCADOS IN FLORIDA
Twice a week is not too often for the trees to be watered during
dry periods, until they are well established.
The early plantings of avocados on the limestone soils of south-
eastern Florida were made without the use of dynamite. Shallow
holes were dug in the rock, and surface soil containing consider-
able 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 reasonably good subse-
quent care made phenomenal growth and produced good crops of
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 removed
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
Bare root trees have been planted with success when defoliated
several days before removing from the nursery row. The plant-
ings should be made in late winter or early spring to give best
results, as the trees are then ready to make good growth 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 diseases.
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 conditions it
is believed best to plant in shallow holes, either dug or blasted
Shading is necessary to prevent sunburn, especially if the trees
are planted during the spring or summer months. Fertilizer
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
The basins around the trees should be filled with a mulch of
26 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 avail-
able 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 Florida
are deficient in humus, and some practice should be followed
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 cultivation
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 middles, a 1, i._-.._1-' or harrow-
ing is given in the fall. When the trees are older, deep cultiva-
tion is liable to be very injurious to the root system.
In other groves a system of permanent mulching is used w-ith
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 sow-
ing the seed, several harrowing 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.
Irrigated avocado groves are rare in Florida. The avocado
requires an abundant supply of water for best growth, and while
the narmol amount of rainfall is ample, it is not well distributed.
Spring droughts are not infrequent in South Florida and this is
the season when the trees should be making their best growth.
SO-,--AL t -~-.
Fig. 12. Avocado grove with crotalaria cover crop.
28 DEPARTMENT OF AGRICULTURE
following the longest period of dormancy. If the grove is
planted on very dry soil, some system of irrigation should be in-
stalled. Even on soils which are more retentive of moisture.
irrigation is good insurance.
All varieties of avocados, as far as is known at present, fall
into two classes as regards flower opening, shedding, and receiv-
ing 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 and female parts of the same flower or of flowers on the
same tree do not function at the same time. Variaties 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 require-
ments should be selected for interplanting, as groves thus planted
may be handled more efficiently. Waldin and Trapp are ex-
amples of West Indian varieties which may be interplanted 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 set-
ting of fruit on isolated trees of certain varieties have been re-
ported and it is possible that the fruit of the avocado, or a part
of it, may set without pollination. However, in the light of
present knowledge on the subject, the practice of interplanting
as suggested above should be followed.
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 sur-
faces should be painted with some protective material, which
will not injure the wood. White or red lead paint is satisfac-
tory if not made too thin. A large proportion of oil in the
mixture may cause injury to the wood. There are several
AVOCADOS IN FLORIDA 29
specially made tree paints on the market which are very sat-
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
Guatemalan race, tend to grow very tall "and should be kept
pinched back while young to encourage a more spreading
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
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 West Indian varieties. This factor should be consid-
ered 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
DEPARTMENT OF AGRICULTURE
The avocado tree is more susceptible to injury from certain
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 burn-
ing and shedding of the leaves. Wherever possible, this work
should be done during the late fall and winter months.
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 ma-
ture 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 some-
times 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.
This pest is found in the avocado nursery as well as on bearing
trees in the grove. Varieties of the West Indian race are pre-
ferred 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
gray 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.
This insect is not usually as destructive to the tree as dictyo-
spermum scale, but secrets 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
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 under-
side 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.
During the dry spring months this insect is sometimes found
heavily infesting the lower surface of the foilage. 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 sulfate at the
rate of one part to 900 parts of water gives good control. One
pound of calcium cassinate added to 100 gallons of the spray
causes it to spread more readily over the foilage.
32 DEPARTMENT OF AGRICULTURE
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
Frequently in mid-summer the avocado it 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 foilage a very
ragged appearance. The injury caused by this insect is
usually not sufficient to warrant spraying. Arsenate of lead,
as recommended for the blossom anomala, gives satisfactory
This insect, like the leaf-roller, feeds on the foilage. During
the winter and early spring months the larvae spin a web about
a cluster of leaves, in which they live, feeding on the foilage
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.
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 un-
painted. These borers work their way downward toward the
trunk, destroying 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.
Among the other insects which feed upon the avocado are the
leaf-thrips, blossom-thrips, mealy bug, and brown aphis, the last
AVOCADOS IN FLORIDA 33
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.
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 avo-
cado. 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
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.
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 consider-
able injury to foliage and fruit of certain varieties unless pre-
ventive 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 appearance 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 follows
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.
This fungus disease enters the fruit through a break in the skin
and forms round, dark sunken spots wherever it becomes estab-
lished 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 in the grove
34 DEPARTMENT OF AGRICULTURE
the previous season. If the spraying are made as recommended
for the control of scab, black spot will usually be kept under con-
trol 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.
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," "roset-
ting," 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 prevalent 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 adding
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 organic 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.
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 precentage of ammonia has. in
most cases, been increased. The formula a used by different
growers vary considerably, and little systematic attention has
been given to the subject.
AVOCADOS IN FLORIDA
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
bearing 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 pick-
ing 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 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 40 pounds of fruit. Two types of iced crates are
in use for long distance shipment. In one the ice compartment.
which is in the center, holds about twelve pounds of ice. In the
other type the ice compartment is above the fruit, extending 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 impractic-
able with avocados, as they cannot withstand the pressure with-
out 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 Grow-
ers 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
Fig. 13. Pollock avocados packed in ventilated crates, ready for shipment.
C~ . ~
DEPARTMENT OF AGRICULTURE
February. Expansion of the avocado industry in this State will
depend in a large measure upon the demand for the fruit 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 competi-
tion from Cuba and other tropical countries, whose shipments to
this country are increasing every year. Fruit of the Guatemalan
varieties, which matures in late winter, reaches the market when
shipments from California are heavy. From a marketing stand-
point, 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 pro-
ducing 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 content,
lies in its succulency, minerals, vitamins, and organic acids. In
these respects the avocado stands near the top of the list of
AVOCADOS IN FLORIDA
cultivated fruits. The delicate, nutlike flavor of the fruit is
unique, and to most people, decidedly pleasing.
The fruit is used in many ways, the 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 neces-
sary as production is increased. At present the demand for fresh
fruit takes care of all production and there is no problem of
PUBLICATIONS OF VALUE TO THE FLORIDA
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 Development up to and Including the
Fifth Year-Miami-Homestead District. R. A. Carlton, Ag-
ricultural Agent, West Palm Beach, Fla.
Check List of Avocado Varieties, 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-
Annual Proceedings of the Florida State Horticultural Society.
Grateful acknowledgement is given Mr. W. J. Krome, of
Homestead, Florida, who has criticized the text of this bulle-
tin and who, through his extensive knowledge of avocado cul-
ture, 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
Photographs used herein have been loaned through the
courtesy of Mr. Krome, except as otherwise indicated.