AGRIC. DEFT

THE

CULTIVATION

OF

CITRUS
FRUITS

A Short Treatise

with Special Reference to

Fertilization.

HILLMAN

Second Edition, Revised and Extended

PUBLISHED BY

WILLIAM S. MYERS, F.C.S., Director,

Nitrate of Soda Propaganda.
Late of New Jersey State Agricultural College.

John Street and 71 Nassau, New York, U. S. A,

THE Nitrate Propaganda is not engaged in the
Sale of Nitrate of Soda but will furnish a list of
dealers to all who apply for it*

It should be remembered that the original package of
Nitrate of Soda contains approximately 200 Ibs* of normally
dry Nitrate of Soda*

Nitrate of Soda is generally sold in the original pack-
ages and should be stored or kept in a dry place* Glass
Works and Manufacturers of Dynamite and Gunpowder
usually have Nitrate on hand*

If you have any difficulty in obtaining Nitrate, either
by reason of prohibitive prices or undue delays or on
account of inability of dealers to supply you promptly, let
me know at once, and the difficulty will be investigated
immediately*

Correspondence concerning excessive freight charges
is invited* Nitrate is sometimes discriminated against by
the Transportation Companies by charging a chemical rate
instead of a fertilizer rate; please secure and forward all the
facts, including Freight Receipts*

When ordering Nitrate, please be sure to request your
Dealer, Manufacturer or Importer to have your invoice
clearly and distinctly marked as "Fertilizer*" This is
necessary that this valuable Farm Chemical may be
properly classified in order to avoid the discrimination
practised by the Railroads against Nitrate*

WILLIAM S. MYERS, Director

NITRATE PROPAGANDA
John Street and 7* Nassau, New York

The Cultivation

of

CITRUS FRUITS

A Short Treatise

with Special Reference to

Fertilization.

HILLMAN

Second Edition, Revised and Extended

PUBLISHED BY

WILLIAM S. MYERS, F.C.S., Director,

Nitrate of Soda Propaganda.
Late of New Jersey State Agricultural College.

John Street and 71 Nassau, New York, U. S. A,

:^>

LtnfetiHHK*/

r*f
^.^

Published February, 1907.

Preface.

The following leading authorities, among others, have been consulted
in the preparation of this work :

1 . California Fruits and How to Grow Them ,• by Edward J. Wickson,

A.M., San Francisco, 1900.

2. Citrus Fruit Growing in the Gulf States ; by P. H. Rolfs ; Farmers'

Bulletin No. 238, U. S. Department of Agriculture.

3. Citrus Fruit Culture / by J. W. Mills ; Bulletin No. 138, University

of California, Agricultural Experiment Station, Sacramento, 1902.

4. Twenty-second Report of the Agricultural Experiment Station of the

University of California, Sacramento, 1904.

5. Annual Report of the Porto Rico Agricultural Experiment Station,

1904; by D. W. May; U. S. Department of Agriculture, Office
of Experiment Stations.

6. Propagation and Marketing of Oranges in Porto Rico; by

H. C. Henricksen ; Bulletin No. 4, Porto Rico Agricultural
Experiment Station ; Washington, 1904.

7. Citrus Fruits in Hawaii ; by J. E. Higgins ; Bulletin No. 9,

Hawaii Agricultural Experiment Station ; Washington, 1905.

8. Pomelos; by H. Harold Hume; Bulletin No. 58, Florida Agricul-

tural Experiment Station ; Jacksonville, Fla., 1901,

9. El Naranjo ; por el Dr. B. Alino ; Valencia, 1900.

10. Tratado complete del Naranjo; por Prof. B. Giner Alino; Valencia,
1901.

JOSEPH HILLMAN.

London, January, 1907.

274395

The Cultivation of CitFus

A Short Treatise with Special Reference
to Fertilization.

The cultivation of citrus fruits forms an important
Industry as well in extensive districts of California as in
Florida and sections of Louisiana and Mississippi; it has
established itself in Hawaii and it has passed the experi-
mental stage in Porto Rico and elsewhere in the West Indies.

Although successful fruit-growing is a highly remuner-
ative pursuit, much is required to insure success. Good judg-
ment, with expert knowledge, needs to be exercised in the
selection of soil and location, in the choice of stock and bud,
in the cultivation and fertilization of the grove, in the treat-
ment of diseases and in the picking, packing and marketing
of the crop.

The variety of conditions prevailing in the wide regions
over which citrus fruits may be cultivated with profit, extend-
ing, as these do, from about 35° North Latitude on the
Pacific Coast of the United States to about 18° North Lati-
tude, or well within the Tropics, renders it impracticable
to lay down rules of unvarying application for their culture
in all districts. All that can be undertaken within the limits
of this brief treatise is to indicate certain principles applicable
to the rational practice of horticulture, wherever exercised,
and to make suggestions regarding soils, climatic conditions,
selection of varieties, suitable fertilization, methods of cul-
tivation, and the rest, that may afford general guidance.

Again, although the orange may be taken as a type
representative of the other members of the group of citrus
fruits in many respects, and notably in regard to their re-
quirements in the matter of soils and cultural methods,
special treatment in certain particulars is required for the
profitable cultivation of lemons, limes and pomelos, and these
will, accordingly, be separately touched upon.

Climatic Conditions.

Climatic conditions must be a primary consideration
in the selection of a locality for fruit-growing on a commer-
cial scale.

It may be stated generally that the winter temperature

Cultivation of should not fjjj be,QW ^ tQ . R Q£ continued cold

Citrus Fruits 1^1 i /- i n -•->•/-

although a temperature of as low as 24 F., if not continued

6 for more than a few hours at a time, will be withstood by

orange trees when in a dormant condition.

In Florida, the danger point of cold is regarded as
being 28° F. for fruit and 24° F. for foliage.

The mean temperature of seasons is of more importance
than the mean temperature of the year. In other words*
the relative distribution of heat over the seasons, rather
than the absolute amount received during the year, is that
which determines the fitness or unfitness of the climate of
a district for the growing of citrus fruits.

The rainfall should not be excessive ; certainly not more
than 50 to 70 inches annually. Heavy rainfall is especially
a disadvantage if it occurs at the time when the trees should
be dormant preparatively to blooming, or at the season when
the fruit has to be marketed. Thus, citrus fruit orchards
should never be planted where autumn and winter rains are
the rule, as on the rainy side of islands in the West Indies.
The orange tree is exacting of a regulated water supply ; with-
out this it will yield poor fruit.

The site should be sufficiently elevated above the low
ground of the region to secure free drainage and immunity
from frosts; whilst, where irrigation must be practised, the
plantation should be so located that water is easy of access
and distribution.

Soils.

Although citrus trees will adapt themselves to almost
any kind of soil, the orange tree in particular thrives best
in a deep, moderately rich and permeable soil; one fairly
retentive of moisture and yet not heavy enough to prevent
escape of excessive rainfall. It should be light enough to
work, readily and yet not so loose as to dry out rapidly.

Sub-strata of hard-pan or of sand and gravel must be
carefully avoided, and examination for such defects should
be made before laying out a plantation.

A siliceous loam with some lime and clay, deep and
with capacity for necessary irrigation, is that which the
orange tree prefers. Its lightness and depth allow the root
system of the tree to extend and develop easily, thus inducing

rapid growth; the cultivation of such soil requires but little The
labour and can be carried to a sufficient depth, so that deep Cultivation of
rooting is promoted; whilst the injurious extremes of drought ltrus
and water-logging are avoided.

At the same time, it is undoubtedly true that whilst
rich alluvial soils produce citrus trees of luxuriant growth,
which often bear enormous crops, the finest and choicest
fruits are largely produced upon soils of a much lower grade
of fertility. As Rolfs has remarked:

* { In fertile soils the plant food is seldom properly balanced and
present in the condition best suited for producing the finest fruits, nor is it
possible to influence the contents or quality of the fruit by applying different
forms of chemical fertilizers. If, therefore, a field is normally sufficiently
fertile to produce a citrus crop for an indefinite number of years, it is
usually impossible to influence the quality of fruit markedly by means of
fertilizers. Upon soils which are nearly sterile, however, trees may be
started and fed with just such chemicals as will produce the finest quality of
fruit. It therefore happens that soils which formerly were considered
absolutely worthless for agricultural purposes are now made to produce large
crops of most excellent fruit."*

We are not prepared to endorse to their full logical
sequence the views thus expressed; but, with certain limita-
tions, they serve to inculcate forcibly the value attaching to
the skilled employment of chemical fertilizers in the pro-
duction of high-class fruits.

Selection of Varieties.

No variety of citrus is suitable for cultivation in all re-
gions of what may be termed the citrus belt. Thus, the navel
orange, which is pre-eminently adapted for California, is
of but little value in Florida. On the other hand, certain
varieties of pomelo are of exquisite flavour when fruited in
Florida, but are not of the same excellence when grown in
California. It is essential, therefore, to test in the district
in which it is to be grown the particular variety which it is
desired to introduce.

Indeed, so much will depend upon local conditions and
market requirements, that we consider it to be inadvisable
to make specific recommendations under this head. Suffice
it to say that the choicest varieties, capable at the same time
of heavy yields, and those taking a permanently prominent

* Farmers' Bulletin No. 238, U. S. Department of Agriculture.

The place in the market are, prima facie, those which should
Cultivation of be selected.
Citrus Fruits

Preparation of the Land.

o

Clearing should be thorough; everything that would
interfere with good cultivation should be removed; roots
should be grubbed; the ground should be levelled, and, where
needed, provision should be made for drainage and irriga-
tion.

The soil should be broken up and reduced to a fine tilth,
which will permit of careful planting and staking.

In most cases it is advisable to grow a field crop the
first year; better cultivation and aeration of the soil is thereby
secured and any sprouting from old roots is killed out.

The orange in particular should have full possession of
the soil immediately surrounding it, undisputed by grass,
weeds or other trees. Its success will be indifferent under the
uhole-in-the-grass" method of cultivation.

Propagation and Choice of Stocks for Budding.

The orange cannot be trusted to come true from seed,
and for fruiting purposes seedlings may be regarded as
unprofitable to plant. Growth from the seed is now, how-
ever, the method almost exclusively followed for the pro-
duction of stocks for budding, to the exclusion of growth
from cuttings or from layers, and it is by far the best.

In growing orange seedlings, good plump seed should
be selected and it should never be allowed to dry. Unless
it is to be sown at once, it should be mixed with moist sand
for storing.

The best time for sowing is after the soil has become
warmed in the spring.

The choice of seedling stocks for budding is a matter
of primary importance. A deep root system and broadly
extending laterals, not too near the surface, are essentials
to the ideal stock.

It has been said by so eminent an authority as Wickson
(California Fruits, Chapter XXX, p-356) that "the orange
root is the best foundation for an orange tree, and the seed
of the seedling sweet orange is the main reliance''. The
sweet-orange, however, would appear to be a surface-growing
stock which has few deeply penetrating roots. In the Uni-

ycrsity of California Experiment Station trials, the sour- The

orange stock has been found to be decidedly hardier, and Cultivation of

, , i A Citrus Fruits

in every way better than the sweet-orange stock. Among

its other good qualities, it is resistant to alkali. 9

But the pomelo is deservedly becoming the favourite
stock in southern California. Its laterals are found at a
greater depth than the laterals of the sweet orange; it pro-
duces more fibrous roots than does either of the other stocks,
and the tree is consequently a ravenous feeder. It has suc-
ceeded better at the Experiment Station of the University
of California than has the sour stock, which seems to lack
uniformity of root growth, sometimes having but few lat-
erals, in which case the crops are small.

Pomelo seedlings are said also to have made the best
growth in the nursery.

Seedlings are grown either in boxes or in the open
ground; in either case a rich sandy loam, which will not
bake, should be secured.

The seedlings appear in about six weeks, and with good
care in weeding and in keeping sufficiently— but not ex-
cessively— moist, they will make a growth of about a foot
in the first season.

Planting out in the nursery should be done so soon as
the ground is thoroughly warmed in the spring, when the
seedlings will be about a year old.

The distance between the rows in the nursery should
be at least four feet, to allow of horse cultivation. A dis-
tance of 1 8 inches between the plants in the rows will per-
mit of the roots being sacked, or otherwise protected, when
the plants are to be removed to the plantation.

In taking the seedlings from the seed bed, a few should
be lifted at a time, and it is essential that their roots be kept
shaded and moist until the ground closes on them in the
nursery row.

It is important to have an even stand in the nursery,
and weak plants should be rejected. The seedling trees
are very susceptible of injury by frost, and it is wise to give
them some sort of protection during the winter.

The young plants are usually budded after being one
or two years in the nursery, or at two to three years from the
sowing of the seed. At a convenient time in the winter,
the lower shoots and thorns are removed, so as to leave a

The clear stem of about six inches for the convenience of the
Cultivation of fa^fa^

The best season at which to bud is about the time when
10 the seedling is starting into vigorous growth in the spring.

In general it may be said, however, that budding on good
citrus stock may be done at any time of the year when the
bark of the stock separates easily from the wood. This
always indicates a strong flow of sap. The buds must be
taken from a vigorous, healthy tree of the variety desired.
Good well-matured buds only should be used; those from
both the base and the tip of shoots are frequently defective.

Spring buds start into growth almost immediately, and
have the benefit of the whole summer season for developing
and maturing wood.

After the bud has made a good start, the top of the
stock should be removed at a short distance above it, and
suckers on the old stock should be continually looked for and
removed. The tender shoot of the bud is protected by
tying to the stub, and when the growth of the bud has be-
come sufficiently strong to allow of its supporting itself,
the old stock is smoothly sawn away and the wound covered
with grafting wax, or paint.

Probably, however, a better practice is to supply sup-
porting stakes at once, and to cut the stocks close in lopping,
as, when this is done, the buds are said to make more rapid
growth.

Budded trees are given one or two years' growth in the
nursery and one or two years' growth on the bud, which,
added to the year in the seed bed, makes them three to four
years of age from the sowing of the seed before they are
ready for planting out in the orchard.

To cut a bud properly is not altogether a simple opera-
tion; indeed the whole process of budding is one which re-
quires skill and practical experience, .and it would be scarcely
possible to give here intelligible and adequate directions for
performing it with assurance of success.

Setting Out.

The number of trees to be set out to the acre will de-
pend on the variety selected and the character of the land.
Large-growing citrus trees such as pomelos and the Bahia
and Tardiff sweet oranges, should not be set closer than 100

to the acre, and on soils of a high grade of fertility 75 are The

enough. Smaller growing varieties, such as the mandarin ^ultivatlon °*
6 r ill- i u i Citrus Fruits

group of oranges and the limes, should not be set closer

than 200 trees to the acre. "

In a sandy loam, rich in organic matter, the trees
grow much more vigorously, and should be set farther
apart. In heavy clay soils, their growth is less luxuriant,
and they may be set nearer together.

On the whole, the best arrangement of the trees is that
of planting in hexagons, as shown in the adjoining figure.

This method allows of fifteen
per cent, more trees than setting in
squares, and the ground can be
worked in three different directions,
It also gives better facilities for irri-
gation.

The orange, in common with
other evergreen trees, is extremely
sensitive to exposure of its roots,
and for this reason special precau-
tions have to be taken in handling
the young trees in the process of
Trees planted in Hexagons. transplantation. The manner of
handling will depend in a great measure upon the character
of the nursery soil. Sacking and balling is, no doubt, the
method to be preferred, but it requires a certain degree of
adhesiveness in the soil. Lifting from the nursery when the
soil is too dry, exposure of roots, or careless planting, will
condemn the tree to a slow and sickly growth, and often
kill it outright.

The practice of reducing the top to compensate for the
loss of roots in removal, is essential, but care must be taken
not to carry it too far, lest subsequent growth be thereby
checked.

Fertilization.

Judicious and liberal fertilization is essential to the
intensive culture of citrus fruits. Cultivation, pruning and
irrigation, necessary as they are to the success of the planta-
tion, fail in their object — once the natural fertility of the
land is exhausted or sensibly reduced — if the plant food
absorbed from the soil be not replaced.

The The removal from the soil of the constituents of a

Cultivation of succession of crops brings about sooner or later, sterility or
- exhaustion of the soil from default of nitrogen, phosphoric
IZ acid and potash; and this sterility or exhaustion cannot be

prevented or remedied by any system of cultivation. Field
operations carried out with thoroughness do, indeed, re-
store to the surface soil the elements of fertility which
the rains wash down into the sub-soil, they hasten their solu-
bility and prepare them for assimilation by the plant, but
they replace nothing. It is indispensible therefore to make
good the deficit, and, by means other than cultivation, to
restore to the soil what the crops have removed from it. On
this fact is based the use of manures, and in manuring skil-
fully and adequately lies the secret of successful fruit grow-
ing.

Barn-yard manure used in moderate quantities will re-
store to the soil, to some extent, the elements removed from
it by continuous cropping, but in the case of citrus fruits it
will be inadequate to increase production; employed in
greater quantity and to an excessive extent, its effects are
rather injurious than favourable, since it gives rise to all
the evils attendant upon the application of organic nitrogen
in too large proportion.

Moreover, although barn-yard manure is, in a general
sense, termed a complete manure, it does not, when em-
ployed alone, satisfy the requirements of citrus trees, inas-
much as the quantity of some of its constituents needs to be
supplemented if heavy yields and healthy vegetation are to
be maintained.

Fortunately, the rational application of manures is daily
becoming better understood, and the grower is now in a
position, by the aid of chemical fertilizers, to raise the yield
of his plantation to a maximum^and, at the same time, to
secure for his trees that vigour of growth which enables
them to resist unfavourable climatic conditions and parasi-
tic attacks.

Liberal and judicious fertilization is essential to profit-
able results in the culture of citrus fruits; and the grower
should be the less inclined to stint outlay in the purchase
of fertilizers, because he may be certain of obtaining highly
remunerative returns in the yield and quality of the crop.
The orange tree, in particular, is one that responds gener-

ously to generous treatment by producing fruit of the highest The

quality and in enormous quantity. Cultivation o

4, „ . . . i • . Citrus Fruits

I o manure rationally, it is necessary to take into ac- -

count the nature of the soil, the composition of the plant^ Z3
its food requirements, the quantity and constituents of the
crop and the conditions of vegetation. Acquainted with
these, we are able to determine, with an approximation to
scientific accuracy, what are the elements that have to be
supplied and in what proportion.

The chemical composition of the orange tree — as well
as that of citrus fruits generally — is complex, and varies
somewhat widely, but the following, which represents the
mean of a large number of analyses, will serve as a guide
in the employment of manures :

Analysis of Orange Trees.

In 100 parts.

Nitrogen. Potash. Lime.

Fruit .......... 0.32 °-38 0-32 0.43

Leaves ......... . 0.70 o.io 0.32 0.71

Trunk and branches 0.70 °«43 0.58 0.80

These data clearly indicate that no one element dis-
tinctly dominates the others; for although lime is present
in quantity, that base exists in abundance in most soils and
may be disregarded in the preparation of formulae of ma-
nures, sufficient of it being applied in combination with
phosphoric and sulphuric acids.

In the case of trees, like those of the citrus group,
whose foliage is perennial, and which are of comparatively
slow growth and subjected to only limited pruning, the
elements of fertility consumed in the formation of leaf and
wood are relatively small in quantity, and the greater part
of the plant-food assimilated is expended upon the fruit.
Thus, in determining the nature and quantity of the manures
to be applied, the production of fruit is the principal factor
to be taken into account m arriving at the volume of plant-
foods abstracted from the soil and consequently having to
be replaced.

Let us suppose that an acre of orange plantation (about
100 trees) produces twelve tons of fruit. According to the
analysis given above, this crop will contain:

The Nitrogen 85 pounds

Cultivation of Phosphoric acid 102 "

Citrus Fruits Potash 85 "

14 It will be necessary, then, to restore these elements to

the soil, in one form or another, if the trees are not to suffer
from want of nourishment and to cease to produce maximum
crops of good quality.

On the basis of the foregoing figures, the typical for-
mula of chemical manures, per acre of orange trees, will be :

Nitrate of Soda 560 pounds

Superphosphate of lime (i 6% soluble phosphoric acid) 6l2 "
Sulphate of potash I 70 "

Obviously, however, this general formula must not be
adopted without reference to specific conditions; it must be
modified to meet the requirements of each particular case,
according to the nature of the soil and the state of vegetation
in the plantation.

It may be well to mention here that in the opinion of
some of the most experienced and successful growers of
oranges in Spain, all formulae of manures for the orange
tree should contain sulphate of lime and sulphate of iron,
the quantity varying according to the composition of the soil.
If the land is poor in lime, only gypsum (sulphate of lime)
is employed; if lime is moderately abundant, both sulphates
are used, and if the soil is distinctly calcareous, only the
sulphate of iron.

The formulae which are indicated later on are based
upon that given above, modified in accordance with the par-
ticular requirements of the plantation.

In the first place, the composition of the soil has to be
taken into account. To ascertain this requires a delicate
analysis, which only a chemist can make; but the certainty
which such an analysis affords in the application of manures
renders it of the first importance to the horticulturist. The
cost of it will be repaid in a single season by economies
following upon a close determination of the nature and quan-
tities of the fertilizers to be employed.

In default of an analysis, however, a knowledge of the
physical qualities of soils is of much utility. A clay soil
may be assumed to be rich in potash and poor in phosphoric
acid; a calcareous or limey soil is, on the other hand, gener-

ally rich in phosphoric acid and poor in potash; sandy soils The

are almost always poor in plant-foods, and soils laden with Cultlvatlon of

• u • u «. • u A '4. Citrus Fruits

organic matter — rich in humus — contain abundant nitrogen, .

although it is not always in a form in which it is assimilable is

by plants.

The typical formula will have, therefore, to be modified,
more or less, according to the nature of the soil; the elements
which are deficient or abound in the latter being increased
or diminished correspondingly. As a general rule, all soils
are deficient in phosphates, and therefore it will almost al-
ways be safe, if not necessary, to increase the quantity of the
phosphatic fertilizer indicated in the general formula.

In the case of trees of the citrus family, an excess of
nitrogen induces an exuberant production of wood and leaf,
at the same time that the fruit is rendered thick in rind and
puffy, deficient in sweetness, wanting in aroma and with a
marked tendency to rot. Moreover, a superabundance of
nitrogen in the food of the plant delays maturity; and this
circumstance has to be taken into account according as early
or late maturity of the crop is desired.

Organic nitrogen, as found in cotton-seed meal, dried
blood, guano, barn-yard manure, etc., is especially apt to
bring about a soft, rapid growth, and in certain regions,
especially in Florida, its continued use is found almost cer-
tainly to give rise to "die-back."

If phosphoric acid is largely in excess in the fertilizer,
the fruit will generally be abundant but small, of fine flavour,
and having the seeds numerous, large and of great germin-
ating power.

When potash is superabundant relatively to the other
available constituents of plant food, the tree acquires but
little development; the fruit, however, is juicy, very sweet,
of rich flavour and delicate aroma; the rind is fine and the
seeds small and few in number.

From what has been said it will be sufficiently obvious
by itself alone the part of a complete fertilizer; each is the
complement of the others, each supplements the action of the
others, and conjointly and supplied in suitable proportions,
they bring about the desired results.

The general formula which has been indicated pre-
supposes that the trees to which the fertilizer is to be applied
are large, in full bearing, and yielding a crop of about

The twelve tons of oranges per acre. If the plantation be capable

Cultivation of o£ a neavier yield, on account of its maturity or from the

3 variety being a prolific one, or owing to the nature of the

16 soil, the advantages of the site, facilities for irrigation, the

climate, etc., the quantities of the several fertilizers may

be judiciously increased until the limit of production is found

to have been reached.

On the other hand, if the plantation is naturally one
capable of producing only moderate yields, the trees of me-
dium size and facilities for irrigation absent, the same com-
bination of fertilizers must be employed, but the applica-
tions must be less in quantity; and in determining that
quantity the skill and judgment of the grower will come in.

Superphosphate of lime, containing not less than 14 to
1 6 per cent, of phosphoric acid, is to be preferred as the
phosphatic element in the fertilizer on account of its ready
solubility and relative cheapness. In soils distinctly deficient
in lime Thomas Phosphate (basic slag) may in many cases
be substituted with advantage. If basic slag be used, a
somewhat larger quantity of it should be applied than is
prescribed in the case of the employment of superphosphate
of lime.

Of potash salts, it is advisable to use only the sulphate;
it being the opinion of many experienced growers that the
sulphate communicates to the fruit the greater delicacy and
aroma.

Exact experiments carried out during the past few years
have shown that Nitrate of Soda is the best source of nitrog-
enous food for the orange tree. And here it must be borne
in mind that Nitrogen, from whatever source derived, must
be in the form of a nitrate to be assimilable by the vegetable
organism. Thus, if manures containing organic nitrogen, or
sulphate of ammonia — which yields ammoniacal nitrogen-
be employed, the nitrogen which they contain has to undergo
in the soil a natural process known as Nitrification, in con-
nection with the action of minute organisms which convert
the ammoniacal or organic nitrogen of the manures into
nitric acid and nitrates. For this conversion more or less
time is required, and, whilst the processes last, losses occur
by the giving off of free nitrogen, which the plants are unable
to utilize and which is lost in the atmosphere.

To illustrate these facts, it may be mentioned that horn
shavings and Nitrate of Soda contain, in equal weights, about c^ltivation o
the same quantity of nitrogen, and nevertheless their value ltrus
as fertilizers is very different. The nitrogen of the nitrate li

of soda is in a form in which it is immediately assimilable
by plants, whilst that contained, in organic form, in the horn
shavings nitrifies slowly, three or four years being required
for the completion of the process. The like is the case with
barn-yard manure and all other animal or vegetable manures,
although the nitrification of the organic nitrogen of some
of them is completed in the course of two years or less.

When we remember that 15 to 16 per cent, of the
weight of nitrate of soda of ordinary commercial purity
(95%) is represented by Nitrogen, and that i cwt. of it
therefore contains as much nitrogen as ultimately becomes
available from the decomposition of a ton and a half of rich
barn-yard manure, the activity and rapidity of action of this
fertilizer, and at the same time the control which the culti-
vator is able to exercise over its effects, are readily to be
understood.

Another important characteristic of Nitrate of Soda
is the freedom with which it permeates the soil. The roots
have not to wait for nitrogenous food until they can grow
down to it, neither have they to seek it immediately beneath
the surface, to the encouragement of shallow rooting; and, as
a consequence, plantations dressed with nitrate of soda suffer
less from drought than those deriving their nitrogen from
other sources.

Although the intensive cultivation of citrus fruits can
only be carried on with the aid of chemical fertilizers, the
application of organic manures to the plantation should not
be omitted, if only as a means of maintaining the mechanical
condition of the soil. Where barn-yard manure is at dis-
posal, it should be spread over the grove lightly, so that
each tree receives only a small amount. Good results are also
to be obtained by ploughing under, every second or third
year, a leguminous crop. Among the plants suitable for
green-manuring tested at the Experiment Station of the Uni-
versity of California, a variety of Horse Bean, Ficia faba,
has been found to be one of the most suitable for use in citrus
orchards. All the horse beans make rapid winter growth,
and growth ceases with the coming of hot weather. Thus,

The the crop can be ploughed under early in the spring, and the
Cultivation of ground be subsequently thoroughly pulverized for the reten-
Citrus Fruits f. • ,. j • u. u^ -T-U - i.
tion or moisture during the summer drought. I heir abun-

18 dant root growth is an advantage in favour of these beans

for green manuring. Not only do the roots assist in opening
the soil, but by their decay they add materially to the humus
contents of the land.

Apart from the benefit of its mechanical action on the
soil, organic manure thus applied yields up the products of
its decomposition little by little, thereby steadily maintaining
the food supply of the tree; and when the energies of the
latter have to be brought to a maximum for the production
of a heavy crop, the application of the readily assimilable
chemical fertilizers produces its effect with certainty and at
the required vegetative period.

Young Orange Trees.

The first necessity for these is rapid development of
the trunk and foliage; the following is a suitable dressing,
per acre of the plantation :

Nitrate of Soda 35° pounds

Superphosphate of lime 350 "

Sulphate of potash 100 "

The addition of the following will in many cases prove
advantageous :

Sulphate of lime 150 pounds

Sulphate of iron i oo "

The application should be increased to the full dressing
as the yield of fruit becomes more abundant.

Old Orange^Trees.

Old orange trees contain much fixed lime in the trunk
and branches, and they need to have activity imparted to the
sap, foliation and florescence. The following application,
per acre, will be a suitable one :

Nitrate of Soda 600 pounds

Superphosphate of lime 700 *'

Sulphate of potash 150 "

Sulphate of iron 200 "

Adult Orange Trees of Sickly Vegetation. The

Cultivation of

Orange trees the produce of which is scanty and the Citrus Fruits
vegetation sickly and affected by chlorosis are distinctly bene- " ~
fited by the application of a full dressing of nitrate of soda.
The following are the constituents of a suitable fertilizer
per acre of the grove:

Nitrate of Soda 700 pounds

Superphosphate of lime, or Basic slag 350 "

Sulphate of potash 200 "

Sulphate of lime 300 «'

Sulphate of iron I 50 "

Both with this class and with old trees, once they have
recovered themselves and regained normal development, the
total quantity of the fertilizers should be diminished by 15
or 20 per cent.

Trees Producing Much Wood, Foliage and
Flower, but^Little Fruit.

Until of late years it has been the practice to dress such
trees exclusively with phosphates and potash salts, it being
generally believed that nitrogenous manures increased the
tendency to defective fructification.

Careful observation has led to this view being discarded.

It is rare to find an orange plantation that does not con-
tain trees of this character, which, whatever dressing and
cultivation they may receive, continue to bear scantily.
Recourse is now usually had to re-grafting, or "working-
over", and the abundant yields frequently obtained by this
means afford proof that some other cause than food defi-
ciency had induced the partial barrenness.

Mandarin Oranges.

This variety is a greedy feeder and requires an ample
supply of manures ; but, as it is of less size and yields smaller
crops than the ordinary species, it requires proportionately
reduced quantities of the several fertilizers. When in full
bearing, mandarins should receive, per acre, fertilizers in
accordance with the following formula:

Nitrate of Soda 450 pounds

Superphosphate of lime 500 '«

Sulphate of potash 100 "

The Nurseries of Orange Trees.

Cultivation of

Citrus Fruits Previous to planting, there should be thoroughly incor-

~ " porated with the soil, for every 100 square yards: .

Well-rotted barn-yard manure .... 1000 pounds

Superphosphate of lime 50 "

Sulphate of potash 20 "

In spring, 50 pounds of nitrate of soda should be broad-
casted over the same area.

In the second year, the same application may be re-
peated with the exception of the barn-yard manure.

For the seed plot, a heavy dressing of barn-yard manure,
with the addition of a moderate application of superphos-
phate of lime, will suffice.

In spring, the plot should be watered frequently with
a solution of one-half ounce of nitrate of soda in the gallon
of water.

It should be borne in mind that increased applications
of fertilizers will not necessarily produce increased yields,
and that, once the limits are reached of what the plant can
assimilate — and those limits are approximately represented
by the quantities indicated in the formulae given above —
any surplus that may be employed will be unproductive of
good and economical results.

Time and Manner of Application
of Fertilizers.

If any barn-yard manure is to be applied, it should be
turned under at the time of the ploughing which is usually
given shortly after the crop is gathered.

The superphosphate and potash salts should be culti-
vated in during the dormant season of the trees, or, at latest,
sometime before active vegetation commences in the spring,

The nitrate of soda should be broad-casted in three
successive dressings, as follows: A third-part at the outset
of vegetation in the spring; another third-part at least a
fortnight before flowering commences, and the remaining
third-part sometime after the fruit is well set. After each
dressing, shallow cultivation and irrigation may follow with
advantage.

If sulphate of lime is to be employed, it may be mixed The

Cultr

Citrus Fruits

with the last dressing of nitrate of soda ; and the sulphate Cultivation of

of iron, finely pulverized, may be put on a few days later.

If the foregoing directions are acted on, the plantation
will have been adequately manured before the trees come into
flower, the food materials will be fully utilized, and flores-
cence will develop uniformly and be apt for fertilization.

Manures should not be applied during the flowering
period, lest an uneven flow of sap be induced and fructifica-
tion be interefered with.

Earlier or later maturity of the crop depends upon the
period at which the fertilizers are applied, since the earlier
the nutritive principles are taken up and assimilated, the more
quickly they are accumulated in the fruit, and the earlier
will its development be completed.

Accordingly, if early ripening is desired, the applica-
tion of the last dressing of nitrate of soda and of the sulphate
of lime and sulphate of iron should be advanced; if, on the
other hand, it is wished to retard the maturity of the fruit,
the application of this dressing must be correspondingly
delayed.

The fertilizers should be evenly distributed over the
entire area beneath the branches of the trees, with the ex-
ception of a circle of about two feet from the trunk, which
should be protected by a ridge of earth from contact with
the manures and water. This manner of application is essen-
tial, as the fertilizers act almost exclusively through the fine
absorbent rootlets.

Irrigation.

Citrus trees require liberal supplies of moisture. The
exact quantity of water necessary cannot be stated, since it
will vary with the character of the soil, the distribution of the
rainfall, and the care taken in its conservation in the soil.

In California irrigation is general, the number of ap-
plications varying from three to eight yearly. The best
practice can be determined only by the grower himself after
a study of local conditions.

Irrigation by furrows as deep and narrow as practic-
able has been strongly recommended by Professor Hilgard.

The This method consists of running a plough to a depth of a
Cultivation of £OQt or eyen more jn faj.^ furrows, between the rows.
Citrus Fruits XTT, , . i- j • i r
When the water is applied in such furrows, a team can be

driven along the dry strips of land between them, and with a
harrow or other appliances the dry soil can be dragged into
the wet furrows immediately after the irrigation water is
turned off, and evaporation be thus lessened. The surface
soil is kept comparatively dry by this method and there is
nothing to attract root-growth to the surface.

Cultivation.

The main objects of cultivation, using the term in its
widest sense, are two: Winter cultivation for moisture re-
ception, and summer cultivation for moisture retention. The
securing of these objects underlies the use whether of the
plough or of the various kinds of harrows and cultivators.

The orange requires good, clean tillage. If weeds and
grass are allowed to occupy the ground the grove will suffer.
The plantation should be ploughed at least once a year,
immediately after the crop is gathered.

Distinct advantage will be found in varying the depth
of tillage from year to year — say eight inches, twelve inches,
ten inches, fourteen inches, and then eight inches again — ; by
this method what is known as "plow sole", or "hard pan", a
hard and impervious layer of soil which forms when the land
is continuously cultivated to the same depth, will be avoided.

Tillage should follow irrigation as soon as the land is
dry enough to admit of it.

Pruning.

Orange and other citrus trees, except the lemon, re-
quire little pruning after the head has been properly formed.
It is of great importance that the tree be given a proper shape
by judicious pruning and pinching during the first years of
its orchard life. The aim should be to secure a low-headed,
symmetrical tree, of upright growth, covered with a compact,
but not crowded, wall of foliage. Dead twigs in the fruit-
bearing area should be removed and all dead branches in the
interior of the tree be cut out.

Diseases of the Orange.

Cultivation of

The most serious diseases of the orange tree are those citrus Fruits
known as "gum disease" and "die-back". ~^

The treatment for the former is by the use of a wash of
lime, crude carbolic acid and salt. The sour orange stock
is said to be practically proof against gum disease. The
pomelo stock is also resistant to it.

The application of organic manures, and in particular
of barn-yard manure, should be altogether avoided in the
case of trees suffering from gum sickness.

With regard to "die-back" Dr. E. W. Hilgard writes:
"In almost all cases of "die-back," examination has shown some
fault in the sub-soil, which puts the roots under stress. Such fault may be
an underlying hardpan or impervious clay, pure and simple ; or it may be
excessive wetness or dryness of the sub-strata surrounding the deeper roots ;
or the rise of bottom water from below, as in cases of over-irrigation. The
true "die-back" is not properly a disease, but simply the manifestation of
the distress felt by the root-system underground. The first thing needful
is to dig down and examine the roots, and then to relieve whatever fault
may be found, if possible ; which may not always be the case. Sometimes
an appearance similar to the "die-back" is caused by the roots encountering
a marly stratum, which is apt to stunt the growth of the tree, causing it to
put out a multitude of small, thin branches, and sometimes causing the tips
to die off. For this form of the trouble there is no permanent remedy ; the
trees should never have been planted in such ground, any more than in such
as has shallow-lying hardpan or clay."

Pomelos.

As a tree, the pomelo most nearly resembles the orange,
and its culture is virtually the same. It is a rapid grower
and precocious in fruit-bearing. Like all citrus fruits, the
weight and quality of its yields are to a very great extent
a reflection of the care and food given to the tree. It may
be stated as an indisputable fact that the grower who fertil-
izes heavily has the largest crop, the best fruit, and the
largest profit from his plantation.

To attain the standard of excellence the fruit must have
the characteristic pomelo flavour — a pleasant commingling
of bitterness, sweetness and acidity. Among the large
varieties, Duncan, Hall, McKinley, Pernambuco, Standard
and Walters are prominent. Triumph is a good variety,
as well as the Marsh, the latter being notable for the small
number of its seeds. Of the smaller varieties Josselyn is
probably the most characteristic.

It may be calculated that each tree in full bearing will
Citrus1 Fr" °f ^e^ ten boxes of fruit, of the average weight of eighty

pounds per box.

2* Each tree bearing ten boxes or 800 pounds of fruit

will require to be supplied, to make fruit alone, with :

Superphosphate of lime (14% soluble phosphoric acid) 2.86 pounds
Sulphate of potash (50% available potash) ... 5.86 "
Nitrate of Soda (15% nitrogen) 5.86 "

This is on the assumption that the constituents required
for wood growth, etc., will be gathered from the soil, and
no allowance is made for losses by leaching, etc. In practice,
therefore, the quantity of each fertilizer will require to be
amplified.

According to Bulletin No. 58 of the Florida Agricul-
tural Experiment Station, the experience of most growers
points to the use of chemical fertilizers alone for all citrus
trees. The grove fruits more heavily, a better quality of
fruit is obtained and the trees are maintained in a healthier
condition.

Where large amounts of organic fertilizers are used,
die-back will almost surely affect the trees, and fruit contain-
ing a large amount of rag and of poor shipping and keeping
quality is the result.

The Lemon.

The lemon requires a practically frostless situation.
Under favourable conditions the tree blooms and fruits con-
tinuously through the year. It delights in a sandy loam,
but it will thrive on other soils. In southern California the
lemon is profitably grown upon deep clay loams, and even
upon strong red clay soils.

The prevailing stock is the orange seedling. If lemon
seedlings are desired they may be grown in the same way,
but the lemon on its own root will sometimes fail where,
grown on the orange stock, it will thrive. The budding
and planting of the lemon is carried out in the same way as
in the case of the orange. The distance apart of the trees
in the grove varies from twenty to twenty five feet. Greater
care and attention are required to bring the lemon into good
bearing form and to retain it in satisfactory shape than is
the case with the orange.

The lemon responds very freely to the application of The

fertilizers, and the quantity of nitrogen applied may with Cultivation of

advantage be ten or twelve per cent, greater than has been _
prescribed for the orange. 25

The Lime, the Citron, and Minor Citrus Species.

The lime is much less hardy than the lemon. It has
been killed in situations where the orange and lemon have
not been injured.

Limes are grown from seed, the variety usually coming
true from seed. The trees are small and are frequently
grown in hedge form.

The Citron, on the other hand, is quite hardy. As yet
there is no considerable production in California, although
experimental planting is continued with some activity.

Various minor citrus species, including the Bergamot,
are grown to some extent in southern California, but chiefly
for curiosity or ornament.

What has been indicated above in the case of the lemon
will apply generally to the fertilization of these species.

In conclusion we would say that we do not pretend to
have done more in this little work than briefly touch upon
salient points in connection with specified divisions of the
subject. Our object has been to aid the grower of citrus
fruits by pointing to methods of culture which have been
ascertained — chiefly by the labours of the Experiment Sta-
tions— to be the best, and the most likely to be pursued with
advantage and prospective profit.

We expressly disclaim any attempt to lay down hard-
and-fast rules or to give directions which should supersede
the exercise of the planter's own judgment, or replace the
indications afforded by his knowledge of the particular con-
ditions, as respects soil and climate, in which he is working.

General Directions for
the Use of Nitrate of Soda on Staple Crops.

The use of Nitrate of Soda alone is never recommended,
except at the rate of not more than one hundred pounds to
the acre. // may be thus safely and profitably used without
other fertilizers. It may be applied at this rate as a Top-

The Dressing in the Spring of the year, as soon as vegetation be-

Cultivation of gms to turn green; or) 'm other words, as soon as the crops

_ begin new growth. At this rate very satisfactory results are

26 usually obtained without the use of any other fertilizer, and

the Soda residual, after the Nitrogenous Ammoniate Food

of this chemical is used up by the plant, has a perceptible

effect in sweetening sour land.

In most of our Grass experiments where Nitrate was
used alone at the rate of but One Hundred Pounds per acre,
not only was the Aftermath, or Rowen, much improved, but
in the subsequent seasons, with nothing applied to the plots,
a decidedly marked effect was noticed, even on old meadows.
This speaks very well indeed for Nitrate of Soda not leaching
out of the soil. The readily soluble elements are the readily
available elements. The natural capillarity of soils doubtless
is, in most instances, a powerful factor in retaining all readily
soluble elements of fertility.

If this were not so, all the fertility of the world in our
humid regions would, in a season or two, run into the ocean,
and be permanently lost.

This is mentioned on account of certain critics having
taken the trouble to object to the use of Nitrate on the
grounds that it would leach away. A case is yet to be seen
where the after-effect of Nitrate is not distinguishable, and,
in certain cases, such effects have been most marked.

When it is desired to use a larger amount than one
hundred pounds per acre of Nitrate of Soda as a Top-
Dressing, or in any other way, there should be present some
form of Phosphatic and Potassic Plant Food, and we recom-
mend not less than two hundred and fifty pounds of either
Acid Phosphate or fine ground Raw Rock, and two hundred
and fifty pounds of some high-grade Potash Salt, preferably
the Sulphate, or wood ashes in twice this quantity. A much
larger amount than one hundred pounds of Nitrate per acre,
when used alone on staple crops, is generally sure to give an
unprofitable and unbalanced food ration to the plant. For
Market Gardening Crops, Hops or Sugar-Beets, however,
somewhat more may be used alone.

When the above amounts of Phosphatic and Potassic
Fertilizers are used, as much as three hundred pounds of
Nitrate of Soda may be applied with profit. In applying

Nitrate in any ration it is desirable to mix it with an equal The
quantity of land plaster or fine, dry loam or sand.

If you have any reason to suspect adulteration of the
Nitrate you may buy, send several pounds of it to your
Experiment Station for analysis, giving date of purchase, full
name and address of agent, and of the Company which the
seller represents.

Generally on the Pacific Coast Nitrate may be applied
as a Top-Dressing after the heavy Spring rains are over, but
before crops attain much of a start.

Table Showing Prices of Nitrate of Soda
on the Ammoniate Basis.

Figured on Basis of 380 Pounds Ammonia in One
Ton of Nitrate of Soda.

Equivalent Cost Equivalent

Cost per Cost Cost per Ammonia Cost of

Cwt. of Ammonia ton of per Ib. as Nitrogen

Nitrate. per Ton unit. Nitrate. Nitrate. per Ib.

$2.00 $2.10 $40.00 $0.105 $0.128
2.05 2.16 41.00 0.108 0.131
2.10 2.21 42.00 0.111 0.134
2.15 2.26 43.00 0.113 0.137
2.20 2.31 44.00 0.116 0.140
2.25 2.37 45.00 0.118 0.144
2.30 2.42 46.00 0.121 0.147
235 2.47 47,00 0.124 0.150
2.40 2.53 48.00 0.126 0.153
2.45 2.58 49.00 0.129 0.156
2.50 2.63 50.00 0.132 0.159
2.55 2.68 51.00 0.134 0.162
2.60 2.73 52.00 0.137 0.165
2.65 2.78 53.00 0.140 0.168
2.70 2.83 54.00 0.143 0.171
2.75 2.88 55.00 0.146 0.174
2.80 2.93 56.00 0.149 0.177
2.85 2.98 57.00 0.152 0.180
2.90 3.03 58.00 0.155 0.183
2.95 3.08 59.00 0.158 0.186
3.00 3.13 60.00 ™ 0.160 0.189
This table enables one to compare commercial quota-
tions on ammoniates with accuracy. The figures themselves

The are not quotations in any sense of the word, and all the
Cultivation of figures of the table refer only to one grade of Nitrate of

Soda, namely: that containing 15.65 per cent, of Nitrogen,

28 equivalent to 19.00 per cent, of ammonia. It is prepared

merely in order that purchasers may compare the price of
Nitrate of Soda, which is always quoted by the hundred
pounds, with other ammoniates, which are quoted by
the ton unit. In the first column, therefore, are given the
prices per hundred weight of Nitrate of Soda ; in the second
column, the equivalent price of the ammonia per ton unit;
in the third column, the corresponding prices per ton; in the
fourth column, the cost of the contained ammonia per
pound, a figure which is always discussed, but almost never
explained in Station Bulletins, and in the fifth column
are given the corresponding prices of the cost of the Nitro-
gen per pound, a figure also much discussed, but not always
explained in Bulletins. The important figures to remember
are the price per hundred weight, the price per ton and the
equivalent price of the ammonia in the Nitrate per ton unit.
The table is prepared to cover fluctuations in price running
from two dollars per hundred, to three dollars per hundred;
or from forty dollars to sixty dollars per ton.

Increased Yield per Acre of Crops receiving Nitrate at the
rate of 100 pounds to the Acre over those receiving none.

Barley ...... 400 pounds of grain.

Corn . . . . . . 280 pounds of grain.

Oats ...... 400 pounds of grain.

Rye ....... 300 pounds of grain.

Wheat ...... 300 pounds of grain.

Potatoes ...... 3,600 pounds of tubers.

Hay ...... 1 ,000 pounds, barn-cured.

Cotton ...... 500 pounds seed-cotton.

Sugar-Beets ..... 4,000 pounds of tubers.

Beets ...... 4,000 pounds of tubers.

Sweet Potatoes ..... 3,900 pounds of tubers.

Cabbages ....... 6,100 pounds.

Carrots ....... 7,800 pounds.

Onions ....... 1,800 pounds.

Turnips . . . . . . -37 Per cent.

Strawberries ....... 200 quarts.

Asparagus . . . . . • . 100 bunches.

Tomatoes . . . . . . . .100 baskets.

Celery ........ 30 per cent.

Index.

PAGE

Analysis of Orange Trees 13

Analysis of the Soil, Value of 14

Authorities Consulted Preface

Barn-yard Manure 12

Barn-yard Manure does not Satisfy the Food Requirements of Citrus Trees i 2

Barn-yard Manure, How to Apply 20

Basic Slag 16

Bergamot, The 25

Budding 9

Budding, Best Season for , i o

Buds, Spring i o

Buds, Treatment of the i o

Chemical Manures, Typical Formula of 15

Citron, The 25

Citrus Fruits, The Cultivation of, an Important Industry 5

Citrus Fruits, The Cultivation of, Remunerative 5

Citrus Fruits, The Cultivation of, Requires Expert Knowledge 5

Citrus Species, Minor. ... . 25

Clearing the Land . 8

Climatic Conditions Governing Selection of Site for Plantation. ....... 5, 6

Cold, The Danger Point of 6

Cultivation 22

Cultivation, Objects of 22

"Die-back" 15, 23

Drainage 6, 8

Fertilization 1 1 , 23, 24

Fertilization, Limits of .... 20

Fertilizers, How to be Distributed 21,22

Fertilizers, Time and Manner of Application of 20, 2 i

Field Crop, Advisability of Growing a Preliminary 8

Florida Agricultural Experiment Station ; Bulletin No. 58 24

Flowering Period, Manures Not to be Applied During the 21

General Directions for Staple Crops 26

General Formula of Chemical Manures, How to be Modified 16

Green Manuring 17

Gum Disease 23

Hexagons, Planting in 1 1

Horn Shavings 1 7

Horse Beans 1 8

Increased Yield per Acre of Crops Receiving Nitrate 28

Intensive Cultivation, Fertilization Essential to 1 1 , 17

Irrigation 21

Land, Preparation of the 6, 8

Lemon, The 5» 25

Lemon, The, Stock for 24

Lime, The 5, 25

Limits of This Treatise 5

Mandarin Oranges 19

Manures, Organic 17, 18, 23

PAGE

Manures, The Rational Application of 12

Maturity of Crop, Earlier or Later, How to be Regulated 21

Nitrate of Soda 14, 15, 1 6, 17

Nitrate of Soda, Characteristic Effects of 17

Nitrate of Soda, Nitrogen-Contents of 17

Nitrate of Soda, the Best Source of Nitrogen for Citrus Fruits 14

Nitrate of Soda, The Nitrogen of 17

Nitrate of Soda, Time and Manner of Application of. 20

Nitrification 1 6

Nitrogen, Ammoniacal 1 6

Nitrogen, An Excess of, to be Avoided 15

Nitrogen, Nitrate 14, 1 8

Nitrogen, Organic 15, 1 8

Nitrogen, Organic, 111 Effects of its Injudicious Application 15

Number of Trees per Acre of Plantation I o, 1 1

Nursery, Distance Between the Plants in the 9, 10

Nursery, Distance Between the Rows in the 9, 10

Nursery, Lifting From the 1 1

Nursery, Planting Out in the I I

Orange, Diseases of the 23

Orange Plantations, The Produce of 14

Orange Seedlings, Unprofitable to Plant 8

Orange, The, Does Not Come True from Seed 8

Orange, The, Requires Good, Clean Tillage 8

Orange, The, Should Have Undisputed Possession of the Soil of the

Plantation 8

Orange Trees Fruiting Scantily, Treatment of 19

Orange Trees, Nurseries of , 20

Orange Trees, Old, Fertilizers for 1 8

Orange Trees, Sickly, Fertilizers for 19

Orange Trees, Young, Fertilizers for i 8

Orange Tree, The Chemical Composition of the 13

Phosphoric Acid 14, 15

Plantation, Selection of Site for 6

Plantation, The Soil of the, Preparation of 6, 8

Plant Food, Constituents of, Removed from the Soil by Orange Crop . . 12

Planting, Arrangement of Trees in 1 1

Planting Out in the Nursery 9

Pomelos 5 , 9, 23

Pomelos, Fertilizers for 23

Pomelo Seedlings 9

Pomelo Stock, The 9

Potash 14, 15

Potash Salts 1 6

Potash, Sulphate of 1 6, 20

Preparation of the Land 8

Propagation 8

Pruning 22

Rainfall. 6

Re-grafting 19, 22

Seedlings, How Grown ..... 9

Seedlings, How to be Lifted 9

Seedling Stock, Choice of 8, 9

Seed Plot, The 20

Seed, Selection of 7

Setting Out I o

Soil, Exhaustion of the 12

Soils, Physical Qualities of 14.

Soils Suitable for Plantations of Citrus Fruits 6,7

Sour-Orange Stock, The 9

Sowing, Best Time for 8

Staking i o

Stocks for Budding, Choice of 8

Stocks for Budding, Grown from Seed 8

Sulphate of Ammonia 1 6

Sulphate of Iron 19

Sulphate of Lime 19

Sulphate of Potash 14

Superphosphate of Lime 1 6

Sweet-Orange, The, a Surf ace- Rooting Stock 9

Table Showing Prices of Nitrate of Soda on the Ammoniate Basis. ... 27

Thomas Phosphate 1 6

Tillage , 22

Tillage, Depth of 22, 23

Top, Reducing the, at Transplantation 1 1

Transplanting I o, I I

Trees, Number of, to the Acre i o

Varieties, Selection of 7, 8

Vicia Faba , 1 8

"Working-Over" ... 19

received from farmers and
prospective consumers interested in the use of
^^-^ Nitrate of Soda, who are unable to secure it in
their immediate vicinity, will be referred to reliable dealers
who will furnish them with this special fertilizer. Formulas
and valuable information sent free*

Below will be found a list of pamphlets relating to
the use of Nitrate of Soda as a fertilizer, which will be
furnished gratis to persons desiring information upon any
of the subjects named*

Cultivation of Citrus Fruits.

* Field Experiments on Market Garden Crops.
Food for Plants.

* Notes on Four Years' Experiments.
Sugar-Beets for Profit.

Olive Culture.

* Market Gardening with Nitrate.
The Cultivation of the Sugar Cane.
The Cultivation of Tobacco.

The Cultivation of Cotton.

Coffee Planting.

Grass Growing for Profit.

* Included in " Food for Plants."

WILLIAM S* MYERS, F. C S., Director

Nitrate Propaganda

John Street and 71 Nassau, New York

THIS BOOK IS DUE ON THE LAST DATE
STAMPED BELOW

AN INITIAL FINE OF 25 CENTS

WILL BE ASSESSED FOR FAILURE TO RETURN
THIS BOOK ON THE DATE DUE. THE PENALTY
WILL INCREASE TO SO CENTS ON THE FOURTH
DAY AND TO $1.OO ON THE SEVENTH DAY
OVERDUE.

CtC 4 1935

2005

LD 21-100m-7,'33

YC 62118

UNIVERSITY OF CALIFORNIA LIBRARY