ORANGE BITTERS
Family: Rutaceae
Genus: Citrus
Species: aurantium
Common Name: Bitter Orange
Ethnic Names: Ch'Eng, Chin Ch'Iu, Hua Chu Hung, Kuang Chu, Orange Bitters,
Naranja Agria, Neroli, Petitgrain
Properties/Actions: Expectorant, Laxative, Carminative, Stomachic, Hypertensive,
Nervine
Orange, Sweet
Botanical: Citrus aurantium (LINN.), var. dulcis
Family: N.O. Rutaceae
Description
Constituents
Medicinal Action and Uses
Preparations of Bitter Orange
Preparations of Sweet Orange
---Synonyms---Citrus vulgaris. Citrus Bigaradia. Citrus aurantium amara.
Bigaradier. Bigarade Orange. Bitter Orange. Seville Orange. (Sweet) Portugal
Orange. China Orange. Citrus dulcis.
---Parts Used---Fruit, flowers, peel.
---Habitat---India, China. Cultivated in Spain, Madeira, etc.
Description---Both common and official names are derived from the Sanskrit
nagaranga through the Arabic naranj.
It is a small tree with a smooth, greyishbrown bark and branches that spread
into a fairly regular hemisphere. The oval, alternate, evergreen leaves, 3 to 4
inches long, have sometimes a spine in the axil. They are glossy, dark green on
the upper side, paler beneath. The calyx is cup-shaped and the thick, fleshy
petals, five in number, are intensely white, and curl back.
The fruit is earth-shaped, a little rougher and darker than the common, sweet
orange: the flowers are more strongly scented and the glands in the rind are
concave instead of convex.
The first mention of oranges appears in the writings of Arabs, the time and
manner of their first cultivation in Europe being uncertain.
The small, immature fruits are sometimes used under the name of Orange berries
for flavouring Curaçoa. They are the size of a cherry and dark greyish-brown in
colour. Formerly an essence was extracted from them.
The peel is used both fresh and dried. Much is imported from Malta, cut more
thinly than that prepared in England.
In Grasse the blossoms are candied in large quantities.
Oil of petit grain is made from the leaves and young shoots.
The volatile oil of the bitter Orange peel is known as Oil of Bigarade, and
Sweet Orange oil as Oil of Portugal. For methods of extraction, see LEMON.
Orange oil is one of the most difficult to preserve, the most satisfactory
method being to add 10 per cent of its volume of olive oil.
The flowers yield by distillation an essential oil known as 'Neroli,' which
forms one of the chief constituents of Eau-de-Cologne. A pomade and an oil are
also obtained from them by maceration.
The oil from Sweet Orange blossoms is found in commerce under the name of 'Neroli
petalae.' Being far less fragrant it only fetches half the price of neroli oil
and on that account is frequently used to adulterate the true neroli oil.
The largest Bigarade-tree plantations are to be found in the South of France, in
Calabria and in Sicily. The centre of the industry of neroli oil is the South of
France, where the bitter Orange is extensively cultivated for that purpose
alone. The tree requires a dry soil with a southern aspect. It bears flowers
three years after grafting, increasing every year until it reaches its maximum,
when it is about twenty years old. The quantity depends on the age and
situation, a full-grown tree yielding on an average 50 to 60 lb. of blossoms.
One hundred Orange trees, at the age of ten years, will occupy nearly an acre of
land, and will produce during the season about 2,200 lb. of Orange flowers. The
flowering season is in May and the flowers are gathered two or three times a
week, after sunrise. When the autumn is mild and atmospheric conditions are
favourable, flowering takes place in October, and this supplementary harvest
lasts until January, or till a frosty morning stops the flowering. These autumn
flowers have much less perfume than those of the spring and the custom is to
value them at only one-half the price of May flowers. The Bitter Orange and
Edible Orange trees bear a great resemblance to each other, but their
leaf-stalks show a marked difference, that of the Bitter Orange being broadened
out in the shape of a heart. The yield of oil is greatly influenced by the
temperature and atmospheric conditions prevailing at the time of gathering. In
warm weather it may amount to as much as 1,400 grams per 100 kilogrammes of
flowers, but under adverse conditions, such as damp, cool and changeable
weather, considerable diminution is experienced. Generally the largest yields
are obtained at the end of the flowering season, on account of the warmer
temperature.
The method most followed for extraction of the oil is by distillation, which
yields a higher percentage of oil from the flowers than maceration or absorption
in fats and volatile solvents. The flowers are distilled immediately after
gathering, the essential oil rising to the surface of the distillate is drawn
off, while the aqueous portion is sold as 'Orange Flower Water.' Orange flower
water is being increasingly used in France by biscuit-makers to give crispness
to their products, and some of the English biscuit-makers have also adopted it
for this purpose.
There is a marked difference in the scent of the oils obtained by the different
processes. Neroli obtained by distillation has quite a different odour from the
fresh Orange flower; the oils obtained by solvents and by maceration and
enfleurage are truest to the scent of the natural flower. From 100 kilogrammes
of flowers 1,000 grams of oil are obtained; by volatile solvents, 600 grams; by
maceration, 400 grams; and by enfleurage, only about 100 grams of oil.
Orange Flower Oil as obtained from pomatum, slightly modified with other
extracts, can be employed to make 'Sweet Pea' and 'Magnolia' perfumes, the
natural odours of which it slightly resembles.
The use of Orange-blossom as a bridal decoration is neither long-established nor
indigenous, as it was introduced into this country from France only about a
hundred years ago.
Constituents---The peel of var. Bigaradia contains volatile oil, three
glucosides, hesperidin, isohesperidin, an amorphous bitter principle,
Aurantiamarin, aurantiamaric acid, resin, etc.
The ethyl ether of -naphthol, under the name of nerolin, is an artificial oil of
neroli, said to be ten times as strong.
Oil of Orange Flowers is:
'soluble in an equal volume of alcohol, the solution having a violet
fluorescence and a neutral reaction to litmus paper. The specific gravity is
0.868 to 0.880 at 25 degrees C. (77 degrees F.). When agitated with a
concentrated solution of sodium bisulphate it assumes a permanent purple-red
colour.'
It must not be coloured by sulphuretted hydrogen.
Oil of Sweet Orange Peel contains at least 90 per cent o-limonene, the remaining
10 per cent being the odorous constituents, citral, citronellal, etc. It is a
yellow liquid with the specific gravity 0.842 to 0.846 at 25 degrees C. (77
degrees F.).
Oil of Bitter Orange Peel, a pale yellow liquid, is soluble in four volumes of
alcohol, the solution being neutral to litmus paper. The specific gravity is
0.842 to 0.848 at 25 degrees C. (77 degrees F.). The odour is more delicate than
that of the Sweet Orange.
Fuming nitric acid gives a dark green colour to sweet peel and a brown to the
bitter.
Medicinal Action and Uses---The oil is used chiefly as a flavouring agent, but
may be used in the same way as oil of turpentine in chronic bronchitis. It is
non-irritant to the kidneys and pleasant to take.
On the Continent an infusion of dried flowers is used as a mild nervous
stimulant.
The powdered Bitter Orange peel should be dried over freshly-burnt lime. For
flavouring, the sweet peel is better, and as a tonic, that of the Seville or
Bigaradia is preferred.
A syrup and an elixir are used for flavouring, and a wine as a vehicle for
medicines.
The compound wine is too dangerous as an intoxicant, being mixed with absinthium,
to be recommended as a tonic.
---Preparations of Bitter Orange---Syrup, B.P., 1/2 to 1 drachm. Tincture, B.P.
and U.S.P., 1/2 to 1 drachm. Infusion of Orange, B.P., 4 to 8 drachms. Infusion
of Orange Compound, B.P., 4 to 8 drachms. Compound spirit, U.S.P., 1 to 2
drachms. Syrup, B.P., 1/2 to 1 drachm. Wine, B.P., a wineglassful.
---Preparations of Sweet Orange---Syrup, B.P. and U.S.P., 1/2 to 1 drachm.
Tincture, U.S.P., 1/2 to 1 drachm.
Lemon
Citrus limon
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Description
Origin and Distribution
Varieties
Climate
Soil
Propagation
Culture
Harvesting and Handling
Yield
Storage
Pests and Diseases
Food Uses
Toxicity
Other Uses
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The leading acid citrus fruit, because of its very appealing color, odor and
flavor, the lemon, Citrus limon Burm. f. (syns. C. limonium Risso, C. limonia
Osbeck, C. medica var. limonium Brandis), is known in Italy as limone; in most
Spanish-speaking areas as limón, limón agria, limón real, or limón francés; in
German as limonen; in French as citrónnier; in Dutch as citroen. In Haiti, it is
limon France; in Puerto Rico, limon amarillo. In the Netherlands Antilles,
lamoentsji, or lamunchi, are locally applied to the lime, not to the lemon as
strangers suppose. The lemon is not grown there.
Several lemon-like fruits are domestically or commercially regarded as lemons
wherever they are grown and, accordingly, must be discussed under this heading.
These include: Rough lemon (C. jambhiri Lush.), Sweet lemon (C. limetta Risso),
'Meyer' (lemon X mandarin hybrid); 'Perrine' (lime X lemon hybrid); 'Ponderosa'
(presumed lemon X citron hybrid), qq.v. under "Varieties".
Plate XX: MEYER LEMON, possibly Citrus limon × C. reticulata
Description
The true lemon tree reaches 10 to 20 ft (3-6 m) in height and usually has sharp
thorns on the twigs. The alternate leaves, reddish when young, become dark-green
above, light-green below; are oblong, elliptic or long-ovate, 2 1/2 to 4 1/2 in
(6.25-11.25 cm) long, finely toothed, with slender wings on the petioles. The
mildly fragrant flowers may be solitary or there may be 2 or more clustered in
the leaf axils. Buds are reddish; the opened flowers have 4 or 5 petals 3/4 in
(2 cm) long, white on the upper surface (inside), purplish beneath (outside),
and 20-40 more or less united stamens with yellow anthers. The fruit is oval
with a nipple-like protuberance at the apex; 2 3/4 to 4 3/4 in (7 -12 cm) long;
the peel is usually light-yellow though some lemons are variegated with
longitudinal stripes of green and yellow or white; it is aromatic, dotted with
oil glands; 1/4 to 3/8 in (6-10 mm) thick; pulp is pale-yellow, in 8 to 10
segments, juicy, acid. Some fruits are seedless, most have a few seeds, elliptic
or ovate, pointed, smooth, 3/8 in (9.5 mm) long, white inside.
Origin and Distribution
The true home of the lemon is unknown, though some have linked it to
northwestern India. It is supposed to have been introduced into southern Italy
in 200 A.D. and to have been cultivated in Iraq and Egypt by 700 A.D. It reached
Sicily before 1000 and China between 760 and 1297 A.D. Arabs distributed it
widely in the Mediterranean region between 1000 and 1150 A.D. It was prized for
its medicinal virtues in the palace of the Sultan of Egypt and Syria in the
period 1174-1193 A.D. Christopher Columbus carried lemon seeds to Hispaniola in
1493. The Spaniards may have included lemons among the fruits they introduced to
St. Augustine. They were grown in California in the years 1751-1768. Lemons were
reported to be increasingly planted in northeastern Florida in 1839. Because of
heavy imports from Sicily, commercial culture in Florida and California was
begun soon after 1870 and grew to the point where 140,000 boxes were being
shipped out of Florida alone. The small Florida industry was set back by a
freeze in 1886, the susceptibility of the lemon to scab, and the unfavorable
climate for curing the fruit, and also competition from California. Following
the devastating freeze of 1894-95, commercial lemon culture was abandoned in
Florida. Not until 1953 was interest in lemon-growing revived in Central Florida
to take advantage of the demand for frozen concentrate and for natural
cold-press lemon oil. At that time, Florida was importing lemons from Italy for
processing. Plantings grew to 8,700 acres by 1975. Freezes caused 50% reduction
by 1980. Still, in 1984, Florida exported $2 million worth of lemons.
In the meantime, Arizona had developed lemon orchards, though on a smaller scale
than California. In the 1956-57 season, California produced 11 million gallons
(42 million liters) of frozen lemon concentrate while Florida's output was still
very small. California and Arizona became the leading sources of lemons in the
western hemisphere. In recent years, California has produced nearly double the
crop that can be profitably marketed fresh or processed. Foreign competition has
increased and many California growers have destroyed their lemon groves or
topworked the trees to oranges, but new cultural techniques making summer
production possible may reverse the trend.
Guatemala has in the past 2 decades developed commercial lemon culture,
primarily to produce the peel oil for its essential oil industry and secondarily
for the purpose of dehydrating the fruit and preparing a powder for
reconstituting into juice. Southern Mexico, too, is now a major grower of
lemons, also primarily for lemon peel oil. Lemons are rarely grown for the fresh
fruit market in Latin America. In South America, Argentina leads in lemon
culture with Chile a distant second. Among the world's leading lemon growers and
exporters are Italy, Spain, Greece, Turkey, Cyprus, Lebanon, South Africa and
Australia. Lemons can be grown only at medium and high elevations in the
Philippines.
Fig 41: Lemons: 'Ponderosa', perhaps a lemon X citron hybrid (left);
'Lisbon'-type commercial lemons (Citrus limon) (center); and rough lemon (C.
jambhiri) (right).
Varieties
With the resumption of lemon-growing in Florida, workers at the Citrus
Experiment Station, Lake Alfred, began a search for the most suitable cultivars,
whether in dooryards, or in the United States Department of Agriculture planting
at Orlovista, or the Lake Alfred collection. By late 1950, 200 selections had
been brought together from various parts of the United States. Of these, 40 were
budded onto 30-year-old grapefruit trees on rough lemon rootstock on the Minute
Maid property at Avon Park. Two selections grown elsewhere were included in the
studies-evaluation for thorniness, cold-and disease-susceptibility, sizes,
juiciness, flavor, number of segments and seeds, yields, and quality of peel
oil. The majority of the selections were judged undesirable; only a few showed
promise for processing and fresh fruit marketing purposes. For processing, 'Villafranca'
rated highest, followed by 'Eustis', 'Bearss', 'Perkin' and 'Avon'. Any of
these, properly harvested and cured would be suitable for marketing fresh.
Libby, McNeil & Libby, when planning for their lemon orchard at Babson Park,
Florida, about 1948, tested varieties from all major lemon-producing areas of
the world and chose 'Bearss' as rating highest in quality and quantity of juice,
which was their chief concern at the time. In 1960, they added marketing of the
fresh fruit and found the 'Bearss' equally desirable for this purpose.
The following are brief descriptions of most of the better known cultivars of
true lemons and of lemon-like fruits that are accepted as lemons in home or
commercial usage, and a few of the lesser-known.
'Armstrong' ('Armstrong Seedless')–a sport discovered in a private grove at
Riverside, California, about 1909. Patented in 1936 by Armstrong Nurseries.
Resembles 'Eureka' except that it usually bears seedless or near-seedless
fruits. If planted among other lemon trees will occasionally have a few seeds.
'Avon'–first noticed as a budded tree in Arcadia, Florida. A budded tree
propagated from the original specimen around 1934 was planted in the Alpine
Grove in Avon Park; it produced heavy crops of fruits highly suitable for frozen
concentrate. It, therefore, became the source of budwood for commercial
propagation by Ward's Nursery beginning in 1940.
'Bearss' ('Sicily', but not the original introduction by Gen. Sanford in 1875,
which has disappeared)–a seedling believed to have been planted in 1892,
discovered in the Bearss grove near Lutz, Florida, about 1952. Closely resembles
'Lisbon'. It is highly susceptible to scab and greasy spot and oil spotting. The
tree is vigorous and tends to produce too many water sprouts. Nevertheless, it
has been propagated commercially by Libby, McNeill & Libby since 1953 because
the peel is rich in oil. It constitutes 20% of Brazil's lemon/lime crop. ,
'Berna' ('Bernia', 'Vema', 'Vernia')–oval to broad-elliptic, with pronounced
nipple, short neck; peel somewhat rough, medium-thick, becoming thinner in
summer, tightly clinging. Seeds generally few or absent. Ripens mostly in
winter; fruits keep well on tree until summer but become too large. Tree is
vigorous, large, prolific. This is the leading cultivar of Spain and important
in Algeria and Morocco. It is too much like the 'Lisbon' to be of value in
California. In Florida, it has been found deficient in acid, low in juice, and
too subject to scab.
'Eureka'–originated from seed taken from an Italian lemon (probably the 'Lunario')
and planted in Los Angeles in 1858; selected in 1877 and budwood propagated by
Thomas Garey who named it 'Garey's Eureka'. The fruit is elliptic to oblong or
rarely obovate, with moderately protruding nipple at apex, a low collar at the
base; peel yellow, longitudinally ridged, slightly rough because of sunken oil
glands, medium-thick, tightly clinging; pulp greenish-yellow, in about 10
segments, fine-grained, tender, juicy, very acid. Fruits often borne in large
terminal clusters unprotected by the foliage. Bears all year but mostly late
winter, spring and early summer when the demand for lemons is high. Tree of
medium size, almost thornless, early-bearing, prolific; not especially vigorous,
cold-sensitive, not insect-resistant; relatively short-lived. Not suitable for
Florida. Grown commercially in Israel. One of the 2 leading cultivars of
California, though now being superseded by clonal selections with more vigor,
e.g., 'Allen', 'Cascade', 'Cook', and 'Ross'. 'Lambert Eureka' is a chance
seedling found in 1940 on the property of Horace Lambert in New South Wales. It
is vigorous and productive.
'Femminello Ovale'–one of the oldest Italian varieties; short-elliptic with low,
blunt nipple; slightly necked or rounded at base; of medium size; peel yellow,
finely pitted, medium-smooth, medium-thick, tightly clinging; pulp in about 10
segments, tender, juicy, very acid, of excellent quality, with few, mostly
undeveloped, seeds. Fruits all year but mainly in late winter and spring; ships
and stores well. The tree is almost thornless, medium-to very-vigorous, but
highly susceptible to mal secco disease. This is the leading cultivar in Italy,
accounting for 3/4 of the total lemon production, and 1/5 of the crop is
processed as single-strength juice.
'Genoa'–introduced into California from Genoa, Italy, in 1875. Almost identical
to 'Eureka'; ovoid or ovate-oblong with blunt nipple at apex; base rounded or
slightly narrowed; of medium size; peel yellow, medium-thick, tightly clinging;
pulp in 10-12 segments, melting, medium-juicy, with 29 to 51 seeds which are
light-brown within. Tree is shrubby, nearly trunk-less, spreading, very thorny,
cold-hardy. Grown commercially in India, Chile and Argentina.
'Harvey'–of unknown parentage; was found by Harvey Smith on the property of
George James in Clearwater, Florida. Fruit much like 'Eureka'. Tree highly
cold-tolerant, compatible with several rootstocks. Commercially propagated by
Glen St. Mary Nurseries Company, near Jacksonville, Florida, since 1943.
'Interdonato' ('Special')–a lemon X citron hybrid that originated on property of
a Colonel Interdonato, Sicily, around 1875; oblong, cylindrical, with conical,
pointed nipple at apex, short neck or collar at base; large; peel yellow,
smooth, glossy, thin, tightly clinging; pulp greenish-yellow, in 8 or 9
segments, crisp, juicy, very acid, faintly bitter. Very few seeds. Earliest in
season; mostly fall and early winter. Tree vigorous, usually thornless,
medium-resistant to mal secco; of medium yield; accounts for 5% of Italy's crop.
'Lisbon' (perhaps the same as 'Portugal' in Morocco and Algeria)–originated in
Portugal, possibly as a selection of 'Gallego'; reached Australia in 1824; first
catalogued in Massachusetts in 1843; introduced into California about 1849 and
catalogued there in 1853; introduced into California from Australia in 1874 and
again in 1875. Fruit almost identical to 'Eureka'; elliptical to oblong,
prominently nippled at apex, base faintly necked; peel yellow, barely rough,
faintly pitted, sometimes slightly ribbed, medium-thick, tightly clinging; pulp
pale greenish-yellow, in about 10 segments, fine-grained, tender, juicy, very
acid, with few or no seeds. Main crop in February, second crop in May. Fruit is
borne inside the canopy, sheltered from extremes of heat and cold. Tree large,
vigorous, thorny, prolific, resistant to cold, heat, wind. Not well adapted to
Florida. It is low-yielding and short-lived in India. Surpasses 'Eureka' in
California. Has given rise to a number of clonal selections, particularly
'Frost', originated by H. B. Frost at the Citrus Research Station, Riverside,
California in .1917 and released about 1950; also 'Prior Lisbon' and the more
vigorous 'Monroe Lisbon'.
'Meyer'–a hybrid, possibly lemon X mandarin orange; introduced into the United
States as S.P.I. #23028, by the agricultural explorer, Frank N. Meyer, who found
it growing as an ornamental pot-plant near Peking, China, in 1908; obovate,
elliptical or oblong, round at the base, occasionally faintly necked and
furrowed or lobed; apex rounded or with short nipple; of medium size, 2 1/4 to 3
in (5.7-7.5 cm) wide and 2 1/2 to 3 1/2 in (6.25-9 cm) high; peel light-orange
with numerous small oil glands, 1/8 to 1/4 in (3-6 mm) thick; pulp pale
orange-yellow, usually in 10 segments with tender walls, melting, juicy,
moderately acid with medium lemon flavor; seeds small, 8 to 12. Tends to be
everbearing but fruits mostly from December to April. Tree small, with few
thorns, prolific, cold-resistant; produces few water sprouts, and is only
moderately subject to greasy spot and oil spotting. It is easily and commonly
grown from cuttings. Does well on sweet orange and rough lemon rootstocks; is
not grafted onto sour orange because it is a carrier of a virulent strain of
tristeza. Grown for home use in California; in Florida, both for home use and to
some extent commercially for concentrate though the product must be enhanced by
the addition of peel oil from true lemons, since that from 'Meyer' peel is
deficient in flavoring properties. Has been fairly extensively planted in Texas
and in Queensland, Australia, and New Zealand.
'Monachello' (Moscatello')–suspected of being a lemon X citron hybrid;
elliptical, with small nipple and no neck, merely tapered at apex and base;
medium-small; peel yellow, smooth except for large, sunken oil glands, thin,
clinging very tightly; pulp in 10 segments, tender, not very juicy, not sharply
acid. Bears all year but mainly winter and spring. Tree not vigorous,
slow-growing, almost thornless, with abundant, large leaves; bears medium-well,
resistant to mal secco, and has been extensively planted in Italy in areas where
the disease is common.
'Nepali Oblong' (Assam', 'Pat Nebu')–originated in Assam; fruit resembles citron
in some aspects; long-elliptic to oblong-obovate, with wide, short nipple;
medium-large; peel greenish-yellow, smooth, glossy, medium-thick; pulp
greenish-yellow in 11 segments, fine-grained, very juicy, of medium acidity,
with few or no seeds. Everbearing. Tree large, vigorous, spreading,
medium-thorny, prolific; foliage resembles that of the citron. Commercial in
India.
'Nepali Round'–of Indian origin; round, without distinct nipple; juicy;
seedless. Tree large, vigorous, compact, nearly thornless, medium-prolific.
Successfully cultivated in South India.
'Perrine'–a Mexican lime X 'Genoa' lemon hybrid created by Dr. Walter Swingle
and colleagues in 1909, but still a fairly typical lemon; it is lemon-shaped,
with small nipple at apex, necked at base; of medium size; peel pale
lemon-yellow, smooth, slightly ridged, thin, tough; pulp pale greenish-yellow,
in 10 to 12 segments having thin walls; tender, very juicy, with slightly
lime-like flavor but acidity more like lemon; seeds usually 4 to 6, occasionally
as many as 12, long-pointed. Everbearing. Tree cold-sensitive but less so than
the lime; resistant to wither tip and scab but prone to gummosis and other bark
diseases. In the early 1930's, was extensively planted in southern Florida on
rough lemon rootstock, but no longer grown.
'Ponderosa' ('Wonder'; 'American Wonder')–a chance seedling, possibly of
lemon/citron parentage, grown by George Bowman, Hagerstown, Maryland around 1886
or 1887; appeared in nursery catalogs in 1900 and 1902; obovate, lumpy and
faintly ribbed, slightly necked at base; large, 3 1/2 to 4 1/8 in (9-11 cm)
wide, 3 1/2 to 4 3/4 in (9-12 cm) high; peel light orange-yellow, with
medium-large oil glands, flush or slightly depressed; 3/8 to 1/2 in (1-1.25 cm)
thick; pulp pale-green, in 10 to 13 segments with thick walls; juicy, acid;
seeds of medium size, 30 to 40 or more, brown within. Everbearing. Tree small,
moderately thorny; buds and flowers white or barely tinged with red-purple. More
sensitive to cold than true lemons. Grown for home use and as a curiosity in
California and Florida and in small-scale commercial plantings since 1948.
Rather widely cultivated as an indoor potted plant in temperate regions.
'Rosenberger'–a clone found in a grove of 'Lisbon' and 'Villafranca' trees at
Upland, California; was planted in the Rosenberger orchard and gained
recognition as a superior cultivar. Tree closely resembles that of 'Villafranca'.
Fruit is somewhat like 'Lisbon' but is shorter and broader and less tapered at
base. Tree vigorous and prolific. Became popular in California in the 1960's.
'Rough Lemon' ('Florida Rough'; French'; 'Mazoe'; Jamberi')–perhaps a lemon X
citron hybrid, but has been given the botanical name of C. jambhiri Lush.
Believed to have originated in northern India, where it grows wild; carried in
1498 or later by Portuguese explorers to southeastern Africa where it became
naturalized along the Mazoe River; soon taken to Europe, and brought by
Spaniards to the New World; is naturalized in the West Indies and Florida;
oblate, rounded or oval, base flat to distinctly necked, apex rounded with a
more or less sunken nipple; of medium size, averaging 2 3/4 in,(7 cm) wide, 2
1/2 (6.25 cm) high; peel lemon-yellow to orange-yellow, rough and irregular,
with large oil glands, often ribbed; 3/16 to 3/8 in (5-10 mm) thick; pulp
lemon-yellow, usually in 10 segments, medium-juicy, medium-acid, with moderate
lemon odor and flavor; seeds small, 10 to 15, brownish within. Reproduces true
from seeds, which are 96% to 100% nucellar. Tree large, very thorny; new growth
slightly tinged with red; buds and flowers with red-purple. The scant pulp and
juice limit the rough lemon to home use. It is appreciated as a dooryard fruit
tree in Hawaii and in other tropical and subtropical areas where better lemons
are not available. The tree has been of great importance as a rootstock for the
sweet orange, mandarin orange and grapefruit. It is not now used as a rootstock
for lemon in Florida because of its susceptibility to "blight" (young tree
decline). It is also prone to Alternaria leaf spot (A1ternaria citri) in the
nursery, to foot rot (Phytophthora parasitica). Incidence varies with the clone
and certain clones show significant resistance. In trials at Lake Alfred, 3
atypical clones showed immunity to leaf spot, while a typical rough lemon clone,
'Nelspruit 15', from South African seed, proved highly resistant to leaf spot
and also extremely cold tolerant.
'Santa Teresa'–an old tree discovered to be disease-free in a 'Fermminello Ovale'
orchard in Italy that had been devastated by mal secco. Budded trees from the
original specimen were being commonly planted in the 1960's wherever the disease
was prevalent in Italy.
Sweet Lemon (C. limetta Risso)–a general name for certain non-acid lemons or
limettas, favored in the Mediterranean region, In India, they are grown in the
Nilgiris, Malabar and other areas. The fruits are usually insipid, occasionally
subacid or acid. The seeds are white within and the tree is large, resembling
that of the orange. One cultivar, called 'Dorshapo' after the plant explorers,
Dorsett, Shamel and Popenoe, who introduced it from Brazil in 1914, resembles
the 'Eureka' in most respects except for the lack of acidity. Another, called 'Millsweet',
apparently was introduced into California from Mexico and planted in a mission
garden. It was reproduced at the old University of California Experiment Station
at Pomona. Neither is of any commercial value.
'Villafranca'–believed to have originated in Sicily; introduced into Sanford,
Florida, from Europe around 1875 and later into California. Closely resembles
'Eureka'; of medium size. Tree is more vigorous, larger, more densely foliaged,
and more thorny than 'Eureka' but becomes thornless with age. One strain is
everbearing; another fruits heavily in summer. This was the leading lemon
cultivar in Florida for many years; is cultivated commercially in Israel; is
low-yielding and short-lived in India. It is little grown in California but has
given rise to certain selections that are of importance, particularly 'Galligan
Lisbon' and 'Corona Foothill Eureka'.
Fig. 42: Flowers of the lemon (Citrus limon) are larger and showier than those
of the orange.
Climate
Because of its more or less continuous state of growth, the lemon is more
sensitive to cold than the orange and less able to recover from cold injury. The
tree is defoliated at 22º to 24º F (-5.56º-4.44º C). A temperature drop to 20º F
(-6.67º C) will severely damage the wood unless there has been a fortnight of
near-freezing weather to slow down growth. Flowers and young fruits are killed
by 29º F (-1.67º C) and nearly mature fruits are badly damaged below 28º F
(-2.22º C). On the other hand, the lemon attains best quality in coastal areas
with summers too cool for proper ripening of oranges and grapefruit. Therefore,
the lemon has a relatively limited climatic range. In Florida, lemons are
produced commercially as far north as Ft. Pierce on the East Coast and Ruskin on
the West Coast. The 'Meyer' lemon, as a dooryard tree, can be grown wherever
oranges thrive, even as far west as Pensacola.
The fruits are scarred and the tree readily defoliated by winds, and benefit by
the protection of windbreaks.
Lemons are grown in both dry and humid atmospheres, the latter being a
disadvantage mainly in the processes of curing and storing. Over a large
lemon-growing region in California, annual rainfall varies from 25 to 125 cm. In
long, dry periods, the lemon must be irrigated.
Soil
The lemon tree has the reputation of tolerating very infertile, very poor soil.
In Florida, groves are mostly on sand. In California, excellent growth is
maintained on silty clay loam of high water-holding capacity. In Guatemala,
recommended soils are sand, clay and sandy-clay-deep, with high permeability and
good drainage. Black soils are also suitable if not lying over calcareous
subsoil. Ph should be between 5.5 and 6.5. If acidity is high, it is necessary
to apply lime to achieve the optimum level.
Propagation
The rough lemon is widely grown from seed. The 'Meyer' lemon is easily
reproduced by rooting large cuttings in the nursery and planting them directly
in the grove. They fruit 2 to 3 years sooner than budded trees and have a long
life, remaining in full production for over 30 years, perhaps much longer.
In Florida, commercial lemons have been budded onto 'rough lemon', sweet orange,
and 'Cleopatra' mandarin rootstocks. More recent practices are the utilization
of sour orange, Volkamer lemon (C. volkameriana), and alemow (C. macrophylla
Wester, an old Philippine lemon/ pummelo hybrid). The latter is employed in
California on soils containing an excess of soluble salts and boron. If
citranges are used as rootstocks for 'Eureka', bud union crease will kill the
tree.
Culture
Lemon trees should be spaced 25 ft (7.6 in) apart each way. If crowded or
"hedged", production declines. The trees must be pruned when young and kept
below 10 or 12 ft (3-3.6 m) in height. They are cut back severely after 12 years
or replaced. Weeds must be controlled but lemon trees are very sensitive to
herbicides.
In Florida, fertilizing may be done 3 times a year between mid-November and the
end of April, at the gradually increasing rate of 4 to 10 lbs (1.8-4.5 kg) per
tree up to an age of 50 years. Nitrogen and potash are given in equal amounts
under normal soil conditions. A nutritional spray with copper added is applied
after spring bloom. Fertilizer and irrigation programs should be varied
according to the desired goal: fresh fruit marketing or processing. High
nitrogen steps up yield and peel oil content but also results in more scab
infection and poor curing. Potash increases acidity. Heavy irrigation increases
yield and peel oil, scab infection, size of fruit and accelerates maturity.
In California, foliar spraying of urea is preferred over ground application of
nitrogen which can lead to accumulations of salts and also contamination of
groundwater. Leaf analyses are made to determine the nitrogen requirements of
each cultivar for maximum yield. 'Eureka', in a 6-year test, showed no response
to increased levels of nitrogen. In New Zealand, mature trees (15 to 20 years
old) are given 25 to 30 lbs (11.3-13.6 kg) of complete mixed fertilizer
annually, also heavy dressings of organic manure or mulch.
In Sicily, growers have, for over 50 years, made a practice of withholding water
in summer-for 35 to 60 days-until the trees begin to wilt. Then the trees are
heavily irrigated and given high nitrogen fertilizer which induces a second
bloom in August or early September, producing a crop the following summer when
lemons are scarce and prices are high. This system, called the "Verdelli
process", was adopted on a little over 1,000 acres (405 ha) in California in
1983. Adequate bloom did not occur on sandy or shallow soils, but 80% of the
plantings on gradually dehydrating, fine-textured soil bloomed well. Nearly $3
million was expected from this extra crop of summer lemons in the Central Valley
and the Riverside area in 1984. New horticultural techniques are needed to
overcome the handicaps of higher use of fertilizer, increased insect and fungus
problems, effects of moisture stress on fruit quality, and low temperature
hazard to immature fruits in winter.
In 1965, a team of California horticulturists initiated experimental trellis
culture of 'Prior Lisbon' lemon on C. macrophylla rootstock. It was found that
the labor of training, and repeated pruning either manually or by machine
hedging and topping, was excessive and uneconomic.
Guatemalan and Mexican growers interplant short-term crops such as beans,
cassava, yautía (Xanthosoma), in the rainy season, and tomatoes and peppers
during the winter when the lemon trees will be irrigated and fertilized.
Harvesting and Handling
The marketability of lemons depends on the stage at which they are picked.
Italian lemons for export are harvested as early as possible and are naturally
"cured" in transit. In early days, California and Florida lemons were allowed to
remain on the trees until they became too large. It was realized that early
picking is necessary and California and Arizona adopted the practices of picking
at any time after the fruits reach a 25 % juice content, and using rings to
gauge the commercially acceptable size, and repeated spot-picking with clippers.
Mechanical picking is impossible with lemons. The fruits are highly prone to oil
spotting (oleocellosis) and cannot be handled roughly nor picked wet.
Formerly, Florida lemons were picked from mid-July to October for shipping
fresh, and the balance in November was harvested for processing. Lemons under 2
1/8 in (5.4 cm) are too immature to attain proper quality for marketing and
fruits over 2 1/2 in (6.25 cm) are too large. Manual spot-picking has been
commonly practiced, but some producers have found it too costly, and are
harvesting the entire crop at one time and grading for fresh sale or processing
in the packing-house, discarding all undersized fruits. The lemons, after
sorting according to color, washing and coating with a fungicide and a thin
layer of wax are stored (cured) until ready for shipping.
Yield
Lemon tree yields vary considerably with the cultivar, the location and weather
conditions. A yield of 3 boxes per tree is commercially satisfactory in Florida.
In India, a 6-year-old tree bore 966 fruits and, at 9 years of age, had produced
a total of 3,173 fruits.
Storage
Florida's climate is unfavorable for long-term curing. It has been claimed that
a 10-day curing period is adequate and degreening of Florida fruit is not
needed. A major producer keeps the newly harvested fruits for 48 hours at 60º F
(15.56º C) and 95% humidity, then passes them through a pre-grading procedure to
eliminate all that are unusable. The usable fruits are then treated with
fungicide against stem-end rot and returned to the curing room. Those harvested
early in the season need 3 weeks to color-up, the last may require less than a
week. Finally, the fruits are washed, given a second fungicidal treatment,
dried, waxed and packed.
Generally, lemons are cured at 56º to 58º F (13.33º-14.4º C)and 85-90% relative
humidity. Green fruits may be held for 4 months or more, while the peel becomes
yellow and thinner, the pulp juicier (6-80%) and the proportion of soluble
solids higher (7-24%). Sometimes the degreening process is hastened by exposing
the fruit to ethylene gas, ethephon, or silane, but this practice tends to
stimulate decay, mainly through the shedding of the "button" (stem stub), the
absence of which allows entry of Diplodia natalensis, Phomopsis citri, or
Alternaria mycelium. Various auxins have been studied to determine which can be
applied before storage to prevent button loss without delaying degreening. In
1982, Israeli investigators reported that decay losses from degreening
procedures can be greatly reduced (from over 50% to 6.3%) by packaging the
fruits in 10 micrometer-thick high-density polyethylene. This treatment makes it
possible to store lemons with minimum damage for as long as 6 months.
In the past, New Zealand lemons for storage have been individually wrapped in
diphenyl-treated paper after washing and dipping in a 200 ppm solution of
2,4,5-T and then waxing. The fruits were marketable after storing for 4 months
at room temperature. Lemons can be kept for weeks in the home refrigerator if
placed in a jar with a tight-fitting lid to prevent loss of moisture.
Lemons for export from Florida to Hawaii and Arizona must be fumigated with
methyl bromide because of possible infestation by the Caribbean fruit fly. For
sale within the state, other methods must be employed.
Pests and Diseases
In Southeast Asia, many species of ants attack the root system and the farmer
times the opening of the water gates so as to force the ants to the surface of
the beds, where he burns them with fire.
One of the 3 most serious arthropod pests of the lemon and other citrus trees in
California is California red scale, Aonidiella aurantii. In the southern part of
the state it is under biological control but it requires applications of
pesticides in the San Joaquin Valley. In Florida, rust mites, purple mites and
purple scale may at times be troublesome but they are all controllable with
appropriate sprays.
Young lemon trees in California sometimes require protection from wild rabbits.
Diseases are the greater challenges. In Florida, the main lemon diseases are
scab (Elsinoe fawcetti) on fruit, leaves and twigs; anthracnose of fruit (stylar-end-rot),
leaves and twigs caused by both Colletotrichum gloeosporioides and Glomerella
cingulata; greasy spot (Mycosphaerella citri or Cercospora citri-grisea); and
gummosis (Diaporthe citri). The latter organism also causes melanose and
die-back, and stem-end rot. Stem-end rot may also arise from attack by
Botryosphaeria ribis and Diplodia natalensis.
Other lemon diseases recorded in Florida are branch knot (Sphaeropsis
tumefaciens), damping-off (Rhizoctonia solani), leaf spot (Mycosphaerella horii,
AIternaria citri, and Catenularia sp.; algal leaf spot or green scurf (Cephaleuros
virescens); tar spot (Cercospora gigantea); felt fungus (Septobasidium
pseudopedicellatum); charcoal root rot (Macrophomia phaseolina); root rot (Fusarium
oxysporum, Pythium ultimum, and Phytophthora parasitica; heart rot and wood rot
(Fomes applanatus and Ganoderma sessilis); crinkly leaf and exocortis viruses;
and green mold (Penicillium digitatum); blue mold (P. italicum); and pink mold
(P. roseum). In 1955, the lemon budwood certification program was begun to
provide virus-free stock for growers.
Red algae infests lemon trees and causes much dieback unless controlled with
copper fungicide in the summer. Zinc deficiency causes stunting of twigs,
reduced flowering, premature dropping of fruit, and yellow bands along the leaf
veins. Manganese deficiency is evidenced by interveinal chlorosis and subsequent
necrosis, shedding of leaves, flowers and young fruit. In India, fruit cracking
occurs when dry periods are followed by heavy rains. Cracking can be largely
avoided by frequent light irrigation during the dry period and early picking.
Stored lemons are subject to the stem-end rots and the molds listed above. The
albedo may show small dark sunken areas even though this defect is not visible
externally. Cultivars differ in their ability to resist decay.
Food Uses
Slices of lemon are served as a garnish on fish or meat or with iced or hot tea,
to be squeezed for the flavorful juice. In Colombia, lemon soup is made by
adding slices of lemon to dry bread roll that has been sautéed in shortening
until soft and then sieved. Sugar and a cup of wine are added and the mixture
brought to a boil, and then served.
Lemon juice, fresh, canned, concentrated and frozen, or dehydrated and powdered,
is primarily used for lemonade, in carbonated beverages, or other drinks. It is
also used for making pies and tarts, as a flavoring for cakes, cookies, cake
icings, puddings, sherbet, confectionery, preserves and pharmaceutical products.
A few drops of lemon juice, added to cream before whipping, gives stability to
the whipped cream.
Lemon peel can be candied at home and is preserved in brine and supplied to
manufacturers of confectionery and baked goods. It is the source of lemon oil,
pectin and citric acid. Lemon oil, often with terpenes and sesquiterpenes
removed, is added to frozen or otherwise processed lemon juice to enrich the
flavor. It is much employed as a flavoring for hard candies.