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0015 Winter and oriental cultivars These types take

longer to mature. Radishes grow best in moisture-

retentive, rich sandy loam soils whilst heavier soils

often cause misshapen roots. They are normally har-

vested during the autumn until the onset of hard

frosts between 8 and 14 weeks after sowing. After

this radishes can be stored through the winter (typic-

ally for up to 6 months) using the same storage

conditions as for carrots.

Domestic and Industrial Uses

0016 Early-maturing radishes are eaten raw in salads,

whilst winter and oriental radishes are either eaten

raw or as a cooked vegetable, rather like turnips. The

very characteristic flavor is popular in Japan, the

Philippines, and Hawaii and roots are used to prepare

food products such as takuwan and cabaizaku.

Leaves and pods of some cultivars can be boiled

and eaten as a vegetable. Roots have been used medi-

cinally in the treatment of liver and gallbladder

complaints.

Food Value and Chemical Composition

0017 Pungent flavor is due to isothiocyanates. Radishes are

a good source of ascorbic acid (15–40 mg 100 g

1

); a

higher concentration is found in pink-skinned culti-

vars. Catechol has been reported to be present in the

red cultivars and flavinols have been detected in

minute quantities. Food value and chemical compos-

ition of raw red and white radishes are summarized

in Table 1.

See also: Storage Stability: Mechanisms of Degradation;

Parameters Affecting Storage Stability; Vegetables of

Temperate Climates: Carrot, Parsnip, and Beetroot;

Miscellaneous Root Crops; Stem and Other Vegetables

Further Reading

Anonymous (1980) Grower Guide No. 14: Swedes and

Turnips for the Fresh Market. London: Grower Books.

Benjanin LR, McGarry A and Gray D (1997) The root

vegetables; beet, carrot, parsnip and turnip. In: Wien

HC (ed.) The Physiology of Vegetable Crops. UK: CAB

International.

Hardy FS and Watson GD (1982) The Complete Guide to

Vegetable Growing. London: Frederick Muller.

Holland B, Unwin ID and Buss DH (1991) Vegetables,

Herbs and Spices: Fifth Supplement to McCance &

Widdowson’s The Composition of Foods. London:

HMSO.

Kay DE (1973) Tropical Products Institute Crop and

Product Digest No. 2: Root Crops. Tropical Products

Institute.

Masalkar DL and Salunkhe DK (1998) Other roots, tubers

and rhizomes. In: Salunkhe DK and Kadam SS (eds)

Handbook of Vegetable Science and Technology: Pro-

duction, Storage and Processing. New York: Marcel

Decker.

Oldham CH (1950) Vegetable Growers’ Guide. London:

Lockwood.

Shoemaker JS (1947) Vegetable Growing. New York:

Wiley.

Tindall HD (1968) Commercial Vegetable Growing.

Oxford: Oxford University Press.

Miscellaneous Root Crops

P Hadley, University of Reading, Whiteknights,

Reading, UK

R Fordham, Ludgvan, Cornwall, UK

Introduction

A number of commercially less important temperate

root crops exist. These are either grown as domestic

crops, or on a limited scale by specialist commercial

growers.

Salsify – Tragopogon porrifolius, Family

Compositae

0001Salsify (also known as white oyster, vegetable oyster,

or oyster plant because of its oyster-like flavor) is a

root crop that is little known by general consumers. It

therefore has little importance commercially and is

only produced by specialist growers. The root is long

and tapering (20–30 cm long and 2.5–5 cm in diam-

eter), with a creamy white skin and a pale yellowish

flesh. The leaves are long and grass-like and have a

grayish-green color. It is favored as a winter vege-

table. Large purple flower heads are produced in the

second year. The flowers can be eaten if they are cut

before they get too woody.

Handling and Storage

0002Salsify is usually sown at the end of March in the UK

and roots can be harvested from the middle of Octo-

ber onwards. A long growing season is required in

order to produce large roots. A sandy loam or peat

soil with good water retention provides the best

growing conditions. Salsify is winter-hardy and can

withstand freezing conditions; indeed, it is suggested

that freezing can improve the oyster-like flavor.

Salsify is treated in the same way as parsnips and

can be stored in clamps or can be left in the ground

to be lifted as required. It is possible to extend the

storage period using controlled-atmosphere storage

5948 VEGETABLES OF TEMPERATE CLIMATES/Miscellaneous Root Crops

with the temperature maintained at 0



C, carbon

dioxide at 3%, and oxygen at 3%. High humidity is

essential to prevent shriveling. In the spring the

unlifted roots develop young and succulent shoots

known as chards.

Food Value and Chemical Composition

0003 Salsify has a similar nutritive value to parsnips but

has a lower calorific value (40 cal 100 g

1

)andis

valued as a source of fiber. It is low in sodium, its

vitamin content is low; it is low in fat and cholesterol-

free. Food value and chemical composition of raw

salsify are summarized in Table 1.

Celeriac –

Apium graveolens

, Family

Unbelliferae

0004 Celeriac is also known as turnip-rooted celery or

knob celery. It belongs to the same species as celery;

however, in this case the wild ancestor has been bred

to produce a ‘root’ that resembles a turnip. Celeriac is

not a true root but is a stem which has developed with

a large mass measuring up to 15 cm in diameter. It is

produced half in the ground and half above, and from

this a rosette of leaves is produced with a fibrous root

system produced below. The roots have a cream-

colored flesh with a characteristic celery flavor. The

foliage resembles that of celery but is coarse and not

edible.

Handling and Storage

0005 Cultivation of the crop is very similar to that of celery,

except that plants are not earthed up during the

growing season. As with celery, it cannot tolerate

drought conditions, although it can be grown success-

fully on a wide range of soil types providing that they

are free-draining. It can tolerate heavier soils than

celery. Celeriac is usually transplanted as the seeds

are too small to direct-drill. The crop is usually

sown in greenhouse conditions planted in the spring

(typically early to mid April in the UK) and is ready to

harvest by the middle of September onwards. Like

celery, it is a heavy feeder and responds well to

bulky organic manures. Roots are usually lifted

early in October and stored in dry, cool conditions

until required. Roots can remain in the field if soil is

drawn up around them or, alternatively, the crop is

covered with straw in mid-October to provide

some winter protection. Roots can then be lifted as

required.

Domestic and Industrial Uses

0006 Celeriac is peeled and can be boiled and served as a

hot vegetable or served cold in salads.

Food Value and Chemical Composition

0007Food value and chemical composition of raw celariac

are summarized in Table 1.

Scorzonera –

Scorzonera hispanica

0008Scorzonera (also known as black salsify or Spanish

salsify) and salsify are usually classed together be-

cause their roots have the same root shape and flesh

color. However, taxonomically they are unrelated.

The skin color of the root of scorzonera is dark purp-

lish, whilst the leaves are broader and shorter than

those of salsify. However, crop treatment is similar,

tbl0001Table 1 Nutritional value and chemical composition of salsify,

celeriac, and Jerusalem artichoke. Values are based on 100 g

raw flesh

Salsify Celeriac Jerusalem

artichoke

Proximates

Water 83.3 g 88.8 g 80.2 g

Sugar 1.5 g 1.8 g 1.3 g

Starch 3.5 g 0.5 g Trace

Dietary fiber N 5.1 g N

Total nitrogen 0.22 g 0.20 g 0.25 g

Energy value (kcal) 27 18 41

Energy value (KJ) 113 73 207

Protein 1.3 g 1.2 g 1.6 g

Fat 0.3 g 0.4 g 0.1 g

Carbohydrate 10.2 g 2.3 g 10.6 g

Minerals

Na 5 mg 91 mg 3 mg

K 310 mg 460 mg 420 mg

Ca 42 mg 40 mg 30 mg

Mg 20 mg 21 mg 11 mg

P 42mg 63mg 33mg

Fe 0.9 mg 0.8 mg 0.4 mg

Cu 0.0.1 mg 0.04 mg 0.12 mg

Zn 0.2 mg 0.3 mg 0.1 mg

S 22mg 15mg 22mg

Cl 37 mg 22 mg 58 mg

Vitamins

Retinol 0 mg0mg0mg

Carotene 20 mg2mg20mg

Vitamin D 0 mg0mg0mg

Thiamin 0.06 mg 0.18 mg 0.10 mg

Riboflavin 0.01 mg 0.02 mg Trace

Niacin 0.2 mg 0.5 mg 0.9 mg

Vitamin C 1 mg 14 mg 2 mg

Vitamin E N N N

Vitamin B

0.07 mg 0.08 mg N

Vitamin B

0 mg0mg0mg

Folate 57 mg51mgN

Pantothenic acid N N N

Biotin N N N

Boiled in unsalted water.

N, data not available.

Reproduced from Holland B, Unwin ID and Buss DH (1991) Vegetables,

Herbs and Spices: Fifth Supplement to McCance & Widdowson’s The

Composition of Foods. London: HMSO, with permission.

VEGETABLES OF TEMPERATE CLIMATES/Miscellaneous Root Crops 5949

maturing in approximately 120 days, and it is pre-

pared for the table in a similar way. Although it is

usually grown as an annual to provide a winter root

vegetable, scorzonera can be left in the ground for a

second season. This will result in a larger root with-

out any apparent loss in quality. Scorzonera has simi-

lar storage requirements to salsify.

Domestic and Industrial Uses

0009 The root can be eaten as a cooked vegetable and the

leaves can be eaten in salads.

Food Value and Chemical Composition

0010 These are not available.

Hamburg Parsley –

Petroselinum crispum

Family Umbelliferae

0011 Hamburg parsley (also known as turnip-rooted pars-

ley) is a type of parsley in which the root, rather than

the shoot, has been developed as the harvestable part.

The white, parsnip-shaped roots which have a pars-

ley/celery flavor can be eaten raw or boiled. The

leaves can also be served like spinach. It is more

often grown as a domestic crop than grown commer-

cially. The crop needs a long growing season. Ham-

burg parsley is hardy and can withstand moderate

freezing conditions in the open. Roots may be left

in the ground or lifted and stored like carrot and

parsnip.

Domestic and Industrial Uses

0012 Hamburg parsley is typically peeled and eaten as a

boiled vegetable.

Food Value and Chemical Composition

0013 These are not available.

Jerusalem Artichoke –

Helianthus

tuberosus

L., Family Asteracea

0014 Jerusalem artichoke (also known as girasole, topi-

nambur, and sunchoke) has edible tuberous roots

which are fleshy and irregular in shape and possess a

somewhat nutty flavor. The plant is vigorous, with the

shoot growing to 3 m or more. It is a native of North

America where it was grown by American Indians. It

was introduced into France in the early seventeenth

century and later appeared in England, Holland, and

Italy. The name ‘girasole’ was given to this plant in

Italy and ‘Jerusalem’ is a corruption of this word. The

name artichoke was given to denote a similarity in

taste and flavor of the tuber to the globe artichoke. It

is now widely grown in temperate, subtropical, and

tropical areas, although it has never been very popular

and the area under cultivation is not extensive.

Handling and Storage

0015The crop is grown from sets which are small tubers or

pieces of tuber normally weighing approximately 60 g

with at least two to three eye buds. A typical spacing

would be 30–60 cm apart in rows 90–129 cm apart.

Jerusalem artichoke is frost-sensitive and requires at

least 125 frost-free days to be grown successfully. The

crop normally reaches maturity in 18–24 weeks, al-

though early-maturing types can be harvested after

10–12 weeks. The crop can be harvested as soon as

the leaves begin to die back. The tubers can be lifted

by hand or by machine using a suitable elevator after

first cutting back the tops. Tubers are perishable but

can be stored at 0



C and 90–95% relative humidity

for 4–5 months. Yields average approximately 25–30

MT ha

1

Domestic and Industrial Uses

0016Tubers are boiled, baked, fried, or steamed and eaten

in much the same way as potatoes, but can also be

eaten raw in salads. Tubers are also grown for stock

feeding, particularly to pigs. The green tops can also

be used for stock feeding. Tubers can be utilized for

flour, as a source of fructose, and for the preparation

of 5-hydroxy-methyl-furfurol. They can also be used

as a source of industrial alcohol and for a beer-like

beverage.

Food Value and Chemical Composition

0017The principal storage carbohydrate present is inulin

rather than starch. Food value and chemical compos-

ition of boiled Jerusalem artichokes are summarised

in Table 1.

Chinese Artichoke –

Stachys tuberifa

Family Labiatae

0018Chinese artichoke is also known as crosnes and

kon loh. There are two other similar and closely

related species within the same genus (S. affinis and

S. sieboldii). The plant is a perennial grown for its

small edible tubers. It has rough, nettle-like leaves

and grows to a height of 30–45 cm. The tubers pro-

duced from its creeping root system are 5–8 cm long

and 1.5–2 cm in diameter, constricted at the inter-

nodes into rows of bead-like segments. It is a native

of the Far East and is cultivated in China and Japan.

Handling and Storage

0019Plants are propagated vegetatively from tubers. They

can be overwintered in cool temperate areas provid-

ing frosts are not too severe. Discoloration of tubers

following harvesting is reduced by storage in the dark

at low temperature and high humidity.

5950 VEGETABLES OF TEMPERATE CLIMATES/Miscellaneous Root Crops

Domestic and Industrial Uses

0020 Tubers have a taste similar to those of the larger

Jerusalem artichoke and may be roasted, boiled, or

fried.

Food Value and Chemical Composition

0021 The major storage carbohydrate in the tubers is tetra-

saccharide stachyose. Other nutritional data for this

crop are not available.

See also: Storage Stability: Mechanisms of Degradation;

Parameters Affecting Storage Stability; Vegetables of

Temperate Climates: Carrot, Parsnip, and Beetroot;

Swede, Turnip, and Radish; Stem and Other Vegetables

Further Reading

Holland B, Unwin ID and Buss DH (1991) Vegetables, Herbs

and Spices: Fifth Supplement to McCance & Widdow-

son’s The Composition of Foods. London: HMSO.

Huxley AJ, Griffiths M and Levy M (eds) (1992) The New

Royal Society Dictionary of Gardening, 4 vols. London:

MacMillan.

Kay DE (1973) Tropical Products Institute Crop and Product

Digest No. 2: Root Crops. Tropical Products Institute.

Masalkar DL and Salunkhe DK (1998) Other roots, tubers

and rhizomes. In: Salunkhe DK and Kadam SS (eds) Hand-

book of Vegetable Science and Technology: Production,

Storage and Processing.NewYork:MarcelDecker.

Oldham CH (1948) Brassica Crops and Allied Cruciferous

Crops. London: Lockwood.

Oldham CH (1950) Vegetable Growers’ Guide. London:

Lockwood.

Shoemaker JS (1947) Vegetable Growing. New York: Wiley.

Tindall HD (1968) Commercial Vegetable Growing.

Oxford: Oxford University Press.

Stem and Other Vegetables

R Fordham, Ludgvan, Penzance, Cornwall, UK

P Hadley, University of Reading, Whiteknights,

Reading, UK

Introduction

0001 In addition to the relatively small number of vegetable

groups grown on a large scale in the temperate regions

of the world, there are many lesser-known species

whose production is labor-intensive and/or whose

shelf-life is short, thus inhibiting large-scale commer-

cial exploitation. Many of these crops are confined to

home gardens. However, with increasing public taste

for novelty and growers prepared to innovate in order

to gain the potentially high market prices, such crops

are taking on an increased economic significance,

although global statistics are rarely available to quan-

tify their status. This article discusses a number of

such vegetables which are representative of a diverse

range of plant structures: stems (asparagus and

bamboo), leaf petioles (cardoon and seakale), flower

buds (globe artichokes), and fruits (okra).

Globe Artichoke (

Cynara scolymus

Family Compositae

0002The globe artichoke is a herbaceous perennial about

1.5 m tall. Its large erect leaves are gray-green and it

bears large thistle-like flowers about 10 cm in diam-

eter. The floral bracts have a sharp terminal spine,

although thornless cultivars are being selected for

commercial production. The globe artichoke is un-

known in the wild but probably derives from the

cardoon (C. carduncllus). It is grown primarily for

its immature flower buds, which are partly edible, but

young leaves may also be eaten as chards. Globe

artichokes were eaten fresh and preserved for year-

round use by the Romans centuries before Christ. It

was later rediscovered in Italy during the reign of the

Medicis, from where it was introduced into France

and, via Spain, to America. It is now grown widely in

southern Europe and Italy is a major producer. See

Table 1 for an estimation of world production and

leading producers.

Nutritional Value and Chemical Composition

0003The nutritional value and chemical composition of

the edible portion of the globe artichoke are indicated

in Table 2.

Handling and Storage

0004Propagation is either from seed or vegetatively from

suckers of selected cultivars. The crop is a short-term

tbl0001Table 1 Estimated world production of globe artichoke (Mt)

World 1 367 893

Italy 514 955

Spain 321 600

Egypt 87 923

Argentina 85 000

France 65 000

USA 49 580

Morocco 40 000

Algeria 39 000

China 30 000

Turkey 28 500

Chile 24 650

Greece 23 000

Source: FAO (2001) http://www.apps.fao.org.

VEGETABLES OF TEMPERATE CLIMATES/Stem and Other Vegetables 5951

perennial and it is usual to replant after approxi-

mately 3 years depending on soil and environmental

conditions. The crop grows well in temperate cli-

mates but cannot survive severe frosts. The flower

buds are harvested throughout the summer and

early crops can be produced under protection in glass-

houses or plastic tunnels.

0005 Globe artichokes do not store well but can be kept

for a few days in cold stores at 0



C and 95% relative

humidity.

Domestic and Industrial Use

000 6 Harvested flower buds are trimmed and boiled before

serving entire hot or cold, usually as an hors d’oeuvre.

The edible parts are the fleshy basal portions of

the bud scales or bracts and the heart or basal portion

of the flower. The ‘choke,’ consisting of immature

florets, is inedible and should be discarded. The

young shoots of the plant may also be forced and

blanched in the dark and used as a substitute for

celery in salads.

Asparagus (

Asparagus officinalis

), Family

Liliaceae

000 7 Asparagus is a dioecious perennial reaching a height

of about 1.5m, grown for its edible young shoots.

It originated in the eastern Mediterranean region and

occurs wild in maritime regions throughout Europe.

It has been used for over 2000 years, first as a medi-

cine and later as a vegetable. It is now widely grown

throughout the world and, although more suited to

the cooler temperate regions, it is also a valued export

crop for a number of warmer countries. The main

producing countries are listed in Table 3, along with

estimates of recent production figures.

Nutritional Value and Chemical Composition

0008Data on the nutritional value and chemical compos-

ition of the edible portion of asparagus shoots are

included in Table 2.

tbl0002 Table 2 Nutritionalvalueandchemicalcompositionofglobeartichoke,asparagus,bamboo,cardoon,andokra

NutrientUnitsArtichokeAsparagusBambooCardoonOkra

Proximates

Waterg84.94092.40091.00094.00089.580

EnergykJ197.00096.000113.00084.000138.000

Proteing3.2702.2802.6000.7002.000

Fatg0.1500.2000.3000.1000.100

Carbohydrateg10.5104.5405.2004.8907.630

Fiberg5.4002.1002.2001.6003.200

Minerals

Calciummg44.00021.00013.00070.00081.000

Ironmg1.2800.8700.5000.7000.800

Magnesiummg60.00018.0003.00042.00057.000

Phosphorusmg90.00056.00059.00023.00063.000

Potassiummg370.000273.000533.000400.000303.000

Sodiummg94.0002.0004.000170.0008.000

Vitamins

VitaminCmg11.70013.2004.0002.00021.100

Thiaminmg0.0720.1400.1500.0200.200

Riboflavinmg0.0660.1280.0700.0300.060

Niacinmg1.0461.1700.6000.3001.000

Pantothenicacidmg0.3380.1740.1610.0990.245

VitaminB

mg0.1160.1310.2400.0430.215

Folate mg68.000128.0007.10028.30087.800

VitaminAIU185.000583.00020.000120.000660.000

Valuesper100gedibleportion.

Source:USDA(2000)http://www.nal.usda.gov/fric/foodcomp.

tbl0003Table 3 Estimatedworldproductionofasparagus(Mt)

World4204338

China3508500

Peru180600

USA103060

Mexico55000

Spain51300

Germany50794

Morocco36000

Greece34000

Japan28700

Italy27143

France25000

Chile18800

Australia17000

Netherlands17000

Bulgaria12000

Source:FAO(2001)http://www.apps.fao.org.

5952 VEGETABLES OF TEMPERATE CLIMATES/Stem and Other Vegetables

Handling and Storage

0009 Plants are mainly propagated from seed but direct

seeding in the field is not recommended as germin-

ation is slow and emergence poor. For this reason

plants are usually established from 1-year-old crowns

raised by specialist propagators. As asparagus is dioe-

cious, seedlings will normally give rise to a mixture of

male and female plants, of which male plants are

more productive. For this reason plant breeders have

selected for all male cultivars, although the alterna-

tive approach of propagating selected male plants

by tissue culture is also practiced commercially. By

maintaining separate male and female lines through

tissue culture it is also possible to produce F1 hybrid

seed and a number of improved cultivars have been

introduced in this way.

0010 Field production is usually carried out from

1-year-old crowns established in the spring which

produce a canopy of fern-like leaves throughout the

growing season. This replenishes and builds up

the store of carbohydrates in the root system which

are necessary for regrowth of new shoots the

following year. In temperate regions the leaves die

back and the plants become dormant prior to

regrowth of shoots the following spring. The earliest

shoots are harvested for consumption while later-

produced ones are allowed to develop to reinstate a

photosynthetic canopy to provide carbohydrates

which are stored in the roots for the following year’s

crop. During the first year of production harvesting is

light in order for the plants to build up in size. Once a

plantation is established it can remain productive for

20–30 years, although commercially it is usual to

replant more frequently with improved stock. The

management of the crop requires a careful balance

to be made between harvesting and retaining suffi-

cient fern growth in the growing season. In

warmer regions of the world, fern growth may be

continuous and plants fail to achieve dormancy. It is

then necessary to regulate cropping by defoliating a

portion of an asparagus plantation which then initi-

ates a crop of new harvestable shoots, a number of

which must be left to reestablish new leaf growth. In

this way it is possible to harvest shoots throughout

the year, in contrast to temperate countries where

most of the crop is produced in the spring and early

summer.

0011 Crowns may be established either in ridges or flat

beds: the choice depends on a number of factors,

including soil drainage and the method of harvesting,

Shoots may be harvested either green or white. Shoots

are cut below ground level when about 25 cm long

either when only the tips are showing and the stem is

blanched or alternatively when a portion of the shoot

has developed above the soil surface and become

green. White asparagus production predominates in

Europe, South Africa, and Taiwan, whereas green

asparagus is more common in North America and

Australia. It is possible to advance cropping in cooler

regions by using plastic film covers which are re-

moved prior to harvesting.

0012Due to its high respiration rate, fresh asparagus has

a short storage life but this can be extended to around

3 weeks in cool stores set at approximately 2



Cand

high humidity, although there is danger of changes in

flavor and texture.

Domestic and Industrial Use

0013Young shoots are cooked by boiling and either served

entire or made into soup. The crop may also be pro-

cessed by freezing, canning, or dehydrating.

Bamboo Shoot – A Large Number of

Genera within the Family Graminae

0014The bamboos constitute a large number of species

(as many as 1000 within 90 genera) of the family

Graminae or grasses. These multipurpose perennials

include many of the world’s fastest-growing woody

plants. The mature shoots are used as timber for

construction purposes but the young blanched shoots

of many species are also harvested as vegetables. The

most important edible species are mainly natives of

China and include mousou-chiku (Phyllostachys edu-

lis), ku-chiku or mandake (P. bambusoides), and

P. dulcis. Other important genera include Dendroca-

lamus, Bambusa, and Sasa. Production statistics are

not readily available but the major producers include

China, Japan, Taiwan, and Thailand. New planta-

tions of D. asper and D. latiflorus have recently

been introduced in Australia.

Handling and Storage

0015Bamboo cultivation is in many ways similar to that of

asparagus in that the mature shoots provide photo-

synthates for the developing shoots which are har-

vested immature for consumption. The new shoots

are blanched by a covering of compost to exclude the

light and mature shoots are harvested at intervals,

providing a timber crop and stimulating further

shoot growth. Exposure of the young emerging shoots

to light can result in the photoactivated synthesis of

bitter and potentially toxic cyanogenic glycosides.

Plantings, which may be dedicated bamboo planta-

tions or intercropped with other crops, are established

vegetatively by division of the older crowns. Yields

may be as high as 10 000 kg ha

1

year

1

of edible

shoots.

VEGETABLES OF TEMPERATE CLIMATES/Stem and Other Vegetables 5953

Nutritional Value and Chemical Composition

001 6 Bamboo shoots form an important component of

Chinese cooking in which they contribute to the min-

eral and vitamin components of the diet. Estimates of

nutritional value and chemical composition for Phyl-

lostachys spp. are provided in Table 2.

Domestic and Industrial Use

001 7 Fresh bamboo shoots are cooked by boiling for

30 min to tenderize and remove bitter flavors caused

by cyanogenic glycosides. Precooked shoots are also

conserved by canning and drying.

Cardoon (

Cynara cardunculus

), Family

Compositae

001 8 Cardoon is a perennial crop, closely related to the

globe artichoke, grown for its fleshy petioles which

are sometimes blanched to render them more succu-

lent. It is a large plant, reaching a height of around

2 m, and is thistle-like in appearance. It was intro-

duced into the UK during the nineteenth century but

has never been grown on a large scale, although it is

more popular on the European continent.

Nutritional Value and Chemical Composition

001 9 Estimates of nutritional value and chemical compos-

ition of cardoon are included in Table 2. Shelf-life is

short but may be extended under cold-store condi-

tions of around 0



C and high relative humidity.

Domestic and Industrial Use

002 0 The crop is harvested in the autumn when the petioles

and thinly sliced hearts can be eaten raw in salads or

boiled in salt water until tender. Shoots may be

blanched prior to harvest by excluding light from

the lower portion of the stem with, for example,

black plastic.

Okra (

Abelmoschus esculentus

), Family

Malvaceae

002 1 Okra was formerly classified as Hibiscus esculentus.

Its center of origin was most likely West Africa

but transfer to parts of India and South-east Asia

occurred early on in the crop’s development. It is a

traditional vegetable of many tropical and subtrop-

ical countries but following its increasing popularity

its production has extended to more temperate areas

such as the southern USA. It is commonly known as

lady’s finger. Estimates of world production and

leading producers are shown in Table 4.

0022The species is very variable; commercial cultivars

are erect annuals which become woody at maturity.

The plant is primarily grown for it long, finger like

fruits which are harvested immature. The mature

seeds are relatively large and heavy (60 gper 100

seed) and show potential in various food supple-

ments.

Nutritional Value and Chemical Composition

0023Tender immature fruits provide dietary fiber, protein,

and vitamin C in human nutrition. As fruits mature

the increase in fiber content renders them unpalat-

able. The species is characterized by a high mucilage

content made up of acidic polysaccharides and having

viscous colloidal dispersion properties in water,

valued in soup and stew preparation. Okra seeds

contain 12–17% oil, mainly monounsaturated fatty

acids, and have potential in cereal-based diets due to

their high lysine level. They also show promise for use

as meat analogs as their protein concentrates and seed

flour are more soluble than commercial soya prod-

ucts. Nutritional value and chemical composition are

summarized in Table 2.

Handling and Storage

0024Okra requires a long growing period of relatively high

temperatures. It is sensitive to frosts and commercial

production is confined to summer months in subtrop-

ical and warmer parts of the temperate zone. Most

cultivars require short day lengths for floral initiation

and day-neutral selections are therefore required for

cultivation in temperate countries. Commercial selec-

tions are also available based on visual characters

tbl0004Table 4 Estimated world production of okra (Mt)

World 3 912 384

India 2 500 000

Nigeria 719 000

Ghana 150 000

Pakistan 109 000

Iraq 85 000

Egypt 76 000

Saudi Arabia 58 500

Benin 39 928

Mexico 36 000

Burkina Faso 26 000

Turkey 26 000

Yemen 19 100

Source:FAO(2001)http://www.apps.fao.org.

5954 VEGETABLES OF TEMPERATE CLIMATES/Stem and Other Vegetables

such as absence of spines and fruit color. The crop is

established from seed sown in situ as soon as spring

temperatures are favorable. Fruit production is not

synchronized and selective harvesting must be carried

out manually throughout the summer. Exudates from

the fruit surface and other plant parts can cause skin

inflammation.

0025 Fresh fruits have a short storage life and suffer

chilling damage at 6



C and below. Controlled-

atmosphere storage at 5% oxygen and 10% carbon

dioxide at 11



C and 90–93% relative humidity

extend shelf-life to 2 weeks.

Domestic and Industrial Use

0026 The fresh immature fruits may be boiled or fried or

used as a thickening agent in soups. Processing may

be by canning and freezing and cultivars are selected

for these outlets. Sun drying of fruit is conducted in

developing countries for off-season use.

Seakale (

Crambe maritime

), Family

Cruciferae

0027 Seakale is a perennial cultivated for its edible leaves

and young shoots. It has a delicate flavor when forced

and can be used as a substitute for asparagus. The

species is adapted to cool maritime climates and has

been collected from the wild since early times. Culti-

vation has been recorded since the early nineteenth

century, although on a relatively small scale. Trad-

itionally, seakale roots were lifted in the autumn and

forced in cold frames and covered with horse manure

topped with straw. Modern techniques involve raising

crowns under field conditions prior to forcing in the

dark under controlled environments of 15



C and high

humidity. The young succulent shoots are harvested

about 4 weeks later when they will have reached a

length of approximately 20 cm. They may be eaten

raw in salads or lightly boiled, as for asparagus.

Handling and Storage

0028 The crop is propagated by seed or vegetatively from

root cuttings, the latter resulting in earlier and more

uniform establishment. Once plants have built up

sufficient carbohydrate storage within its root system,

they are ready for forcing. This is achieved by

covering the dormant crowns in the autumn to pro-

duce a crop of young blanched shoots the following

spring. Following harvest, plants may remain in situ

and the process is repeated for the following year.

Earlier harvesting can be achieved by lifting crowns

and forcing under protection at warmer temperatures.

The young freshly harvested shoots do not store well.

Domestic and Industrial Use

0029Seakale has a unique nutty flavor and crisp texture. It

may be used raw in salads or the young shoots may be

boiled and used in a similar manner to asparagus.

See also: Storage Stability: Mechanisms of Degradation;

Parameters Affecting Storage Stability; Vegetables of

Temperate Climates: Carrot, Parsnip, and Beetroot;

Swede, Turnip, and Radish; Miscellaneous Root Crops

Further Reading

zyaman E (1997) Okra: botany and horticulture. In:

Janick J (ed.) Horticulture Reviews, vol. 21, pp. 41–72.

New York: John Wiley.

Hardy FS and Watson GD (1982) The Complete Guide to

Commercial Vegetable Growing. London: Frederick

Muller.

Huxley AJ, Griffiths M and Levy M (eds) (1992) The New

Royal Society Dictionary of Gardening, vols. 4 London:

MacMillan.

Nonnecke IL (1989) Vegetable Production. New York: AVI.

Rubatzky VE and Yamaguchi MAS (1997) World Vege-

tables – Principles and Nutritive Values, 2nd edn. Con-

necticut: AVI.

Salunkhe DK and Kadam SS (eds) (1998) Handbook of

Vegetable Science and Technology: Production, Com-

position, Storage and Processing. New York: Marcel

Dekker.

Splittstoesser WE (1990) Vegetable Growing Handbook –

Organic and Traditional Methods. New York: Van

Nostrand Reinhold.

Thompson HC and Kelly WC (1957) Vegetable Crops. New

York: McGraw-Hill.

Weichmann J (ed.) (1987) Postharvest Physiology of Vege-

tables. New York: Marcel Dekker.

VEGETABLES OF TEMPERATE CLIMATES/Stem and Other Vegetables 5955

VEGETABLES OF TROPICAL CLIMATES

Contents

Commercial and Dietary Importance

Root Crops of Uplands

Root Crops of Lowlands

Edible Aroids

Commercial and Dietary

Importance

S K Roy and A K Chakrabarti, Indian Agricultural

Research Institute, New Delhi, India

Background

0001 Tropical vegetables are many and varied. They con-

tain a large number of leafy and legume vegetables,

some of which are not only rich in proteins but also

rich in several vitamins, minerals, and fiber. Tropical

root vegetables are rich sources of carbohydrate, and

they serve as a staple food in many tropical countries.

They have a long shelf-life and have a good export

potentiality. Some tropical fruits, e.g., banana, jack

fruit, bread fruit, papaya, are consumed as vegetables

at the tender stage. These fruit vegetables are rich in

carbohydrate, phenolic compounds, and dietary fiber

as well as minerals and vitamins. Some of the tropical

vegetables are known to have curative properties

for certain ailments and are popular in traditional

medicine in several countries.

General Nutrient Composition

0002 Tropical vegetables include many roots and tubers

like sweet potato, cassava, taro, and yam, which are

rich in starch and serve as staple foods in many coun-

tries. Most leafy vegetables are rich in carotene (pro-

vitamin A), riboflavin (vitamin B

), and minerals.

It has been estimated that 100 g of tropical leafy

vegetables can provide 60–140 mg of ascorbic acid

(vitamin C), 100 mg of folic acid, 4–7 mg of iron and

200–400 mg of calcium. Consumption of 100 g of

leafy vegetables per day can supply 15% or more of

the total protein intake. Only 30 g of the leaves will be

sufficient to meet the requirements of vitamin A and

C. The B vitamins (thiamin, riboflavin, and niacin)

will increase by 15–30%, and the entire requirement

of folic acid will be met. (See Carotenoids: Physi-

ology.)

0003The nutrient composition of the major tropical

vegetables is listed in Tables 1 and 2 and is discussed

in detail in the section Importance of Specific Tropical

Vegetables. The essential amino acid profile of

selected, protein rich tropical leafy vegetables is

given in Table 3. Refer to individual nutrients.

Dietary and Commercial Importance

0004The general importance of vegetables in commerce

and diet, as discussed for temperate vegetables,

holds for the tropical vegetables also. Their commer-

cial value and importance in different diets are dis-

cussed in the section Importance of Specific Tropical

Vegetables. (See Vegetables of Temperate Climates:

Commercial and Dietary Importance.)

International Trade

0005Several tropical vegetables, such as sweet potato, taro,

yam, dried chilli, squash, and pumpkin, have a good

keeping quality. These vegetables are cultivated in the

tropical countries of Asia, Africa, and South America,

and are new to many people of Europe and North

America. These vegetables have added attractions in

those countries, and their export is growing steadily.

0006Some vegetables like the bitter gourd have a

therapeutic value and have been in use in traditional

medicine in India and China for centuries. Scientific

evidence that bitter gourd contains some phytoceuti-

cal chemicals that reduce blood sugar rapidly has

stimulated interest in Western countries and thus

increased its export potential.

0007Some vegetables like tomato, capsicum, cucumber,

and French bean are in great demand in Western

countries during the winter. The tropical and sub-

tropical countries that can grow these vegetables in

the open during winter have been able to meet

the demand to a great extent by exporting these

commodities. Those vegetables that are grown in the

open fetch a higher price than those grown under

protective cover because of their better quality

attributes. With the improvement in handling and

storage of vegetables by the introduction of modern

5956 VEGETABLES OF TROPICAL CLIMATES/Commercial and Dietary Importance

tbl0001 Table 1 Nutrient composition of tropical vegetables per 100-g edible portion

Crop Macronutrients Vitamins Minerals

Energy

(kcal)

Moisture

(g)

Protein

(g)

Fat

(g)

Carbohydrate

(g)

Thiamin

(mg)

Riboflavin

(mg)

Niacin

(mg)

Ascorbic

acid (mg)

Ca (mg) P (mg) Fe

(mg)

Amaranth 45 85.7 4.0 0.5 6.1 0.03 0.30 1.2 99 397 83 25.5

Basella 32 90.8 2.8 0.4 4.2 0.03 0.16 0.5 87 200 35 10.0

Bitter gourd 25 92.4 1.6 0.2 4.2 0.07 0.09 0.5 88 20 70 1.8

Bottle gourd 12 96.1 0.2 0.1 2.5 0.03 0.01 0.2 0 20 10 0.7

Bottle gourd leaves 39 87.9 2.3 0.7 6.1

Bread fruit 71 79.5 1.5 0.2 15.8 0.04 0.07 21 40 30 0.5

Brinjal 24 92.7 1.4 0.3 4.0 0.04 0.11 0.9 12 18 47 0.9

Cassava 157 59.4 0.7 0.2 38.1 0.05 0.10 0.3 25 50 40 0.9

Capsicum 22 93.4 1.2 0.2 4.0 0.06 0.06 0.5 128 9 22 0.7

Chinese cabbage 14 95.0 1.2 0.1 3.0 0.05 0.04 0.6 25 43 40 0.6

Cho cho 27 92.5 0.7 0.1 5.7 0 0.04 0.4 4 140 30 0.6

Cluster bean 16 81.0 3.2 1.4 10.8 0.09 0.03 0.6 49 130 57 4.5

Cowpea 48 85.3 3.5 0.2 8.1 0.07 0.09 0.9 14 72 59 2.5

Cowpea leaves 38 89.0 3.4 0.7 4.1 0.05 0.18 0.6 4 290 58 20.1

Cucumber 13 96.3 0.4 0.1 2.5 0.03 0 0.2 7 10 25 1.5

Drumstick 26 86.9 2.5 0.1 3.7 0.50 0.70 0.2 120 30 110 5.3

Drumstick leaves 92 75.9 6.7 1.7 12.5 0.06 0.05 0.8 220 440 70 7.0

Elephant-foot yam 79 78.7 1.2 0.1 18.4 0.06 0.07 0.7 0 50 34 0.6

Fenugreek leaves 49 86.1 4.4 0.9 6.0 0.04 0.31 0.8 52 395 51 16.5

French bean 32 90.1 1.9 0.2 7.1 0.08 0.11 0.5 19 56 44 0.8

Hyacinth bean 48 86.1 3.8 0.7 6.7 0.10 0.06 0.7 9 210 68 1.7

Indian squash 21 93.5 1.4 0.2 3.4 0.04 0.08 0.3 18 25 24 0.9

Ivy gourd 18 93.5 1.2 0.1 3.1 0.07 0.08 0.7 15 40 30 1.4

Jack fruit tender 51 84.0 2.6 0.3 9.4 0.05 0.04 0.2 14 30 40 1.7

Jute leaves 63 81.4 5.1 1.1 8.1 241 93

Kakrol 52 84.1 3.1 1.0 7.7 0.05 0.18 0.6 33 42 4.6

Lima bean 123 67.5 8.4 0.5 22.1 0.24 0.12 1.4 29 52 142 2.8

Lotus root 53 85.9 1.7 0.1 11.3 0.10 22 21 74 0.4

Muskmelon 17 95.2 0.3 0.2 3.5 0.11 0.08 0.3 26 32 14 1.4

Mustard leaves 34 89.8 4.0 0.6 3.2 0.03 0.22 0.8 33 155 26 16.3

Okra 35 89.6 1.9 0.2 6.4 0.07 0.10 0.6 13 66 56 1.5

Papaya green 27 92.0 0.7 0.2 5.7 0.01 0.01 0.1 12 28 40 0.9

Plantain 64 83.2 1.4 0.2 14.0 0.05 0.02 0.3 24 10 29 0.6

Pointed gourd 20 92.0 2.0 0.3 2.2 0.05 0.06 0.5 29 30 40 1.7

Pumpkin 25 92.6 1.4 0.1 4.6 0.06 0.04 0.5 2 10 30 0.7

Pumpkin leaves 57 81.9 4.4 0.8 7.9 10 392 112 2.1

Purslane 27 90.5 2.4 0.6 2.9 0.10 0.22 0.7 29 111 45 14.8

Ridge gourd 17 95.2 0.5 0.1 3.4 0.01 0.2 5 18 26 0.5

Snake gourd 18 94.6 0.5 0.3 3.3 0.04 0.06 0.3 0 26 20 0.3

Sponge gourd 18 93.2 1.2 0.2 2.9 0.02 0.06 0.4 0 36 19 1.1

Summer squash 17 94.8 0.5 0.1 3.5 0.02 Trace 0.4 18 10 30 0.6

Sweet potato 114 70.6 1.7 0.4 26.3 0.10 0.06 0.6 21 32 47 0.7

Sweet potato leaves 63 80.7 4.2 0.8 9.7 0.07 0.24 1.7 27 360 60 10.0

Taro 97 73.1 3.0 0.1 21.1 0.09 0.03 0.4 0 40 140 1.7

Taro leaf stalks 24 93.0 0.5 0.2 6.0 0.02 0.04 0.4 13 49 25 0.9

Tomato 22 93.5 1.1 0.2 4.7 0.06 0.04 0.7 23 13 27 0.5

Watermelon 26 92.6 0.5 0.2 6.4 0.03 0.03 0.2 7 7 10 0.5

Water spinach 28 90.3 2.9 0.4 3.1 0.05 0.13 0.6 37 110 46 3.9

Wax gourd 10 96.5 0.4 0.1 1.9 0.06 0.01 0.4 1 30 20 0.8

Winged bean 25 92.0 2.1 0.3 4.0

Yam 102 74.0 1.5 0.2 24.0 0.1 0.01 0.8 15 12 35 0.8

Source: FAO (1968) Food Composition Table for Use in Africa. Bethesda, MD: FAO and US Department of Education and Welfare; FAO (1972) Food

Composition Table for Use in East Asia. Rome: FAO; Gopalan C, Sastri BVR, Balasubramanian SC et al. (1999) Nutritive Value of Indian Foods. Hyderabad:

National Institute of Nutrition; Watt BK and Merrill AL (1963) Composition of Foods ^ Raw, Processed, Prepared. Agricultural Handbook No. 8. Washington, DC:

USDA.

VEGETABLES OF TROPICAL CLIMATES/Commercial and Dietary Importance 5957