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Vegetable Crops–PLSC 451/551Lesson 22, Salad Crops

Instructor:Stephen L. LoveAberdeen R & E Center1693 S 2700 WAberdeen, ID 83210Phone: 397-4181 Fax: 397-4311Email: slove@uidaho.edu

Salad Crops

General Information

Wide range of species from many familiesWide range of species, from many families

Grown for large or succulent edible leaves

Usually eaten uncooked, but occasionally as potherbs

Production systems vary widely

Dandelion

Species: Taraxacum officinale (aster family)Origin: EurasiaOrigin: EurasiaMore commonly known as a weedy pestOften gathered rather than cultivated (subsistence)Some varieties exist-Europe, Asia (market gardens)Flowers and roots also edible

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Paracress

Species: Acmella oleracea (aster family)Origin: BrazilOrigin: BrazilMostly used in Brazil and MalaysiaSeldom cultivated (subsistence gathering)Adds sharp flavor to salads, moderates capsaicinFlower buds used to treat toothaches

Rocket Salad

Species: Eruca vesicaria (mustard family)Origin: Southern Europe/Western AsiaOrigin: Southern Europe/Western AsiaPartially domesticated, often cultivatedLeaves make a sharp-tasting addition to saladsFlowers are also edibleSeeds produce a hot-flavored oil

Coriander

Species: Coriandrum sativum (carrot family)Origin: Western AsiaOrigin: Western Asia Small-scale production worldwideProduction: from modern-intense (cilantro seed) to

market-garden/subsistence (salad coriander)Common in Asian and Mexican cuisineAnnual growth but harvested multiple times

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Parsley

Species:

Petroselinum crispum (carrot family)

Origin: Mediterranean regionOrigin: Mediterranean region

Traditionally used for medicinal purposes

Leaves used as garnish/flavoring, soups, stews

Biennial or perennial harvested multiple times

Small-scale modern production for processing, market-garden production for fresh use

Amaranth

Species: Amaranthus tricolor

Native of Central and South America

Greatest diversity in India

Mostly subsistence production

Leaves edible in uncooked salad dishes

One species important for seed grain (quinoa)

Basella

Basella

Species: Basella rubra

Native to tropical AsiaNative to tropical Asia

Perennial vine to 12 feet tall

Leaves edible in salads (tastes like spinach)

Pigment in leaves and fruit used as edible dye

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Purslane

Species: Portulaca oleracea

Native of India or Iran

Common weed throughout the world

Often gleaned from uncultivated sites

Some domesticated forms cultivated (subsistence)

Succulent leaves edible, high in iron

Borage

Species: Borago officinalis Origin: MediterraneanOrigin: MediterraneanFoliage, tender stems and flowers edibleSalad use in Germany, flavors pickles in PolandMost common use is for seed oilSubsistence or small market-garden productionGood companion plant to deter insect pests

Other Minor Salad Crops

Upland Cress (Barbara verna) – western EuropeGarden Cress (Lepidium sativum) - EuropeSalad Chervil (Anthriscus cerefolium) – Europe USSalad Chervil (Anthriscus cerefolium) – Europe, USAsiatic pennywort (Centella asiatica) - IndonesiaGarden sorrel (Rumex acetosa) – Europe, AfricaNew Zealand spinach (Tetragonia tetragonioides)Water cress (Nasturtium officinale) - worldwideCorn salad (Valerianella locusta) - Mediterranean

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Endive

Description

Species: Cichorium endiva (sunflower family)N i h M di iNative to the Mediterranean regionImportant salad crop in Europe, increasingly in U.S.Edible portion is a loose head of leavesMany types with broad, curled or fringed leavesCan be bitter and harsh, differential sensitivity in

humans

Chicory

DescriptionAlso known as French endive, witloof chicorySpecies: Cichorium intybus (endive Genus)N i h M di iNative to the Mediterranean regionImportant salad crop in Europe, some in U.S.Edible portion is apical bud, roots eaten in some

typesForcing commonly practiced (second-year growth of

biennial type forced the first year)

Spinach

Origin and domestication

Species: Spinacia oleracea (beet family)p p ( y)Native of southwest Asia (Iran)Cultivated for about 2000 yearsGrown in Europe around 1000 ADBrought to North America by European

settlers

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Spinach

Use and production

Traditionally a potherb, now important salad crop

Considered of high value nutritionally

Important in the U.S and some parts of Europe

Major producing states: California, Colorado, Texas, New Jersey, Maryland

Total U.S. production 15,000 acres

Spinach

Harvest and Storage

Fresh spinach hand harvested

whole plant pulled, trimmed

harvest done late day, less turgidity

Processed spinach machine harvested

cut at the top of the petiole, bulk handled

Cooled with crushed ice, generally not stored

Celery

Origin and domestication

Species: Apium graveolens (carrot family)

Biennial grown as an annual

Native to Mediterranean region, North to Sweden

Cultivated before 850 BC

First used for medicinal purposes

Domestication increased size, decreased bitterness

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Celery

Use and production

Edible portion is the leave petiole, roots are used and known as celeriac

Consumed raw or cooked in soups and stews

Important vegetable in North America and Europe

California, Texas, Michigan, Ohio major producers

U.S. total production 27,000 acres

Celery

Varieties

Green typesU h P l F d H kUtah, Pascal, Ford Hook

Self-blanching typesGolden Self Blanching, Sanford Superb

CeleriacPrague, Delicacy

Smallage (minimal use, few varieties)

Celery

Management techniques

Environmentally demanding crop

Mean temperatures 60-70 degrees

Sensitive to freezing

Bolts following cool temperatures (50 degrees)

Shallow rooted, requires irrigation

Heavy feeder, high use of N

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Celery

Management techniques

Slow seed germination (15 days minimum)g ( y )Exhibits thermodormancy above 75 degreesFar-red light helps eliminate thermodormancySeed often pelletedTransplanting often practiced to overcome

germination problems

Lettuce

Lettuce

Taxonomy

Family: Asteraceae (Compositae)Family: Asteraceae (Compositae)

family with 20,000 species, few cultivated

Genus and species: Lactuca sativa

Related species: sunflower, dandelion, globe artichoke, endive

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Lettuce

Taxonomy

SubspeciesSubspecies

capitata – head lettuce

crispa – leaf lettuce

longifolia – Cos or Romaine lettuce

aparagina – stem or asparagus lettuce

Lettuce

Origin and Domestication

Native to the Mediterranean regionWild i kl d i lWild types are prickly and contain latexGrown in Egypt as early as 4500 BCEarly use medicinal and for seed oilDomestication resulted in slow bolting, lack of

spines, non-shattering seed, large leavesHead lettuce first described in 1543

Latex production in wild types

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Lettuce

Importance

Most popular salad cropp p pIn U.S., value among vegetables second to

potatoesConsidered a pleasure foodHigh in vitamin A, calcium, ironLow in calories and other nutrients

Lettuce

World Production

World acreage 700 000 acresWorld acreage 700,000 acres

Grown throughout the temperate regions

Amenable to all production systems

Common subject for organic production

Lettuce

Consumer use

Used almost entirely as a raw vegetable aloneUsed almost entirely as a raw vegetable alone or in salads

Heavily used by the restaurant industry

Produced and marketed throughout the year

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Lettuce

Climate and soilsRequire a cool climate

optimum 70 degree day, 50 degree nightSeedlings resistant to moderate frostMaturation rate temperature dependentVarieties are mostly daylength neutral, but:

Long days encourage bolting under high temps

Lettuce

Stand EstablishmentMostly direct-seeded, thinnedPlanted shallow (light requirement) – ¼ in deepPlanted shallow (light requirement) ¼ in deepSoil must be well-worked, smoothCompacted soil severely limits emergence

Phosphoric or sulfuric acid – anticrustantsIrrigated regularly during germinationMulches commonly used

Thinned 10-12 in apart on raised, double beds (36 in)

Lettuce

Physiological problems

Tipburn – necrosis of inner leaf margins

local calcium deficiency, more N helps

Russet spotting – reddish spots on midrib

interaction of ethylene and temperature

avoid ethylene (lower than .5 ppm)

maintain temperatures at 32-35 degrees

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Lettuce

Physiological problems

Tipburn – necrosis of inner leaf margins

local calcium deficiency, more N helps

Russet spotting – reddish spots on midrib

interaction of ethylene and temperature

avoid ethylene (lower than .5 ppm)

maintain temperatures at 32-35 degrees

Lettuce

Production - Harvest

Harvest indicesHarvest indices

Head of adequate size

Head firm

Leaves green

No bolting

Lettuce

Production - Harvest

Multiple harvests (small production)

Hand harvested (machine assist)

Common to harvest, trim, pack in the field

Limits handling

Reduces injury

Eliminates waste disposal

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Lettuce

Handling and Storage

Field packed in marketable cartons

Vacuum cooled to <50 degrees within 1 hour

Not hydrocooled (pathogens)

Usually not stored

Can be at 33-34 degrees, 90-95% RH, 1-2 weeks

Not stored or shipped with ethylene producers