Vegetable Crops –PLSC 451/55 Lecture 13, Taro, Yam

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

Taro field

L to R: taro, yam, sweet potato, cassava

Taro

Also Known As:

Dasheen

Cocoyam

Kolocasi

Ocumo

Dalo

Taro plant (Dasheen)

Taro

Domestication

Probably originated in India or Southeast Asia

Taken to China and Japan - 2000 AD

Spread to Africa and South Pacific - 500 AD

Came to the Western Hemisphere with slaves

Yautia (Taro relative)

Domestication

Also called Tannia

Yautia is a related Arum species and is replacing Taro in many African countries

Native of tropical America

Species name: Xanthosoma sagittifolium

Very similar in appearance, culture, use

Taro plant

Taro corm

Taro

Production – Climate and soils

Tropical

Warm-season, very tender

Tolerates heavy, clay soils

Needs abundant water

Can withstand waterlogged soils

Optimal pH 6.0-7.0

Tolerates salty water, quick storm recovery

Taro

Production Systems

Very few large producers

(Partially mechanized)

Virtually no organic production

Most production on subsistence and small market farms

Taro

Production System - Dryland

Not ponded

Irrigated or planted in the dry season

Often intercropped in subsistence production

Herbicides commonly employed for weed control

Taro

Production System - Wetland

Ponded or flooded

Requires cheap, surplus water

Monoculture

Herbicides not required

TaroPropagation

Often propagated from a “huli”

Propagules commercially unavailable

Nurseries co-produced

Hand-planted or machine assisted

Taro

Harvest

Maturity indicated by leaf drop and yellowing

Harvest usually by hand

No post-harvest curing necessary

Store at 45-50 degrees

Can be stored for 18 weeks, 2 day shelf-life

Harvested taro, ready for market

Major Producing CountriesChina 1,320 mtNigeria 1,300Ghana 1,240Japan 330Papua New Guinea 220

Considered to be a staple crop in Africa

Taro

Consumer use

Fresh market

Boiled or baked

Processed

Chips, canned, frozen, dehydrated flour used for noodles, cakes and baby food

Making poi by mashing taro root

Poi made from taro root

Taro boiled with fish

Boiled taro in coconut milk

Thai desert made from taro, beans, and egg yolks

Taro

Taxonomy

Monocotyledon

Family: Araceae

Genus and species: Colocasia esculenta

Related species: calamus, Jack-in-the-pulpit

Yam (D. batatas)

Yam plant

Yam tubers

Yam

Taxonomy

Monocotyledon

Family: Dioscoraceae

Genus and species: Dioscorea (species)

Related species: 250 species of wild yams

Yam

Species used for cultivation

D. alata (greater yam) – SE Asia

D. batatas (Chinese yam) – China

D. rotunda (yellow yam) – Africa

D. esculenta (lesser yam) – SE Asia

D. bulbifera (aerial yam) – Africa

D. trifida (cush-cush) – Tropical America

Dioscorea alata (Greater yam) – most widely distributed

SE Asia

Dioscorea rotunda (Yellow yam) – greatest production

Africa

Dioscorea batatas (Chinese yam)

China

Dioscorea batatas (Chinese yam)

China

Dioscorea esculenta

(Lesser yam)

SE Asia

Dioscorea bulbifera (Aerial yam)

Africa

Dioscorea trifida (Cush-cush yam)

Tropical America

Major Producing Countries

Nigeria 27 mil mt

Ghana 4

Ivory Coast 3

Benin 2

Togo 0.5

Colombia 0.3

Yam

Domestication

Used for food in West Africa (probable area of origin) >50,000 years ago

Cultivated 3000 BC in West Africa and SE Asia

Yam

Use and importance

Important staple crop in Africa

Subsistence production systems

Considered to be an under-utilized crop

Very high in starch, protein, minerals

Yam

Consumer use

Fresh marketBaked, boiled, pounded, fried, dried and ground into flour

(Some types must be heavily processed -boiled, pounded and leached - to eliminate alkaloids)

African peanut and yam soup

Yam

Unusual compounds

Dioscorine – alkaloid in D. hispida and other yams, very poisonous (used as a pest poison)

Sapogenin – steroidal alkaloid used in the production of cortisone, progesterone, and other drugs

Yam

Production – Climate and soils

Tropical

Warm-season, very tender

Will not grow in temps <70 degrees

Needs abundant water

Requires a well-drained soil

Yam

Production

Propagated using “head” of tubers from the previous crop

Six mo to 2 yr growing seasonVines are staked and trained

Yam

Production constraints:

Quantity of tubers for seed (30% of production)

Quantity of labor to plant, stake, and harvest

Tubers are deep and harvest difficult

Influence on local culture

Celebration of harvest, rites to invoke success of a new crop year

Vanatu vine jumpers

Yam

Production – Diseases and Pests

Has very few natural pests

Yam

Production – Harvest and storage

Mostly hand harvested

Stored at 55-60 degrees

Chilling injury at <50 degrees

Ventilation essential

Stored for 6-8 months (ambient)

Yam storage

Jerusalem artichoke flower

Jerusalem artichoke tubers

Jerusalem Artichoke

Domestication

Native of North America – found wild in the midwest and northeast

Cultivated by the Indians prior to European migration

Taken to Europe where it is grown in dry climatesName derived from Italian girasole articocco

(sunflower edible)

Jerusalem Artichoke

Use and importance

Similar in appearance and size to Irish potato

Very limited usage

Storage carbohydrate in inulin (polymer of fructose), useful for diabetics

Cooked and eaten in similar manner to potato

Jerusalem Artichoke

Production

Production in specialty market gardens

Planted using tuber pieces

Planted in fall or very early spring

Relative easy to grow

Jerusalem Artichoke

Production - Misc.

Volunteers become weedyHarvested by hand or machineCareful handling necessary if storedStore at 32-36 degreesCan be stored for several months

Jerusalem artichoke field