Yams, Taro - CALS Projects Web

Vegetable Crops –PLSC 451/55
Lecture 13, Taro, Yam
Instructor:
Dr. Stephen L. Love
Aberdeen R & E Center
1693 S 2700 W
Aberdeen, ID 83210
Phone: 397-4181 Fax: 397-4311
Email: [email protected]
Taro
Also Known As:
Dasheen
Cocoyam
Kolocasi
Ocumo
Dalo
Taro plant (Dasheen)
1
Taro
Domestication
Probably originated in India or Southeast Asia
Taken to China and Japan - 2000 BC
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
2
Yautia vs Taro
Yautia
South American origin
Disease & pest resistant
Drought tolerant
Upland production only (not
flood tolerant)
Tolerates shade
Tall plants
Partial harvest (cormels)
Cormels consumed (corms
fed to animals)
Taro
Indian origin
Some disease & pest issues
Not drought tolerant
Lowland and upland production
Less shade tolerant
Moderate sized plants
Once-over harvest
Main corms consumed
Taro plant
Taro corm
3
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
Minimal or not fertilizer required
Taro
Production Systems
Very few large producers
(Partially mechanized)
Virtually no organic production
Most production on subsistence and small market farms
Taro
Production Scheme- upland
Nott ponded
N
d d
Requires a long rainy season, or
Irrigated in the dry season (not common)
Often intercropped in subsistence production
Herbicides commonly employed for weed control
4
Taro
Production Scheme- lowland
Ponded or flooded
Requires cheap, surplus water
Cool, oxygen-rich water
Monoculture
Herbicides not required
Taro
Comparison – upland vs lowland
Upland
Lowland
Lower yields
Weeds problematic
Wet-season production
Matures rapidly
High investment costs
Higher yields
No weed issues
Year-round production
Matures slowly
Low investment costs
Taro
Propagation
Often propagated from a “huli” (corms, corm pieces, suckers)
Propagules commercially unavailable
Nurseries co-produced with marketable crop
Hand-planted or machine assisted
5
Taro
Harvest/Storage
Maturity indicated by leaf drop and yellowing
Harvest usually by hand
No post-harvest curing necessary
Store at 45-50 degrees (seldom stored)
Can be stored for 18 weeks, 2 day shelf-life
Major Producing Countries
China
Nigeria
Ghana
Japan
Papua New Guinea
1,320 mt
1,300
1,240
330
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
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Taro
Toxicity
Most cultivars contain acrid components
Raphids + associated bitter compounds
(needle-like calcium oxalate crystals)
Cooking
usually breaks down the raphids (also
breaks down a common trypsin inhibitor)
Making poi by mashing
taro root
Taro
Taxonomy
Monocotyledon
Family: Araceae
Genus and species: Colocasia esculenta
Related species: calamus, Jack-in-the-pulpit
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Yam (D. batatas)
Yam plant
Yam tubers
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Yam
Taxonomy
Monocotyledon
Family: Dioscoraceae
Genus and species: Dioscorea spp.
Related: 250 species of wild yams
(both old & new world origin)
Yam
Primary cultivated
D. alata (greater yam) – SE Asia
D batatas (Chinese yam) – China
D.
D. rotunda (yellow yam) – Africa
D. esculenta (lesser yam) – SE Asia
D. bulbifera (aerial yam) – Africa
D. trifida (cush-cush) – Tropical America
SE Asia
Dioscorea alata (greater yam) – most widely distributed
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Africa
Dioscorea rotunda (yellow yam) – greatest production
China
Dioscorea batatas (Chinese yam)
China
Dioscorea batatas (Chinese yam)
10
SE Asia
Dioscorea esculenta
(lesser yam)
Africa
Dioscorea bulbifera (aerial yam)
Tropical America
Dioscorea trifida (cush-cush yam)
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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
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Yam
African peanut
and yam soup
Consumer use
Fresh market
Baked, boiled, pounded, fried, dried and
ground into flour
(Some types must be heavily processed boiled, pounded and leached - to eliminate
alkaloids)
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
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Yam
Propagation
Grown from the “head” of
tubers from previous crop
Possible to use vine cuttings
(slow)
Often planted during dry season
(dormant) to sprout later
Yam
Propagation
New procedure
“minisett” production
Yam
Production
Six month to 2 year growing
season depending on
species/conditions
Often intercropped
Vines are staked/trained
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Yam
Tuber Dormancy
Dormant when mature (harvest)
(
)
Dormancy lasts one to several
months
+Enhances storage capability
- Dictates one cycle per year of
planting and production
Yam
Production constraints:
Quantity of tubers for seed (30% of production)
Labor demands to plant, stake, and harvest
Tubers are deep and harvest difficult
Plants require high levels of fertility (1st slash
and burn crop or after legumes)
Yam
Production –
Diseases and
Pests
Has very few
natural pests
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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
Vanatu
vine
jumpers
Influence on local culture
Celebration of harvest, rites
to invoke success of a new
crop year
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