Thursday Lecture – Leaf, Stem and Root Crops

Reading: Textbook, Chapter 7

Baby carrots – a product of the “Soccer Mom” age

Baby carrots are produced by using specially bred forms that produce a long, thin storage root. The roots are carefully selected to eliminate discolored or malformed ones, and then are sliced into short pieces (2-3 inches). The pieces are further checked for color (they must have no hint of green) and are sent through a lathe device that smoothes the ends. The final product is ready to eat in a convenient form.

Quiz

Quiz

1.Name a vegetable for each category of what we actually eat:

petiole: entire leaf: inflorescence:

2. Where was the potato domesticated? What part of the plant do we eat?

Asparagus – Eat Your LiliesSee Fig. 7.25, p. 177

Onions – Allium cepaSee Fig. 7.27, p. 179

Leeks – Another AlliumSee Fig. 7.27, p. 179

Bulbs

Big budson short stems

Adventitious Roots

SucculentStorage Leaves

Stem

Corms: short fat underground stems

Corms

Rhizomes: simple underground stems

Hydrocotyle

Petiolesreach above

the sand

Nodes

Adventitious Roots

Apexof

Rhizome

Rhizomes

Tubers:swollen ends of

rhizomes

Bulb - onion

Tuber - potato

Corm - Crocus

STEMS

Irish PotatoSolanum tuberosum

The Amazing Spud- The potato is a short duration crop that produces a large amount of calories in a short period of time

- The potato produces more protein and calories per unit area per unit time and per unit of water than any other major plant food.

- The ratio of protein to calories, the quality of the protein and the high levels of vitamins and minerals are assets greatly needed in many countries.

Potatoes – South American Staple

Potatoes – South American Staple

Potatoes – South American Staple

Potatoes – South American Staple

Potatoes Travel to Europe

Frederick the Great encouraging peasants to grow more potatoes

Potatoes Travel to Europe

Frederick the Great encouraging peasants to grow more potatoes

Potatoes Travel to Europe

Frederick the Great encouraging peasants to grow more potatoes

Vincent van Gogh painting: “The potato eaters” (Belgium)

Potato BlightHealthy leaf

Potato BlightHealthy leaf

Blighted leaf

Potato Blight: Phytophthora infestans (fungus)

Potato BlightHealthy leaf

Blighted leaf

Potatoes damaged by blight

Potato Blight: Phytophthora infestans (fungus)

The Irish Potato Blight

Ireland – potato became staple crop in 1800s

The Irish Potato Blight

Ireland – potato became staple crop in 1800s

functionally monoculture – political & cultural considerations

1840s – potato blight hit: population 8 million 6 million

The Irish Potato Blight

Ireland – potato became staple crop in 1800s

functionally monoculture – political & cultural considerations

1840s – potato blight hit: population 8 million 6 million

- 1 million people died; 1.5 million people immigrated to Australia & U.S.A.

Potato Culture – Increasing Mechanization

1870 1970

Holland Potato Farms 100 years apart

Improving Potato Yields

Despite appearances, not yet a priority for the Green Revolution

Tropical Starchy Staples

True Yam Dioscorea sp. Africa, Asia, South America

Taro Colocasia esculenta Asia tropical Pacific

Yautia Xanthosoma sp. South America

Arrowroot Maranta sp. West Indies/South America

Manioc Manihot esculenta South America

Sweet Potato Ipomoea batatas South America

Tropical Starchy Staples

True Yam Dioscorea sp. Africa, Asia, South America

Taro Colocasia esculenta Asia tropical Pacific

Yautia Xanthosoma sp. South America

Arrowroot Maranta sp. West Indies/South America

Manioc Manihot esculenta South America

Sweet Potato Ipomoea batatas South America

Tubers

Tropical Starchy Staples

True Yam Dioscorea sp. Africa, Asia, South America

Taro Colocasia esculenta Asia tropical Pacific

Yautia Xanthosoma sp. South America

Arrowroot Maranta sp. West Indies/South America

Manioc Manihot esculenta South America

Sweet Potato Ipomoea batatas South America

Tubers

Roots

Yams – Another Tuber

Dioscorea sp.

Monocot vines – different species domesticated independently in various tropical areas

Taro – Food from a Corm

Taro – Food from a Corm

Taro – Food from a Corm

Starchy Root Crops – Manioc (Cassava)

Cassava – Food for the “Poorest of the Poor”

Staple food for >500 million people

Cassava – Food for the “Poorest of the Poor”

Staple food for >500 million people

Cassava – Food for the “Poorest of the Poor”

Staple food for >500 million people

Most calories per unit area of land (except for sugar cane)

Cassava – Food for the “Poorest of the Poor”

Staple food for >500 million people

Most calories per unit area of land (except for sugar cane)

Grows in poor soils

Cassava – Food for the “Poorest of the Poor”

Staple food for >500 million people

Most calories per unit area of land (except for sugar cane)

Grows in poor soils

Primarily carbohydrate – low in protein, minerals, vitamins

Cassava – Food for the “Poorest of the Poor”

Staple food for >500 million people

Most calories per unit area of land (except for sugar cane)

Grows in poor soils

Primarily carbohydrate – low in protein, minerals, vitamins

Cyanogenic glycosides must be removed before consumption

Cassava – Food for the “Poorest of the Poor”

Staple food for >500 million people

Most calories per unit area of land (except for sugar cane)

Grows in poor soils

Primarily carbohydrate – low in protein, minerals, vitamins

Cyanogenic glycosides must be removed before consumption

Deteriorates rapidly after harvest (worthless after 48 hours)

Cassava – Food for the “Poorest of the Poor”

Staple food for >500 million people

Most calories per unit area of land (except for sugar cane)

Grows in poor soils

Primarily carbohydrate – low in protein, minerals, vitamins

Cyanogenic glycosides must be removed before consumption

Deteriorates rapidly after harvest (worthless after 48 hours)

Low tech crop no profit for large companies

Starchy Root Crops – Sweet Potato

Ipomoea batatas – Convolvulaceae (Morning Glory Family)

Tuesday Lecture – Stem and Root Crops

Reading: Textbook, Chapter 7