Legumes are members of pea, bean family (Fabaceae) and are very important sources of food due to their highly nutritious seeds Legume seeds are very high in protein due to the nitrogen fixing root nodules with which legumes can extract N 2 gas to make ammonium which they use when synthesizing protein
Top agricultural products, by crop types (million metric tons) 2004 data Cereals2,263 Vegetables and Melons866 Roots and Tubers715 Milk619 Fruit503 Meat259 Oilcrops133 Fish (2001 estimate)130 Eggs63 Pulses60 Vegetable Fiber30 Source: Food and Agriculture Organization (FAO) [ Food and Agriculture Organization
Top agricultural products, by individual crops (million metric tons) 2004 data Sugar Cane1,324 Maize721 Wheat627 Rice605 Potatoes328 Sugar Beet249 Soybeans204 Oil Palm Fruit162 Barley154 Tomato120 Source: Food and Agriculture Organization (FAO) Food and Agriculture Organization
Plant Storage Organs Some examples of storage organs in plants: (a) tap root of carrot (Daucus carota); (b) bulb of onion (Allium sp.); (c) corm of crocus (Crocus sp.); (d) rhizome of iris (Iris sp.); (e) root tuber of dahlia (Dahlia sp.); (f) stem tuber of potato (Solanum tuberosum).
Plant Storage Organs Rhizomes – are horizontal stems that are underground – reduced scale-like leaves are present on the surface of the rhizome and adventitious roots form on its underside – buds found at the nodes can give rise to new plants – ginger and iris Tubers – are enlarged storage tips of a rhizome – the white potato is a tuber – the eyes of a potato are actually buds located at its nodes and each bud can give rise to a new plant Bulbs and Corms are modified stems found in monocots – Bulbs are erect underground stems with both fleshy and papery leaves; food is stored in the fleshy leaves – Onions, tulips, daffodils, hyacinths, and lilies all have bulbs
Plant Storage Organs Corms store food reserves in the stem, not the leaves – they are erect underground stems are covered only with dry papery leaves – corms can multiply by producing small corms – plants with corms are gladiolus, crocus and taro Tuberous roots are modified fibrous roots that have become fleshy and enlarged with food reserves – they can also function in asexual reproduction – tuberous begonias, dahlias and sweet potatoes Taproots may also function as food storage organs – especially for biennial plants like carrots, rutabaga and turnips
New Foods to Europe Alfred Crosby has gathered data which suggests the introduction of maize and potatoes alone allowed the doubling of Europe’s population in the period after Columbus’ discovery of America Corn was important because of the very high yields possible from corn agriculture
New Foods to Europe Potatoes were important because, unlike corn, they provided a complete set of amino acids (corn lacks lysine) - potatoes were great for poor people in Europe because they can be easily grown in areas of poor, depleted soil, they will grow well during a short growing season (typical of northern Europe) and they can even be left in the ground if necessary, so they are less sensitive to the timing of the harvest than competing poor-soil crops, such as rye, which must be harvested when the seeds are ripe or it will rot
The Potato Comes to Europe The potato came to Europe about 1565 - at first, most people in Europe, including the Irish, used the potato as a back up for grain production, but by the end of the 17th century, it had become an important winter food; by the mid-eighteenth century it was a general field crop and provided the staple diet of small farmers during most of the year
Lessons learned? “Whatever may be the misfortunes of Ireland, the potato is not implicated. It, on the contrary, has more than done its duty, in giving them bones and sinew cheap... There is no other crop equal to the potato in the power of sustaining life and health.” - Bain 1848
Origin of Sweet Potato Sweet Potato – Ipomoea batatas – was first domesticated in Peru about 5 or 6 thousand years ago – its culture spread through out South and Central America and the Caribbean region The Arawak People called it batata which became corrupted into the word potato It was brought to Europe by Columbus around 1500
Sweet Potato Sweet potato is a tuberous root cultivated by vegetative propagation (cuttings) It was a staple food throughout the Americas and also across the Polynesian islands – big question is how did it get to Polynesia – by people or by accident?
Plans for a balsa wood raft – used along coast of South America -drawn by F.E. Paris in 1841
Thor Heyerdahl’s balsa wood raft – 1947 in action and model
Possible Inca route to Pacific Islands and Kon-Tiki route
Polynesians to South America? It is more likely that Polynesians crossed the Pacific and obtained sweet potatoes directly from the South Americans In most parts of the South Pacific, sweet potatoes are called kumara, very similar to the Peruvian word of cumara However, in Hawaii, the sweet potato is called ‘uala, more similar to the Columbian word kuala - perhaps a couple of groups were in contact with South America
Sweet Potato Agriculture Sweet Potato is rich in carbohydrates, vitamins and minerals – some of the carbohydrates are in the form of sugars rather than starch, hence the sweet taste About 50% more calories than white potato, but slightly less protein Two main varieties – a drier, starchier yellow- fleshed variety and a moister, sweeter, deeper orange variety China dominates sweet potato cultivation, but also important in Japan and several African countries; increasing production in US
Cassava Cassava (Manihot esculenta), also called yucca or manioc, is a woody shrub of the Euphorbiaceae family It is cultivated as an annual crop in many parts of the tropical world because it has a starchy tuberous root that is a major source of carbohydrates
Cassava The cassava root is long and tapered, with a firm homogeneous flesh encased in a detachable rind, about 1 mm thick, rough and brown on the outside. Cassava roots are very rich in starch, and contain significant amounts of calcium (50 mg/100g), phosphorus (40 mg/100g) and vitamin C (25 mg/100g). However, they are poor in protein and other nutrients.
Cassava Agriculture Wild populations of M. esculenta subspecies flabellifolia, shown to be the progenitor of domesticated cassava, are centered in west-central Brazil where it was likely first domesticated no more than 10,000 years ago With its high food potential, it had become a staple food of the native populations of northern South America, southern Mesoamerica, and the Caribbean by the time of the Spanish conquest, and its cultivation was continued by the colonial Portuguese and Spanish. Forms of the modern domesticated species can be found growing in the wild in the south of Brazil. There are several wild Manihot species
Cassava Consumption Cassava is classified as "sweet" or "bitter" depending on the level of cyanogenic compounds; improper preparation of bitter cassava causes a disease called konzo. Cassava can be cooked in various ways. The soft-boiled root has a delicate flavor and can replace boiled potatoes in many uses: as an accompaniment for meat dishes, or made into soups, purees, stews, etc. Deep fried (after boiling or steaming), it can replace fried potatoes, with a distinctive flavor. Tapioca and foufou are made from the starchy cassava root flour.
Taro is believed to have originated in Southeast Asia and spread west and east thousands of years ago – may have been cultivated very early by people in SE Asia – eventually reached tropical Africa and from there was brought to the West Indies and South America by slaves – today it is cultivated in the tropics where it thrives in wet, saturated soil conditions – propagated by planting corms
Taro cultivation The corm is steamed, crushed and made into a dough, then allowed to ferment by microbes – the paste is then eaten with the fingers or rolled into small balls – this is the method for making poi – staple Hawaiian food Corms can also be prepared like potatoes – steamed, baked, roasted, or boiled Corm is about 25% carbohydrate (about 3% sugar), 2% protein and very little fat Good source of calcium due to presence of calcium oxalate crystals – will cause intense burning if eaten raw so must be cooked to break down the crystals