Welcome to an overview of what Economic Botany has to offer.
It will be a distance learning course this spring 2000, so below are highlights of what I plan
to be doing in the TopClass format
LECTURE 3 HIGHLIGHTS FOR BIOLOGY 03074, ECONOMIC BOTANY: CROPS; CEREAL GRAINS
Text: 2nd ed.: Ch. 12 (pp. 188-205), Ch. 15 (aspects), Ch. 22 (pp. 386-392); 1st ed.: Ch. 12 (pp. 175-191), Ch. 15 (aspects), Ch. 22 (pp. 354-357)
possible web site: http://www.brynmawr.edu/Acads/Geo/SenSem/1997/Zaradic1/greenout.html
(Green Revolution issues in outline form with annotated bibliography)
Poaceae (Graminae): the grass family. 600 genera, 10,000 species. The flower (floret) is highly specialized and with its own terminology. The flower and bract unit is the spikelet.. Fruit a caryopsis (grain). Leaves alternate, with blades, ligules, and sheaths. Stems (culms) round, with hollow internodes, and roots fibrous, e.g., Oryza, rice; Bambusa, bamboo; Cynodon, bermuda grass; Zea, maize (corn); Triticum, wheat.
MAIZE/CORN: ZEA MAYS
morphology: Corn is an unusual cereal with separate tassel-male, ear-female inflorescences, respectively. Husks (shucks)-specialized bracts around the ears. Silks-stigmas and styles of individual flowers.
origins: Central and South America, about 4000 BC
growing conditions: Corn is grown under many different conditions, preferably warm with rainfall. Corn rapidly depletes the soil of nutrients.
agronomic issues: Corn varieties are dependent on the amount and type of starch, e.g.,
Popcorn: hard starch around soft starch, which explodes and turns inside out with heat.
Dent corn: most widely grown corn in the Corn Belt, for animal feed, corn starch, corn meal.
Sweet corn: more sugar than starch in endosperm cells, hence popular for human tables.
history: Maize is the basic foodstuff of Native Americans. Corn's increased use and productivity in this century based on discovery of hybrid corn. 1970 southern corn leaf blight epidemic, over $4 billion in losses
WHEAT: TRITICUM AESTIVUM
morphology: The spikes are tightly packed with awned grains
origins: Wheat arose from Near East (Fertile Crescent), with indications of domestication by 7000 BC. Modern bread wheat is a hexaploid (6N=42), so that following the chromosome character and number gives clues to its origin. growing conditions: Prefers temperate grasslands and relatively cool temperatures.
agronomic issues: Most widely cultivated crop in the world. T. aestivum, bread wheat, has been selected for lots of protein in endosperm, including gluten (the proteins that allow bread dough to be elastichistory: Wheat historically important--think of ancient wars always beginning after harvest time. More modern concern was how to grow mass quantities of wheat in areas like USA Midwest. Wheat rust: Puccinia graminis, named for spore color. Billions of dollars worldwide yearly lost to cereal rusts. Rusts weaken plants and lower yield.
morphology: Rice is a multi-stemmed annual, height to 1 m or more.
origins: Has been cultivated for at least 7000 years in Asia, possibly with many sites of origin.
agronomic issues: 2+ billion people depend on it for food. Rice can be grown dry (upland rice), but mostly in paddies (lowland rice).
THE"GREEN REVOLUTION"
In 1941, set up of field research in Latin America with WWII concerns looming. At CIMMYT in Mexico City, in 1950s, Norman Borlaug worked on high-yield dwarf cultivars of wheat, winning 1970 Nobel Peace Prize for"Green Revolution." These are high impact crops that demand a lot of fertilizer, pesticide, water, and are best suited for mechanical farming.
|main page| |background| |03028: Physiology| |03048: Anatomy|
|03050: Invertebrate Zoology| |03051: Vertebrate Zoology| |03074: Economic Botany|
Please send comments and questions to: cronewil@hvcc.edu
Copyright 1999 by Wilson Crone
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This page updated on October 4, 1999