The Role of Cultivated Plants in
the Living World
Crop Science 1
Fall 2004
Who are Plant Scientists?
• The first plant scientists were those who:
– Observed how plants grew
– Developed ideas about the process and how to
improve it
– Tested those ideas
– Came to conclusions
What if there were no Plants?
• Without animals plants would survive
and/or flourish
• Without plants all animals would die
• Without humans most farmed plants would
become extinct
Plants as a Food Source
• Plants – autotrophic use sun energy to
create food
• Animals – heterotrophic depend upon plants
for their food
• Photosynthesis – Carbon dioxide (air) +
water (roots) = carbohydrates
• Photosynthesis occurs in leaves and other
green parts (chloroplasts)
Cultivation
• Definition: the growing or tending of crops
• Cultivation came into use about 18,000 years ago
(10,000 years after modern humans)
• 18,000 years ago – Egypt - Cereals (Wheat,
Barley)
• 6,000 years ago – Europe – Cereals
• 5,000 years ago – Mexico – Corn
• 3,500 years ago – South America – Potatoes
• 3,500 years ago - Far East - Rice
Feeding the World’s Population
•
•
•
•
•
•
Cereal Crops
Roots and Tubers
Oil Crops
Sugar
Fruit Crops
Vegetable Crops
Cereal Crops
•
•
•
•
•
•
•
•
•
Wheat
Maize (Corn)
Rice
Barley
Oats
Sorghum
Rye
Millet
Over ½ the world’s food
supply comes from these
Roots and Tubers
• Potatoes
• Sweet Potatoes
• Cassavas
Oil Crops
•
•
•
•
•
•
•
•
Soybeans
Corn
Peanuts
Palm
Coconut
Sunflowers
Olive
Safflower
Sugar
• Sugar Cane
• Sugar Beets
Fruit Crops
•
•
•
•
•
Bananas
Oranges
Apples
Pears
Etc.
Vegetable Crops
•
•
•
•
•
Lettuce
Carrots
Broccoli
Asparagus
Etc.
Some Important Food Crops
Ranked According to Calorie
Table 1-1
and Protein Production per
Unit of Land Area
Protein
Calories
Rank
Produced per Produced per
Unit Area
Unit Area
1
Sugar Cane
Soybeans
2
Potato
Potato
3
Sugar Beets
Corn
4
Corn
Peanuts
5
Rice
Sorghum
6
Sorghum
Peas
7
Sweet Potato
Beans
8
Barley
Rice
9
Peanuts
Barley
10
Winter Wheat Winter Wheat
Energy Transformation
• 22 pounds of grain to produce 2.2 pounds of beef
• Bushel of grain = protein requirement for 23
people
– If fed to chickens energy for 2 and protein requirement
for 8 people
• Animals consume grain that is not edible to
humans and produce protein of a higher quality
and provide necessary minerals and vitamins
Past and Present
• 1970’s brink of famine, ecological disaster
• 1980’s reversal of projection
• Reversal was achieved by:
– Agricultural research available to developing countries
– New Cultivars – cultivated varieties (wheat, corn, rice)
• By 2009, food consumption in nearly ½ of the
developing countries will not meet nutritional
standards
Non-Food Benefits
• Wood and wood products
– Building material, fuel, landscape, paper, etc.
• Textiles from fiber-producing crops
– Clothing, rope, twine, burlap and etc.
• Drugs and medicines
– Aspirin from willow trees, codeine from
poppies, tobacco
Non-Food Benefits
• Industrial
– Latex from rubber tree
– Pitch, turpentine and resin from pine trees
• Aesthetic
– Perfumes and spices
• Environmental
– Erosion control
– Oxygen
Challenges for the Future
• New challenges more social than production
• Starvation Exists – social, political reasons
• Increased GMO’s (genetically modified
organisms)
– Round-up Ready, Flavr Savr, Rice w/vitamin A
Lab Assignment
• Divide into Groups of 3-4
• Using the internet research:
–
–
–
–
–
–
–
World Food Supply – 1800-2010
World Population – 1800-2010
U.S. Corn Yield – 1700-2010
Average U.S. Farm Size – 1700-2010
Average World Farm Size – 1700-2010
Top 25 Commodities in U.S. 2000
Pick 3 California Counties – top 10 commodities
• Email clintcowden@westhillscollege.com