august 2008 plant life cycles chapter #2 modified by georgia agriculture education curriculum office...
TRANSCRIPT
August 2008
Plant Life Cycles
Chapter #2
Modified by Georgia Agriculture Education Curriculum Office
June 2002
August 2008
What is a Life Cycle?
• from the time a seed is planted until the time that a seed is produced
August 2008
What are the Life Cycles?
• Annuals, Biennials, & Perennials
August 2008
Annual
• complete life cycle in one growing season– can be summer
annuals (spring wheat, barley) or winter annuals
(winter wheat)
August 2008
Biennials
• require two growing seasons to produce seed– first season plant
produces vegetation, second season seed (sugar beet, carrot)
August 2008
Perennials
• indefinite growth, can produce seed annually (grasses, trees, shrubs, onion)
August 2008
What is a Seed?
• package containing an embryo (miniature plant) and food
• seeds are alive, need air
August 2008
What is Germination?
• process where embryo changes to seedling (growing plant)
August 2008
What conditions are necessary for germination?
1) moisture
2) correct temperature
3) air
4) some seeds need light
5) some seeds need help (break seed coat [sunflower], remove a chemical from seed, heat, chill [winter wheat])
August 2008
What are Warm Season Crops?
• soil temperature must be 70 degrees F or more for germination (corn, rice, cotton, melons)
August 2008
What are Cool Season Crops?
• soil temp below 70 degrees F (wheat, barley, beets)
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How deep do seeds need to be planted?
• the size of the seed determines
• larger seed = deeper
• corn = 4"
• bluegrass = 1/4"
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Germination Process
1) seed absorbs water, swells
2) water activates enzymes which help digest stored food
3) root grows
4) shoot emerges (is now a seedling)
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What is vegetative growth?
• plant produces food for itself
• extra food is stored in roots,
stems, etc.
August 2008
What is…?
• when new stems are formed in grass plants
Tillering (Stooling)?Tillering (Stooling)?
Jointing?Jointing?• stems of grass plants elongate rapidly
Respiration?Respiration?• process how plants get energy from its
stored food
August 2008
How is food stored in plants?
• form of carbohydrates (sugars)
August 2008
How does respiration work?
Food + Oxygen --> Carbon Dioxide + Water + Energy
August 2008
What factors can influence the rate of respiration?
1) high temps = high rate of respiration
2) high amounts of light = high rate
3) high amounts of water = high rate
August 2008
What is Photosynthesis?
• process of converting water and carbon dioxide into food (sugar) and oxygen in the presence of chlorophyll and light
• photosynthesis and respiration are opposite cycles
August 2008
What is Transpiration?
• process of returning water to the air (in the form of gas)
• 99% of water taken in by roots is transpired
• Wilt = plant transpires more than it takes in
August 2008
What are Nutrients?
• elements needed by plants to grow
What are Macronutrients?
• needed in large amounts
• C, H, O, N, P, K, Ca, Mg, S)
• plants get C, H, O from air and water
August 2008
What are Primary Nutrients?
• N, P, K
What are Secondary Nutrients?
• Ca, Mg, S
• needed less
Nutrients
August 2008
What are Micronutrients?
• needed in small amounts, but essential
• excess amounts are toxic
• Fe, Bo, Mn, Zn, Mo, Cu, Cl
August 2008
16 Essential Nutrients
• C H O P K N S Ca Fe Mg B Mn Cu Zn Cl Mo
• An easy way to help remember essential nutrients is with the help of this sentence (each word or letter stands for each nutrient): C Hopkins Café Managed By Mine Cousin Clomo