Date post: | 19-Jan-2016 |
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IMPORTANCE OF PLANTS
Importance of Plants
• Oxygen• Food/feed• Medicine– http://www.youtube.com/watch?v=6iEOTB1UjjQ
• Absorb Carbon Dioxide• Decoration (Aesthetic)
PLANT LIFE CYCLES
Plant Life Cycle• Annual– Goes from seed to producing seed in one growing season– Ex. Corn, beans
Summer Annuals
• Summer annuals germinate in the spring. Summer annuals produce leaves, flowers, and seed before dying during the summer or fall. – Many crops and garden plants are annuals.
– Corn, soybeans, rice, wheat, potatoes, and tomatoes
– Petunias, impatiens, marigolds, and zinnias
– Ragweed, pigweed, lambsquarter, crabgrass
Photo, courtesy USDA Peggy Greb
Winter Annuals
• The seed of a winter annual germinates in the fall. The immature plant overwinters as a compact rosette. Once the plant has received a sufficient period of cold treatment, it bolts.
Winter Annuals
• Bolting is a process in which the stem of a plant rapidly elongates at the time of flowering. – Flowers then develop, seeds are set, and the plant
dies. – Winter wheat
Plant Life Cycle• Biennial– Goes from seed to producing seed in two growing seasons– 1st year – vegetative growth– 2nd year – vegetative and flower growth– Ex. Carrot, burdock
Biennials
• Biennials are plants that normally require two growing seasons to produce flowers and seed before dying. – First growing season: biennials grow vegetatively.
– Next: plants go dormant and rest until the Spring
– Winter: receive a required cold treatment
– Growth is resumed in the spring of the 2nd season.
– The plants bolt, flower, produce seed, and die.
– Hollyhock, Sweet William, parsley, beets, and carrots
Plant Life Cycle• Perennial– Lives more than two growing seasons– Ex. Trees, shrubs
Perennials
• A perennial is a plant that has a life cycle of more than two growing seasons. – May take perennial plants a few years to many years
to reach reproductive maturity. – Perennials may be woody like trees
and shrubs or herbaceous.
On the flip chart(s) – create a Venn-Diagram to compare and
contrast the three types of plant life cycles
MAJOR PLANT STRUCTURES
Major Plant Structures
• Flower– Attracts insects for
pollination
• Fruit– Seed-carrying structure
Major Plant Structures
• Seeds– Produces new plants
• Leaves– Produces food/sugars
Major Plant Structures
• Stem– Supports the plant– Transports water,
nutrients and food/sugar
• Roots– Anchors plant– Absorbs water and
nutrients– Stores food