1. Unit 5: Plant Science Introduction to Agriscience

2. Plant Science defined
The application of scientific principles to the growth and management of plants.
Agronomy – crops
Forestry – trees
Horticulture – ornamentals and fruits
Floriculture – flowers
Turf – grasses

3. Parts of a Plant

4. The Four Basic Parts of Plants
Leaves
Stems
Roots
Flowers

5. Leaves Function Useful for identification of the plant
Manufactures food for the plant by using light energy. (photosynthesis)
Serves as site of respiration and transpiration.
Useful for identification of the plant
Margin (leaf edge)
Shape
Arrangement

6. Leaves

7. Stems Function Two types of above ground stems
Supports other plant parts such as….
Leaves
Flowers
Fruit
Transports water and nutrients
Two types of above ground stems
Woody – hard with bark covering
Herbaceous – soft with no bark

8. Stems continued Node Internode
Point on a stem where leaves, flowers, roots, or branches originate from.
Contains bud
Internode
Section of a stem between nodes

9. Root Systems Function Types of roots Anchor the plant
Take in water & nutrients
Hold soil
Store food
Types of roots
Fibrous
Tap
Adventitious

10. Fibrous Roots Primary root with many secondary branches
Shallow roots ideal for water absorption (larger area)
Most effective in controlling erosion
Cause more damage to structures/utilities

11. Tap Roots Continuation of primary root Ideal for anchorage
Penetration is greater for water intake
Can be used to store food

12. Adventitious Roots Do not originate from the primary root
Form on stems, branches, leaves, or old woody roots
Include aerial and stilt roots
Can form the largest part of the root system of some plants

13. Roots

14. Flowers Function Contain the sexual organs for the plant.
Produce seeds & fruit.
Attract insects with smell/color for pollination

15. Parts of the Flower Sepals Outer covering of the flower bud.
Protects the stamens and pistils when flower is in bud stage.
Collectively known as the calyx.

16. Parts of the Flower Petals Brightly colored Protects stamen & pistils.
Attracts pollinating insects. (color)
Collectively called the corolla.

17. Parts of the Flower (Stamen)
Male reproductive part
Anther
Manufactures pollen.
Filament
Supports the anther.
Pollen
Male sexual reproductive cell.

18. Parts of the Flower (Pistil)
Female reproductive part
Ovary
Enlarged portion at base of pistil.
Produces ovules which develop into seeds.
Stigma
Usually “sticky”
Receives the pollen.

19. Parts of the Flower (Pistil)
Style
Connects the stigma with the ovary.
Supports the stigma so that it can be pollinated.
Pollen tube grows through toward ovary

20. Nectaries
Responsible for producing nectar which is composed mainly of sugars
Internal – at the base of the pistil
Insects/animals brush against reproductive parts for pollination
External – on leaf stem, midrib, or margin
Attracts predatory insects/animals

21. Parts of the Flower

22. Imperfect Flower Male or female reproductive organs, but not both.
Example:
A male flower has sepals, petals, and stamen, but no pistils.
A female flower has sepals, petals, and pistils, but no stamen.

23. Perfect Flowers
Contains both male and female reproductive structures.

24. Incomplete Flowers Missing one of the four major parts of the flower.
Stamen
Pistil
Sepal
Petal

25. Complete Flowers
Contains male and female reproductive organs along with petals and sepals.

26. Flowers Imperfect flowers are always incomplete but……..
Perfect flowers are not always complete and……..
Complete flowers are always perfect.

27. Groups of flowering plants
Monocot
Single cotyledon
Flower parts in multiples of threes
Leaf veins parallel
Fibrous roots
Vascular bundles scattered

28. Groups of flowering plants
Dicot
Two cotyledons
Flower parts in multiples of four or five
Leaf veins branching
Tap roots
Vascular bundles in a ring

29. Monocot vs. Dicot

30. Pollination vs. Fertilization
Pollination – the transfer of pollen from the anther to the stigma (allows fertilization to take place)
Self pollination – when the pollen comes from the same flower or plant
Cross pollination – when the pollen comes from a different plant
Fertilization – union of the nuclei of the pollen and the nuclei of the ovule (produces seeds)

31. Parts of a Seed Seed Coat Protects the seed.
Sometimes very hard & difficult to germinate.
Horticulturists assist germination by scarifying the seed coat or damaging the seed coat to promote germination.
Stratifying seeds mimics the freeze/thaw cycle of nature.

33. Parts of a Seed Endosperm Embryo
Supplies food for the germinating seed.
Embryo
The young plant.

34. Propagation

35. Propagation What is Propagation? Two Types of Propagation
Increasing the number of a plant species or reproduction of a species.
Two Types of Propagation
Sexual
Asexual

36. Sexual Propagation The use of seed for reproducing plants.
Allows the most variation of any propagation method.
Only way to obtain new varieties and increase hybrid vigor of the plants.
Less expensive & quicker than other methods.
Occurs through pollination.

37. Asexual Propagation
Use of a part of a plant for reproducing new plants, other than the seed. (leaf, stem, root, tissue culture)
Also called vegetative propagation.
The new plant is an exact duplication of the parent plant. (same DNA)

38. Methods of Asexual Propagation
Cuttings
Vegetative parts that the parent uses to regenerate itself.
Examples:
Leaf cuttings.
Root cuttings.
Stem cuttings.
Root hormones are applied to speed up root development.

39. Methods of Asexual Propagation
Layering
The stem is encouraged to root while still attached to the parent plant.
Examples:
Simple layering.
Tip layering.
Air layering.

40. Methods of Asexual Propagation
Division
Dividing or separating the main part of the plant into smaller parts.
Grafting
Joining two plants together so they grow as one.
T-Budding is the most common method.

41. Methods of Asexual Propagation
Tissue Culture
Also called micropropagation.
The use of a very small and actively growing part of the plant to produce a high number of new plants.
Cloning achieved by tissue culture.

42. Plant Life Cycles Annuals – complete life cycle in one season
Warm season – spring and summer
Cool season – fall and winter
Biennial – complete life cycle in two years
Vegetation produced the first year and fruit produced the second year

43. Plant Life Cycles Perennial – live year after year
Herbaceous – usually die back in winter and grow new vegetation each year
Woody – do not die back because they withstand the colder temperatures

44. Photosynthesis

45. Photosynthesis
Process in which light energy is converted to chemical energy in the form of a simple sugar (glucose).
Chlorophyll & chloroplast are essential.
Carbon dioxide is used to manufacture food for plant and releases oxygen necessary for animal life at the same time.

46. Photosynthesis reaction

47. Photosynthesis
Rate of photosynthesis (food making) process depends on & varies with the….
Light intensity
Temperature
Concentration of carbon dioxide in the atmosphere.

48. Carbon Dioxide
Shortage of carbon dioxide causes a low rate of photosynthesis.
Enclosed greenhouses can have a shortage of carbon dioxide.
A CO2 generator might be used to correct a shortage of carbon dioxide in the greenhouse.

49. Light Low light hinders plant growth.
A dark room reduces the photosynthetic rate and plants will have stunted growth and yellow leaves.
All plants have a preferred range, but they can adapt to various levels of light brightness (intensity).

50. Temperature Affects the process of photosynthesis.
Best rate of photosynthesis occurs between degrees Fahrenheit.
Extremes of temperature can completely stop the process.

51. Respiration

52. Respiration
The process through which energy stored in organic molecules is released to do metabolic work
Conducted in all living cells, it is controlled by enzymes, and releases carbon dioxide and water

53. Respiration reaction

54. Respiration Plants “breathe” through their leaves.
The underside of the leaves have microscopic pores called stomata.
Air passes in and out of the leaf through the stomata.
Respiration takes place 24 hours a day.
Each cell and the plant as a whole take in oxygen and gives off carbon dioxide.

55. Transpiration Process in which excess water is given off by plants.
Water escapes through stomata.
Rate depends on light, temperature, humidity, wind, and water supply.

56. Competition
Process in which two organisms are trying to use the same resource.
Water
Space
Sunlight
Nutrients

57. Competition
Intraspecific – competition between organisms of the same species
Interspecific – competition between organisms of different species

58. Plant Nutrition

59. Nutrients
There are 16 chemical elements essential for plant growth and production.
Divided into non-mineral and mineral classes and into macronutrient and micronutrient classes

60. Nutrients Non-mineral – provided by air and water
Mineral – provided by soil and fertilization
Macronutrients – needed in large quantities for plant growth and production.
Micronutrients – needed in small quantities for certain reactions within the plant such as hormone and chlorophyll production.

61. Macronutrients (Air/Water)
Carbon – C
Hydrogen – H
Oxygen - O

62. Macronutrients (Soil)
Nitrogen – N (major)
Phosphorus – P (major)
Potassium – K (major)
Calcium – Ca (lime)
Magnesium – Mg (lime)
Sulfur - S

63. Micronutrients Boron - B Copper - Cu Chloride - Cl Iron - Fe Zinc - Zn
Manganese - Mn
Molybdenum - Mo

65. Fertilizers

66. Fertilizers Complete fertilizer must contain the three nutrients.
Nitrogen
Phosphorus
Potassium

67. Fertilizers Come in various forms….
But most nutrients within a fertilizer must become in liquid form (soluble) to be used by plants.

68. Organic Fertilizers
Include animal manures & compost made with plant or animal products.
Examples:
Dried & pulverized manures.
Bone Meal (4-12-0)
Phosphorus is the primary element
Soybean Meal (7-2-1)
Blood Meal (12-0-0)

69. Fertilizers Organic Fertilizers Inorganic Fertilizers
Usually slow acting and long lasting forms of nitrogen but lacking in the other primary nutrients.
Except bone meal.
Inorganic Fertilizers
Have a higher analysis of soluble nutrients that have been blended together for a specific purpose.

70. Fertilizer Application
Broadcasting or spreading evenly over the entire surface is used on turf and home lawns.
Side-dressing is done by placing fertilizer in bands about 8 inches from the row of growing plants.
Foliar application is the spraying of fertilizer onto the leaves of plants.

71. pH of Growing Media
pH has the most impact on the availability of nutrients in the soil/media.
pH Scale
Ranges from 0 to 14.
Indicates the level of acidity or alkalinity.
7 is considered neutral.
Everything greater than 7 is considered alkaline (basic).
Everything less than 7 is considered acidic.

72. pH Scale

73. pH Scale

74. Amending the pH
Alkaline soils can be made more acidic by lowering the pH value with sulfur or aluminum sulfate.
Acidic soils can be made more alkaline by raising the value with lime.
Lime usually applied as finely ground dolomitic limestone that supplies both calcium and magnesium.

75. Other factors that affect plant growth and production
Competition – when two plants are striving to get nutrients, water, sunlight, or space from one another.
Insects – damage plants and fruit
Climatic catastrophes – temperature, hurricanes, tornadoes, drought, flood, freeze
Diseases – damage plants and fruit

76. Growing Media

77. Types of Growing Media Soil Top layer of the Earth’s surface.
Primary medium for cultivated plants.

78. Types of Growing Media Sphagnum Moss
Used for encouraging root growth under certain conditions. Holds water well, but drains.

79. Types of Growing Media Perlite
Volcanic ash used for water adhesion and aeration in media mixes.

80. Types of Growing Media Vermiculite
A mineral; mica-type material used for water holding in media mixes.

81. Types of Growing Media Peat Moss
Used in media mixes of various types for water holding capacity and drainage.

82. Types of Growing Media Bark
Used in media mixes of various types for water retention, drainage, and aeration.

83. Types of Growing Media Compost
Decomposed organic matter, contains most nutrients needed by plants.

84. Careers

85. Floriculture Careers
Related to flower production and use.

86. Floriculture Careers Floral designer Flower grower Greenhouse manager
Designs flowers for a florist or business.
Flower grower
Produces flowers used in floral design.
Greenhouse manager
Manages the production process for a flower grower.

87. Floriculture Careers Retail florist Wholesale florist
Floral business that furnishes flowers to the general public.
Wholesale florist
Floral business that furnishes flowers and supplies to a retail florist.

88. Nursery/Landscape Careers
Related to the use & production of plants for aesthetic purposes.
Plants may be used around homes, businesses, parks, etc.

89. Nursery/Landscape Careers
Greenskeeper
Takes care of golf course turf.
Landscaper
Installs plants in various locations.
Landscape architect
Design plans for plant installation.

90. Nursery/Landscape Careers
Nursery operator
Grows trees and shrubs needed for landscaping.
Turf farmer
Grows turfgrass for sale.

91. FFA Advisor
High School