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Plant Science Agriscience Applications. By: Johnny M. Jessup, FFA Advisor/Agriculture teacher. Parts of a Plant. The Four Basic Parts of Plants. Leaves Stems Roots Flowers. Leaves. Function Manufactures food for the plant by using light energy.
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Plant ScienceAgriscience Applications By: Johnny M. Jessup, FFA Advisor/Agriculture teacher
The Four Basic Parts of Plants • Leaves • Stems • Roots • Flowers
Leaves • Function • Manufactures food for the plant by using light energy. • Useful for identification of the plant • Margin (leaf edge) • Shape • Arrangement
Stems • Function • Supports other plant parts such as…. • Leaves • Flowers • Fruit • Two types of above ground stems • Woody • Herbaceous
Root Systems • Function • Anchor the plant • Take in water & nutrients • Two types of root systems • Fibrous • Tap Root
Flowers • Function • Contain the sexual organs for the plant. • Produce seeds & fruit.
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.
Parts of the Flower • Petals • Brightly colored • Protects stamen & pistils. • Attracts pollinating insects. • Collectively called the corolla.
Parts of the Flower (Stamen) • Male reproductive part • Anther • Manufactures pollen. • Filament • Supports the anther. • Pollen • Male sexual reproductive cell.
Parts of the Flower (Pistil) • Female reproductive part • Ovary • Enlarged portion at base of pistil. • Produces ovules which develop into seeds. • Stigma • Receives the pollen.
Parts of the Flower (Pistil) • Style • Connects the stigma with the ovary. • Supports the stigma so that it can be pollinated.
Imperfect Flower • Male or female reproductive organs not, 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.
Perfect Flowers • Contains both male and female reproductive structures.
Incomplete Flowers • Missing one of the four major parts of the flower. • Stamen • Pistil • Sepal • Petal
Complete Flowers • Contains male and female reproductive organs along with petals and sepals.
Flowers • Imperfect flowers are always incomplete but…….. • Perfect flowers are not always complete and…….. • Complete flowers are always perfect.
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.
Parts of a Seed • Endosperm • Supplies food for the germinating seed. • Embryo • The young plant.
Propagation • What is Propagation? • Increasing the number of a plant species or reproduction of a species. • Two Types of Propagation • Sexual • Asexual
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.
Asexual Propagation • Use of a part of a plant for reproducing plants. • Also called vegetative propagation. • The new plant is an exact duplication of the parent plant.
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.
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.
Methods of Asexual Propagation • Division • Dividing or separating the main part of the plant into smaller parts. • Grafting • Joining two plants together as they grow as one. • T-Budding is the most common method.
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.
Photosynthesis • Series of processes in which light energy is connected to chemical energy in the form of a simple sugar. • Chlorophyll & chloroplast are essential. • Carbon dioxide is used to manufacture food for plant and releases oxygen necessary for animal life at the same time.
Photosynthesis • Rate of photosynthesis (food making) process occurs depends on & varies with the…. • Light intensity • Temperature • Concentration of carbon dioxide in the atmosphere.
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.
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).
Temperature • Affects the process of photosynthesis. • Best rate of photosynthesis occurs between 65-85 degrees Fahrenheit. • Extremes of temperature of temperature can completely stop the process.
Types of Growing Media • Soil • Top layer of the Earth’s surface. • Primary medium for cultivated plants.
Types of Growing Media • Sphagnum Moss • Used for encouraging root growth under certain conditions.
Types of Growing Media • Perlite • Volcanic glass material used for starting new plants and in media mixes.
Types of Growing Media • Vermiculite • A mineral; mica-type material used for starting plant seeds and cuttings and in media mixes.
Types of Growing Media • Peat Moss • Used in media mixes of various types.
pH of Growing Media • pH has the most impact on the availability of nutrients in the soil/media. • pH Scale • Ranges from 0 to 15. • 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.
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.
Fertilizers • Complete fertilizer must contain the three nutrients. • Nitrogen • Phosphorus • Potassium
Fertilizers • Come in various forms…. • But most nutrients within a fertilizer must become in liquid form (soluble) to be used by plants.
Organic Fertilizers • Include animal manures & compost made with plant or animal products. • Examples: • Dried & pulverized manures. • Bone Meal • Phosphorus is the primary element • Soybean Meal
Fertilizers • Organic 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.
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.