REVIEW Flashcards
Taxonomic Hierarchy
• Includes: − Kingdom − Division/Phylum − Class − Order − Family − Genus − Species
Kingdoms
• Are the most general taxon used in classifying organisms • Include: − Monera − Prostita − Fungi − Plantae − Animalia
Divisions
• Have the standard suffix -phyta or -phtina
• Are indicative of distinctive modes of reproduction and morphology of
plants
• Are the broadcast categories in the plant kingdom
• Are used when referring to plants
− typically phylum
Classes
• Have the standard suffix -opsida or -idae
• Are included in divisions
− many classes are in each division
Orders
• Have the standard suffix –ales or –inae
• Are included in classes
− many orders are in each class
Families
• Have the standard suffix -aceae • Share common characteristics seen in: − plant appearances • some families may have great diversity in appearance − seed location and appearance − growth habit • Share many comparable factors such as: − cultural requirements − insect problems − disease problems
Genus
• Is sometimes followed by:
− sp.: indicates a single unidentified species
− spp.: refers to multiple species within a genus
• neither are underlined or italicized
• i.e. Acer sp.
Species
• Is analogous to the first name of the plant
− more specific than genus
• Refers to groupings of plants which consistently produce plants of
the same types
Cells and types
• Are the smallest living unit of an organism
• Are specialized for a specific function
• Are organized into tissue
• Are totipotent within plants
− totipotency is the unique ability of plants cells to divide, grow
and differentiate into new cells which hold the same genetic identity as the mother cell
− parenchyma cells are some of the least specialized and most likely to remain totipotent
11. Cells types
• Include:
− parenchyma cells
− sclerenchyma cells
− collenchyma cells
− xylem tissue cells
− phloem tissue cells
− epidermal cells
Parenchyma Cells
• Are the least specialized plant cells
• Are living at maturity
• Contain thin, flexible cell walls
• Have a large central vacuole
• Have the ability to separate into other cells under special conditions
− occurs after injury to repair and replace organs
Collenchyma Cells
• Contain thicker primary cell walls − have uneven thickness • Are living at maturity • Are found in ground tissue • Are used in support of herbaceous plants − i.e. strings in celery • Provide support in young plants
. Sclerenchyma Cells and types
• Contain thick secondary cell walls which harden to strengthen the plant
• Are dead at functional maturity
• Cannot increase in length
• Are found in ground tissue
Sclerenchyma Cells types
• Include:
− fibers: long, slender cells with a secondary cell wall
• i.e. hemp fibers in rope
− sclereids: shorter cells with an irregular shape
• i.e. stone cells in pears
Xylem Tissue Cells
• Make up the woody walls of plants
• Contain thick secondary cell walls
− deposited unevenly in a coil-like pattern to enable
stretching
• Are dead at functional maturity
• Are found in vascular tissue
• Include parenchyma cells and non-living conductive cells such as:
− tracheids: long, slender cells connected by pits
− vessels: shorter, larger diameter cells with perforated cell wall
ends
• found only in angiosperms
Phloem Tissue Cells
• Are alive at functional maturity
• Are found in vascular tissue
• Include conductive cells such as:
− sieve-tube members: conduit for sucrose transport
− companion cells: contain a nucleus which may control the sieve-tube element and may aid in sucrose loading
Epidermal Cells
• Prevent water loss and provide a barrier against fungi and other
invaders
• Are closely packed, contain little inter-cellular space
• Are found in dermal tissue
• Are located under a waxy cuticle layer which aids in
prevention of water loss
• Include:
− guard cells: cover stomata openings
• regulate exchange of water vapor, oxygen and carbon
dioxide
Cell Membrane
• Surrounds the cell as a thin layer of protein (about eighth-millionths of a
millimeter thick)
• Can be found inside the cell wall
• Allows some substances to pass into the cell while blocking others
• Is also known as the plasma membrane
• Is involved in cellulose production for the assembly of cell walls
• Is composed of highly structured proteins and phospho-lipids
Cell Wall
- Are found only in plants
- surrounds the cell
- Provides structure and support
- Bonds with other cell walls to create plant structure
Chloroplast
- Is an elongated organelle containing chlorophyll
* converts light and carbon dioxide to usable energy
Cytoplasm
• Is a gel-like material outside the nucleus, but inside cell
membrane
• Contains all other organelles floating in cytoplasm
Golgi Apparatus
• Is a flat, layered organelle (dictyosomes) which resembles a stack of
pancakes
• Is located near the nucleus
• Packages proteins and carbohydrates for export from the cell
• Modifies proteins and lipids before distributing them
Mitochondria
- Is the powerhouse of the cell
- Are spherical, rod-shaped organelles
- Have a double membrane
- Converts energy stored in glucose to ATP for the cell (Respiration)
Nucleus
- Controls functions of the cell
- Contains the genetic material (DNA) of the cell
- Is surrounded by the nuclear membrane
Ribosomes
- Are small organelles found in large numbers in the cytoplasm
- Create proteins from amino acids
- Can only be seen with an electron microscope
- Composed of two subunits containing RNA and proteins
Rough Endoplasmic Reticulum
• Is located in the cytoplasm
• Is covered with ribosomes which give it a rough appearance
• Transports materials through the cell, secretes, stores and creates
proteins
Smooth Endoplasmic Reticulum
- Is located in the cytoplasm
- Transports materials through the cell
- Contains enzymes
- Produces and digests lipids and membrane proteins
Vacuole
- Is surrounded by a membrane
- Is filled with fluid
- Takes up most of the cell
- Maintains the shape of the cell
- Is the “cell trash can”
Plant Parts
• Include: − roots − stems − leaves − flowers − fruit − seeds
Roots and Types
- Are usually underground
- Anchor plants in soil
- absorb water and nutrients
- Provide physical support for the stem
- Can store food for plant
• Include: − taproots − lateral roots − adventitious roots − fibrous roots
Taproot
• Characteristics are: − single, dominant roots − grow directly downward − sprout other fibrous roots − can be modified for food and water storage and uptake
Lateral Roots
- Extend horizontally from the taproot
* Extract nutrients and water from the soil
Adventitious Roots
- Form from shoot tissues
- Arise in stems and leaves
- Are used when cloning plants from cuttings
Fibrous Roots
- Are thin, slender roots
- Collect water and nutrients close to the soil surface
- sprout from primary roots
Stems
- support leaves, flowers and fruit
- Transport carbohydrates and nutrients throughout the plant
- Transports water from the roots to the plant (xylem)
Leaves
- Are the major site of food production for the plant (chloroplasts)
- Contain structures which convert sunlight to chemical energy (photosynthesis)
- Create food and energy in the plant through the process of photosynthesis
Leaf Parts
• Include: − midrib • main, central vein of a leaf − petiole • leaf stalk which attaches the leaf to the plant − stem • main support of the plant − stipule • small, leaf-like appendages at the base of the petiole − vein • transports water, minerals and food energy throughout the plant
Leaf Vein Patterns
• Include:
− parallel
• several large veins run alongside each other from the base of the blade to the tip (monocots)
− palmate
• several main veins of about equal size, all of which extend from a common point at the base of the leaf
(dicots)
− pinnate
• one large, central vein, the midrib, with other large
veins branching from the sides
Leaf Edges
- Are also known as leaf margins
- Vary in texture and appearance
- Are a major characteristic in the determination of plant type
Leaf Shape
• Is of major importance in identifying plants
• Includes:
− blade shape: shape of the entire leaf
− leaf apex shape: tip of the leaf
− leaf base shape: base of the leaf where it connects to
the node
Leaf Venation
• Is a term used to describe the pattern in which leaf veins are
organized
• Is split into two principal types:
− parallel-veined leaves: numerous veins run parallel to each other
− net-veined leaves: veins branch from main midrib(s) and subdivide
into a complicated network of veins
Leaf Arrangement
• Is a characteristic used in identifying plants
• Describes the position and location of leaves on the stem of the
plant
• Occurs on the stem and on petioles
Leaflet Arrangement on Petioles
• May be broken down into two types:
− compound: many leaflets arise from the same petiole
• pinnately compound: leaflets arranged on both sides of a
stem
• palmately compound: leaflets radiate from a central
point
• double pinnately compound: double set of compound leaflets
Leaf Arrangement on Stems
• May be broken down into four types:
− alternate: staggered arrangement along stem
− opposite: leaf pairs arranged directly across from each other
− rosette: leaves located at base; arranged in a spiral
cluster
− whorled: leaves are arranged in a ring
. Flowers
- Are organs for sexual reproduction
- Produce gametes
- Play a key role in pollination
Flower Parts
• Include:
− peduncle
• flower stalk
− receptacle
• part of flower stalk bearing floral organs
− sepal
• leaf structures at flower base, protects young buds, all
together known as calyx
− petal
• located in and above the sepals, attracts
pollinators, all together known as corolla
− stamen
• male part of the flower, makes pollen grains
− filament
• stalk of the stamen, contains the anther
− anther
• bears pollen
− pollen
• grains containing the male sex cells
− pistil
• female part of the flower
− stigma
• sticky top of pistil, receptive surface for pollen
grains
− style
• stalk of the pisitl, where pollen tube grows
− ovary
• base of the pistil, matures to become fruit
− ovule
• located in the ovary, carries female sex cells
Plant Growth
• Includes the following stages: − germination − vegetative development − reproductive development • May be affected by the following: − water − light (red and blue light are absorbed and trigger plant growth; green light is reflected) − temperature − competition
Germination
• Requires the following external factors: − specific temps − moisture level − oxygen − light
Plant Hormones & Growth Regulators
• Can be compounds produced within the plant (phytohormones) or maybe manufactured compounds (plant growth regulators)
− auxin causes the plant stem to tip, known as phototropism
− cytokinins are used to prolong storage life
− gibberellins are applied to grapes to increase berry size and
produce looser clusters
− ethylene can be applied to a field of crops to ensure all
fruit will ripen simultaneously
Plant Processes
• Allow plants to produce their own food and adapt to changes in their environment • Include the following: − absorption − photosynthesis − respiration − transpiration
Absorption
• Occurs when water is drawn into the root and minerals dissolve
• Occurs in the endodermis
• Allows certain molecules to be absorbed and pumps out other molecules
• Is increased when surface area increases
− roots hairs: extensions of root cells
• increase surface area
− mycorrhizae: fungal associations with roots
• greatly increase surface area
Photosynthesis
• Is the process of carbon dioxide and water reacting with light energy to
form photosynthates and release oxygen as a byproduct
− requires light energy, CO2 and H2O
− occurs in the chloroplasts
• Carbon dioxide + Water Glucose + Oxygen
− 6CO2+6H2O C6H12O6+6O2
• Allows plants to make their own food and convert it to energy
Respiration
• Is the process of a cell releasing energy by breaking down
glucose and other food molecules in the presence of oxygen
• Is the opposite reaction of photosynthesis
• Creates a net energy production of 36 units of ATP
Transpiration
• Is essentially evaporation of water from plant leaves and is similar to perspiration in humans
The Cell Cycle
• Describes the life of the cell • Can be divided into two phases − Interphase • G1 phase • S phase • G2 phase − mitosis (M Phase) • prophase • metaphase • anaphase • telophase
Interphase
- Is where the cell spends the most of its time
* Is when the cell carries out most of its normal functions
G1 Phase
• Stands for Gap 1 phase • Is also known as a growth phase • Is the long period before mitosis in which the cell: − grows − carries out protein synthesis − performs other cellular functions
S Phase
- Is known as the synthesis phase
- Occurs after the G1 phase
- Is when the cell replicates its DNA
G2 Phase
- Stands for Gap 2 phase
- Is also known as a growth phase
- Occurs after the S Phase
- Allows cell to continue to carry out normal functions
M Phase
• Is also known as mitosis
• Is a process by which new cells are created
• Results in 2 daughter nuclei
− with genetic material identical to each other and the mother cell
Mitosis
• Is important for: − cell growth − cell replacement • cells are continually sloughed off and replaced − regeneration of plant parts − vegetative reproduction • continuous production of genetically identical cells and offspring • Steps include: − prophase − metaphase − anaphase − telophase
Prophase
• Is the 1st stage of mitosis
• Steps include:
− chromosomes condense and become visible
− centrosomes begin moving to the opposite ends of the cell known
as poles
• Steps include:
− nuclear membrane dissolves
− fibers cross the cell to form the mitotic spindle
− spindle fibers attach to each sister chromatid at the
centromere
Metaphase
• Steps include:
− centrosomes complete migration to the poles
− chromosomes align in the middle of the cell known as the equator
Anaphase
• Steps include:
− spindels attached to centromeres begin to shorten
• exerts force on sister chromatids and pulls them
apart
• Steps include:
− shortening of spindle fibers continues, pulling chromatids to
opposite poles
• ensures identical sets of chromosomes are applied
to each daughter cell
Telophase
• Steps include:
− chromosomes arrive at opposite poles of the cell
• new membranes form around daughter nuclei
− chromosomes and spindle fibers disperse
− nuclear envelope forms
− completion of cytokinesis
• two daughter cells are created
DNA
• Stands for deoxyribose nucleic acid
• Carries genes which contain genetic material
• Is located in the nucleus
• Stores and processes information in the cell
• Is made up of nucleotides which consist of:
− five carbon sugar (deoxyribose)
− nitrogen base attached to the sugar
− phosphate group
• Are building blocks of nucleic acids
Genes
• Are a sequence of DNA
− DNA: a tightly wound molecule found in chromosomes
• Code for a specific protein which is involved in the expression
of a trait
− allows them to produce hereditary traits in offspring
Plant Breeding
• Is the application of genetic principles to create or manipulate
significant traits in plant production
• Increases efficiency by combining desirable traits
− develop improved offspring
• Was explored by Gregor Mendel
− his experiments led to many discoveries in the science of plant
breeding
. Mendel’s Principles of Inheritance
• Include: − fundamental theory of heredity − dominance − segregation − independent assortment
Fundamental Theory of Heredity
• Proved when parent plants are crossed, dominant traits are always
apparent in the progeny
− recessive traits are hidden until after the 1st generation
• Proved traits remain distinct in successive generations
• Discovered inheritance factors are alleles which are different variants of the same gene
− includes:
• homozygous
• heterozygous
Homozygous Genotype
• Is when an organism has two copies of the same allele for a gene
• Includes:
− dominant: two dominant alleles for a particular trait
− recessive: two recessive alleles for a particular trait
Heterozygous Genotype
- Is when an organism has two different copies of an allele for a gene
- Is the combination of one dominant allele and one recessive allele for a particular trait
- Refers to an organism which exhibits the dominant trait but is a carrier of the recessive trait
Genetic Engineering
• Is also known as genetic modification or genetic improvement
• Is the process of moving genes from one organism to another
• Allows the transfer of useful characteristics by inserting genes from
another organism
• Includes:
− DNA extraction
− gel electrophoresis
− insertion of foreign DNA into a host plant
Process of Genetic Engineering
• Includes: − DNA extraction − gene cloning − gene design − transformation − backcross breeding
DNA Extraction
• Is the first step in genetic engineering
• Allows all of the DNA of an organism to be extracted at once
• Involves taking a sample containing a gene of interest
− is taken through a series of step which seperate the DNA
from other parts of the cell
Gene Cloning
• Is the second step in genetic engineering
• Is used to separate single genes of interest from the rest of the genes
extracted
• Involves the duplication of thousand of copies of the gene of
interest
Gene Design
• Is the third step in genetic engineering
• Relies on the One Gene, One enzyme Theory
− a single gene stores information which directs the production of a
single enzyme
• Involves cutting the gene with enzymes and replacing certain
parts
− ensures the gene to work once placed inside another organism
Transformation
• Is the fourth step in genetic engineering
• Is also known as gene insertion
• Involves trying to transport the gene and deliver them to the nucleus
without killing the cell
• Is a method by which recombinant DNA is made
104. Transformation
• Involves the success of a DNA being inserted into the chromosome
− cells which receive the new gene are known as transgenic
• Involves the use of tissue culture to spread masses of plant
cells
− since inserting a copy of the transgene into millions of cells is not
possible
Backcross Breeding
• Is the final step in genetic engineering
• Involves the crossing of transgenic plants with elite breeding lines
− combines desired traits and the transgene into a single line
• Involves the offspring to be repeatedly crossed back to the elite line
− used to obtain a high yielding transgenic line
• Results in a plant with high yield potential which express the
trait encoded by the transgene
Structure & Function of Organic Molecules
• Include: − proteins − carbs − lipids − nucleic acids
Proteins
- Are made up of amino acids
* Serve as structural elements in the cytoskeleton
Carbohydrates
• Are composed of carbon, hydrogen and oxygen
• Perform the following functions:
− energy metabolism in cells
− composition of the cell wall (cellulose)
− storing and yielding energy
Lipids
• Provide structure in:
− cellular membranes
− chloroplasts
. Soil
• Is the necessary medium for nutrient distribution; water and chemical consumption; and plant stability • Requirements include: − orgainisms to help cycle nutrients − nutrients and minerals − water • Note: A good all-around soil is a loam, a mixture of sand, silt and clay
Soil pH
• Is the measurement of the alkalinity or acidity of soil • Is measured on a scale of 0-14 − acidic: less than seven − basic or alkaline: greater than seven − neutral: 7
Environmental Factors Affecting Plants
• Include:
− hail
• removes anatomical features and inhibits future growth
− cold weather or freezes
• cell damage and death
• widespread phosphorus deficiency problems
• some plants can do well below freezing temperatures
− carrots
− blueberries
− spinach
− heat • wilting leaves − flooding • can eliminate a plant’s ability to utilize respiration − lightning • burns plant cells and tissue • can cause necrosis − fires • burns plant cells and tissue
Hydroponics
• Is the production of plants without a soil medium
• Utilizes only water, sunlight and nutrients
• Is used to efficiently produce plants when soil mediums are not desired,
needed or available
• Is utilized within greenhouses in areas with environments not suitable
for plant production
Pests
• Are any life forms competing for resources
• Are plants or animals detrimental to humans or human concerns
• Are an organism which pose a threat to other organisms’ health
• Are parasites:
− organism which lives on or inside another organism
− obtains nutrients from host
− detriment to the host
• Can be any of the following: − insects − vertebrates − nematodes − weeds − pathogens • fungal • bacterial • viral
Disease
- Is any condition interferring with normal growth and development
- Is caused by living or non-living agents
- Can affect any area on a plant
- Note: fungi, Bacteria and Viruses are all types of pathogens
Disease: Living Agents
• Are referred to as plant pathogens − anything causing harm to plants • Include microorganisms, such as: − fungi − bacteria
Fungal Diseases
• Spread from plant to plant via wind, insects, rain, soil and machinery
• Can be transmitted by seeds
• Can be waterborne
• Are most common and easiest to treat
• Treatment can include:
− sanitation
− reduce watering
− increase air flow
6. Fungal Diseases
• Usually start with spotted or discolored leaves and stems
− dry, brown margins and dead tissue or necrotic lesions
• Are controlled with dusts or sprays
• Are nearly impossible to eliminate if not treated immediately, especially
soil-borne disease
Life Cycle of Fungi
• Includes four stages: − spore production − spore − spore germination − hyphal growth
Boll Rot
• Scientific Name: Gibberella Fujikuroi
• Characteristics:
− begins as small black spots on bolls of cotton and rice
• white mold may also appear
− eventually affects entire boll
− causes bolls to appear black or brown and have a very hard
surface
− results in bolls opening too early or not at all
• Environmental conditions:
− wet weather
− humidity
Corn Smut
• Scientific Name: Ustilago maydis • Characteristics: − occurs on ears, tassles, nodes, internodes, leaves and aerial roots − forms large, white masses called galls − can grow up to five inches in diameter
Crown Rot
• Scientific Name: Sclerotium delphinii • Characteristics: − occurs in wide range of plants − develops brown areas in the root cortex and crown − stunts plant growth − affects entire plant − causes plants to wilt and die − can cause drastic reductions in crop yields
Damping Off
• Scientific Name: Pythium Spp. • Characteristics: − attacks seeds before germination − causes seeds to decay − seeds become soft and dark-brown − most infected seeds never sprout − affects germinating seeds 12. Damping Off • Characteristics: − seeds shrivel and darken − causes seeding stem tissue to weaken and decay − affects mature plants at soil level − plants begin to wilt and fall over
Downy Mildew
• Scientific Name: Albugo spp., Bremia spp., peronospora spp., Pseudoperonospora spp. • Characteristics: − is found on many vegetable crops − initially infects leaves − turn yellow or brown − white or purple mold spots appear on underside of leaf • Environmental conditions: − cool, wet weather − high humidity
Early Blight
• Scientific Name: Alternaria solani • Characteristics: − is common in potatoes and tomatoes − forms small, dark-brown spots on leaves, which enlarge and merge together − causes leaves to die − covers potato tubers with brown spots − is also found on stems and fruit of tomato plants
Gray Mold
• Scientific Name: boytris spp.
• Characteristics:
− is also referred to as Botrytis blight or Botrytis fruit rot
− infects an array of vegetables, herbaceous and woody plants
− forms masses of gray or brown spores on leaves
Mildews
• Are a form of mold
• Are commonly found in damp, moist, shaded places
• Affect leaves, stems, buds, flowers and fruits
− leaves will turn pink, blue or purple and drop prematurely
• Are usually white, gray, green or black
Bacterial Diseases
• Are easier to prevent rather than cure
• Enter plants through wounds or natural openings, such as the stomata
• Easily occur under the following conditions:
− high humidity
− poor air circulation
− irregular watering
− poor soil drainage
− fluctuating temperatures
Disease: Non-Living Agents
• Include: − environmental stress on plants, such as: • air pollution • drought • hail • wind − cultural care − toxic chemicals − viruses
Viruses
• Are microscopic, infectious agents consisting of a protein coat surrounding nucleic acid • Multiply in cells of living hosts • Are recognized by the following symptoms: − leaf curling − leaf discoloartion − ring spots on leaves − stunted growth • Can be prevented by: − planting disease-resistant varieties − controlling pests carrying viruses − removing and destroying infected plants − controlling weeds − handling foliage when dry • Can be spread by: − infected insects, plants and microorganisms
Mosaic Virus
• Characteristics: − affects tomatoes, cucumbers and soybeans − affects plants at all growth stages − causes leaves to curl and turn yellow − stunts plant growth − deforms fruit − forms blister-like infections on leaves and molting occurs − can be spread by the following: • infected seeds • contaminated tools and equipment • infected crop debris • Environmental conditions: − transmitted by inscets • Prevention methods: − plant disease-resistant varieties − control insects carrying the disease − remove and destroy infected plants − control weeds • Treatment methods: − no known treatment is available • follow prevention methods
Insects
• Are members of the arthropada phylum • Damage lawns, crops and other plants by feeding off roots, leaves and fruits • Can spread disease among plants • Are members of the class Insecta − class characteristics include: • 3 pairs of legs • three body segments • two pairs of wings (typically) • one pair of antennae • one pair of eyes − examples include: • ants, bees, beetles, butterflies, crickets, fleas, flies, moths • Are not always considered pests − insect pollinators are essential to plant growth and reproduction − other insects serve as predators and help control harmful insects • Can be classified into two categories: − sucking (ex: Aphids) − chewing (ex: Caterpillars)
External Structure of Insects
• Consists of the head, throax and abdomen
− the head includes eyes, antennae and mouthparts
− the thorax includes legs and wings
− the adult abdomen has no legs or wings
Complete Metamorphosis
• Consists of four stages: − egg • female lays egg − larva • worm-shaped • eating and growing stage − pupa • develops into adult while in a cacoon • grows wings and legs − adult • breaks out of cocoon • has identifiable insect features
Incomplete Metamorphosis
• Consists of three stages: − egg • female lays hundreds of eggs • eggs are white or yellow • eggs hatch within 20 days − nymph • is the growing stage • looks similar to adult insects − adult • has developed all identifiable insect features • adults mate, females lay eggs, and the entire process repeats
Aphid
• Characteristics: − green, yellow, red, pink or black in color − young have wings, mature are wingless − produce toxic saliva • referred to as honeydew − presence can go unnoticed − feed primarily on garden plants • Effects on plants: − distorts leaves • curling • discoloration • leaves may fall off − stunts plant growth − may cause death
Lace Bug
• Characteristics:
− adult is approximately 1/8th inch long
− light-colored body
− clear wings
• Effects on plants:
− yellow and brown spots on top of leaves
− severely injured leaves drop from plant
• Prevention methods:
− allow natural predators, such as ladybirds and green lacewings, to
provide control
− plant resistant varieties
Mealybug
• Characteristics: − less than a quarter inch length − white body with long, white “tall” filaments − males have wings − appear in greenhouse and nursery crops • Effects on plants: − wilts plants by extracting sap − discolors leaves − causes leaves to drop prematurely − stunts plant growth − can result in death
Whitefly
• Characteristics: − very small − pale-yellow body with white wings − usually in groups − prefer the underside of leaves • Effects on plants: − feeds on plant phloem − turns leaves yellow • particularly cotton, poinsettia and vegetable plant leaves
Nematodes
• Are very small roundworm
− may be parasitic or beneficial
• Are important decomposers in soil
• Damage vascular tissue of plants, preventing nutrient dissemination
• Create wounds, causing susceptibility to other diseases
• Note: foliar nematodes eat holes through leaves of plants
Pest Control
• Is based on effectiveness and risk • Include: − highly selective chemicals − targeted spraying − broadcast spraying • Note: Integrated pest management is an effective and environmentally sensitive approach to pest management which relies on a combination of common sense practices
Techniques of Pest Control
• Biological controls
− pest control which is non-toxic to plants, humans and
wildlife
• examples: mulches, crop rotation, planting density, proper irrigation
− use beneficial insects to control pests
• example: introducing ladybugs to control aphid populations
• Cultural controls
− simple to use and inexpensive
• examples: mulches, crop rotation, planting density
• Mechanical controls
− use physical methods, such as insect and animal traps, to reduce weeds and control pests by spreading less seeds
− are less effective and impractical on a large scale
• Chemical controls
− use biological, natural and synthetic pesticides to control pests
− can be harmful to environment if not applied correctly
• pyrethyroid is least toxic to the environment
• Host-plant resistance
− use plant varieties resistant to attack of pests and diseases
• plant breeders breed plants for certain traits making the plant resistant
• regulatory controls
− contain and eliminate pests already established in limited areas
− prevent introduction of pests from foreign countries
− restrict entry of any infested goods
Pesticides
• Reduce, prevent, repel or eliminate pests • Control pests in landscapes, gardens, field crops and homes • Protect plants, animals and humans • Are classified by type: − algaecides • control algae − anti-microbial • control bacteria and microorganisms − avicides • control birds − fungicides • kill fungi − herbicides • kill weeds • Are classified by type: − insecticides • kill insects and other arthropods − insecticides • kill snails and slugs − nematacides • kill nematodes − repellents • repel pests including insects and birds − rodenticides • control rodents
Vertebrates
• Are distinguished by the possession of a backbone or spinal
column
Deer
• Eat and damage a variety of plants including: − garden vegetables − grasses − forbs − fruits − shrubs − trees • trample trees and shrubs • Rub antlers against trees
Raccoons
• Feed on fruits, berries, nuts, corn and other grains
Squirrels
• Cause damage by feeding on seedlings of vegetable plants in
gardens
• Damage fruit trees by feeding on fruits and nuts
• gnaw on the bark of trees and shrubs
Weeds
• Compete with desirable plants for nutrients, water, sunlight and spacing • Without adequate water will wilt, droop or shrivel • Have one of three life cycles: − annual − perennial − biennial • Can be beneficial: − soil stabilization − habitat and feed for wildlife − addition of organic matter
Annual Weeds
• Complete a full life cycle, from germination to seed production, within one year • Include: − crabgrass − annual bluegrass − chickweed − pigweed
Biennial Weeds
• Have a typical life span of 2 years
• Produce only roots, stems and leaves the first year
• Flower and produce seeds in the second year
• Include:
− common burdock
− Queen Anne’s lace
− bull thistle
Perennial Weeds
• Will live for several years and flower more than once • Produce seeds annually • Usually have deep root systems • Examples include: − dandelions − white clover − Bermuda grass − stinging nettle
Bull Thistle
• Scientific Name: cirsium vulgare • Characteristics: − widespread biennial − can grow two to six feet tall − pink colored flower on top of stems − grows in sunny, open areas − long, sharp spines on leaves − reproduces only by seed − taproot system
Chickweed
• Scientific Name: stellaria media • Characteristics: − winter annual − white flowers − edible − leaves and stems are hairy and give a sticky feeling − similar to sticky chickweed − grows upright
Common Sunflower
• Scientific Name: helianthus annus
• Characteristics:
− summer annual
− can grow one and one-half to eight feet in height
− coarse/hairy leaves and stems
− heads can reach five inches across
− flowers are yellow and brown or maroon in center
− heads of flowers follow the sun each day
Crabgrass
• Scientific Name: digitaria spp
• Characteristics:
− annual
− found in all areas
− smooth crabgrass is low growing
− reaches approximately six inches tall
− leaves grow up to five inches in length
− spread by seeds through factors, such as wind and water
− range from one-half to two and one-half inches depending on type
of grass
Horsenettle
• Scientific Name: solarum carolinense • Characteristics: − perennial − stems may grow three feet in height − poisonous to livestock • even when consumed in hay − deep spreading root system − leaves contain prominent thorns − produces a green berry which turns yellow and wrinkles with age
Pigweed
• Scientific Name: amaranthus
• Characteristics:
− summer annual
− grows erect and can reach six and one-half feet in height
− stems are often red in color especially at base
− leaves are about one-half an inch in length
− small, green flowers are densely packed at top of stems
Herbicides
• Chemicals which kill plants or inhibit their normal growth
• Most effective when good cultural practices are in place
• If improperly applied can become hazardous to plants
• Combinations vary with use and environmental factors:
− agronomic
− ecological
− economic
• Contact herbicides:
− effective against annual weeds
− only kills plant parts which chemical comes into contact
• systemic herbicides:
− effective against annual and perennial weeds absorbed by root or
foliar parts of plants
• postmergent herbicides:
− affect a plant which is actively growing
The United States
• Has 2.2 million farms and less than five percent are managed by nonfamily owned corporations
• Will have to double agriculture output by 2050 to meet global
food demand
• Produces more corn than any other country
Seasonal Crops
• Include: − warm season • corn • tomatoes • watermelons • Warm Season Crops: crops harmed by frost and which grow best at temperatures above 70 F (21°C) 3. Seasonal Crops • Include: − cool season • onions • potatoes • wheat • Cool Season Crops: crops which grow best at temperatures between 60 F to 65°F (15°C to 18°C)
Grains
• Include: − warm season • corn • sorghum − cool season • barley • cereal rye • oats • ryegrass • triticale • wheat
Vegetables
• Include: − warm season • eggplant • peppers • sweet potatoes • pumpkins • tomatoes − cool season • asparagus • broccoli • cabbage • carrots • cauliflower • celery • lettuce • onions • potatoes
Fruit Crops
• Include: − apples − blackberries − blueberries − cherries − cranberries − olives − peaches − pomegranates − raspberries − strawberries
Oilseed & Special Purpose Crops
• Include: − canola − corn − flaxseed − soybeans − sunflower seeds
Forage Crops
• Include: − alfalfa − hay − prairie grass − red clover − ryegrass − sorghum
Field Crops
• Include: − barley − cottonseed − hay − oats − tobacco − wheat • Field Crop: crops other than fresh fruits or vegetables grown for agricultural purposes
Nut Crops
• Include: − almonds − chestnuts − hazelnuts − macadamia − peanuts − pecans − pine nuts − pistachios
Fiber Crops
• Are grown for their fiber to make paper, cloth or rope • Include: − bamboo − cotton − flax
Row Crops
• Include: − beans − blueberries − corn − cotton − flax − peanuts − potatoes − pumpkins − sorghum − soybeans − sunflowers − watermelons − wheat
Sugar Crops
• Include: − maple syrup − sugar beets − sugar cane − tropical maize
Fertilizers
• Are a source of plant nutrients used to supply one or more of the
essential nutrient elements to the plant
• Are labeled with 3 numbers, showing the percentage by
weight of available nitrogen, phosphate and potash which is defined as
the fertilizer analysis or grade
• macronut: required in a relatively large proportion for growth and
development of plants
• Micronutrients: required in smaller amounts
Fertilizer Analysis
• Is located on the label of the fertilizer bag and is usually expressed as NP-K
− example: 8-0-28 = 8 percent nitrogen; 0 percent
Phosphate; 28 percent Potassium
• in a 100 pound bag = 8 lb. Nitrogen; 0 lb. phosphate;
28 lb. Potassium
• in a 50 pound bag = 4 lb. Nitrogen; 0 lb. Phosphate; 14 lb.
Potassium
Water
• Has the following chemical properties:
− cohesion
• allows water to stick to water
− adhesion
• allows water to stick to other materials
− surface tension
• allows water to assume the shape having the least
surface area
• Capillary action: allows water to move within the space of a porous
material due to the forces of adhesion, cohesion and surface tension
Watersheds in the United States
• Are found on every acre of land
• Can be virtually any shape or size
• Join to form larger watersheds which drain into even larger bodies of
water
• Occur mainly on two types of terrain
− steep terrain
• water drains into fast-moving streams and swift rivers
− flat terrain
• water drains into ponds, lakes, creeks and swamps
• Watershed: area of land between two high points, where all water drains
to a common area below
Watershed: Water Sources
• Occur in two main forms
− groundwater water
− surface water
Ground Water
• Is contained in a subterranian area of saturated soil and rock called
an aquifer
− water flowing naturally from the earth due to an overflowing aquifer
is a spring
• Is prevented from seeping deeper underground by a layer of
impermeable rock
• infriltration: water seeping into the ground surface
Surface Water
• Includes all areas of visible water on the landscape
• Is found in water features such as lakes, reservoirs, rivers, streams and
wetlands
• Can serve as both a recharge source or a discharge area for ground
water
• reservoir: a lake created by placing a dam on a river
Surface Water Measurement
- The rainfall volume of a watershed is calculated in acre inches
- Rainfall volume equals: acres in a watershed X inches of rain
Acre Feet
• Is used to calculate the volume of surface water bodies such as
reservoirs and lakes
− to calculate acre feet you will need some information on the water
body which includes:
• surface area
− calculated by multiplying length times width
• average depth
− calculated by averaging multiple depth measurements
Groundwater Measurement
• Can be difficult due to a number of factors including: − hydrogeological • ground water features − hydrological • climate water features − climatological • earth’s climate features
Watersheds
• Are negatively impacted by many factors including:
− floods
• transport non-point source pollutant
− droughts
• increase the demand on existing water resources
− irrigation
• can have multiple impacts on ground water including:
− receding land
− increasing aquifer salinity
− accelerated ground water pollution
Water & Watershed Conservation
- Is fundamental to ensuring the future availability of water
- Can be practiced by everyone
- Can save thousands of gallons of water each year
Indoor Water Conservation
• Can be accomplished in a variety of ways including: − fixing household leaks − taking a shower instead of a bath − wash only full loads of laundry − reusing clean household water − defrosting food in the refrigerator
Outdoor Water Conservation
• Can be accomplished in a variety of ways including:
− turning off irrigation during a drought
− install a rain shut-off device to your irrigation system
− following local water use restrictions
− applying thick layers of mulch to decrease water evaporation from
the soil
− incorporating drought tolerant plants into your landscape
Watershed Conservation
• Can be accomplished in a variety of ways including:
− maintaining proper levels of vegetation and ground cover
− monitoring livestock grazing intensity
− controlling water runoff and preventing soil erosion
− proper application and disposal of chemicals and fertilizers
