Field Crops Unit 2 Exam

Agronomic Crops

Cereal crops, Grain crops, Pulses, Forages, Hay, Silage, Fiber crops, Main crops, Root and Tuber crops, Cover crops, Companion crops, Green Manure crops.

Cereal Crops

Grasses that produce edible grain, Name derived roman goddess - ceres. Rice, Corn, Barley, Sorghum. 75% - starch, 12% - protein, 2% - fat, as well as vitamins and minerals.

Grain Crops

Harvested fruit or seed of several crops. Crops include corn, legumes, flax, and buckwheat.

Small Grain

Oat, Barley, and Rye, seeds are small relative to corn.

Pulse crops

Derived from latin word puls, thick soup. Legumes grown for edible high protein seeds. Some are high in protein and fibers and others are low in fat. They are harvested as dry grain. seeds are borne in pods that split in half when mature and dry.

Types of Pulse Crops

soybean, dry bean and field bean, field pea, lentils, peanuts, chickpea, cowpea. Food and agricultural organizations recognize 2 types of pulses.

Forages

Crops used for livestock feed, livestock consumes stems leaves sometimes seed or grain. Alfalfa, clovers, and grasses.

Hay

Forage that is dried - 20% moisture and stored

Silage

Harvested at 50 - 80% and stored in a seal structure, ferment under anaerobic conditions.

Fiber crops

Plants used to make clothing, rope, paper, and baskets. Fiber cells are extracted from the plants.

Main Fiber crops - Cotton

mostly cellulose and is white

vary in length and are twisted

most widely used natural fiber crops.

Main Fiber Crops - Flax

called bast because it is found in the plant stem.

cloth produced is linen

oldest crop used for fiber and crop production

fiber length average about 2 feet

70% cellulose and some wastes

Main Fiber crops - Hemp

Produces best fiber

coarse and brown

used for canvases, rope and bags due to strength

Main Fiber Crops - Ramie

bast fiber

found in bark of plant

perennial

Root and Tuber crops

Harvested for underground storage organs that are rich in starch

Root and tuber crops - potato

tuber

sweet potato and cassava - enlarged root

Cover crops

grown to cover soil

often grown after a small grain crops

experimenting - growing with corn and soybeans, growing after sugar beet harvest.

often use cool season plants - rye, radish, turnip, hairy vetch

Companion Crops

Planted with another crop to be harvested at maturity or immature

companion crops help prevent soil erosion and control weeds

small grain planted with alfalfa - may be harvested at maturity or immature for hay or silage - alfalfa will regrow.

Green manure crops

Crops returned to soil while vegetative - tilled

legumes and grasses are traditionally used

add nutrients and improve soil quality

crops - sweet clover, alfalfa, hairy vetch, crimson clover, winter rye.

Recreational Turf

Kentucky bluegrass

perennial ryegrass

fine fescues

tall fescues ( turf type)

Nutritional Use Crops

Sugar crops, oil crops, protein crops.

Sugar crops

sugar beet

sugar cane

corn

sweet sorghum

Sugar beet and Sugarcane

sucrose, crystal or liquid

molases

Sweet Sorghum

stalked crushed and liquid extracted

evaporated to produce syrup

Corn

high fructose corn syrups

starch converted to fructose-glucose mixture

Oil Crops

crops producing oil rich seeds

soybean, flax, sunflower, canola, peanuts, cotton

Protein crops

high in protein

usually legumes

starchy seed crops

high in starch

cereal crops

amaranth and buckwheat

starchy root and tuber crops

root or tuber high in starch

starch converted to energy when eaten

Bioenergy

Production of energy from biological systems

biomass crops - burned heat and electricity, hybrid poplar, switchgrass, miscanthus.

Biofuel

produce liquid fuels

crops - corn, grain, sorghum, soybean

ethanol - sorghum and corn

oil - soybean - biodiesel

pennycress - bio jet fuel

Medicinal

contain compounds with specific properties

pain relief, hallucinogenic, disease treatment

Medicinal Crops

white willow - salicin - pain

opium poppy - morphine

purple foxglove - digitoxin (heart failure)

marijuana - THC - tetrahydrocannabinol

coffee - caffeine - stimulant

Toxic Plants

Monkshood - aconitine - heart failure/asphyxiation

castor bean - castor oil, industrial lubricant, contain ricin - extracted during oil production, no known antidote.

Jimson Weed - leaves and seeds - atropine, hyoscyamine, scopolamine. - vision problems, hallucinations and euphoria, seizures and breathing problems.

Naming plants - taxonomy

system of organizing all life based on similar genetic or morphological characteristics

Naming Plants - scientific name

universal plant identification

binomial nomenclature developed by carl linnaeus

plants names using genus and species

soybean - glycine max L - L is short for linnaeus - person that named soybean

Classification - monocots or dicots

monocots have one cotyledon within the seed

dicots have 2 cotyledons within the seed

Morphology

study of the form and structure of plants - flowers roots stems and leaves

anatomy

study of the internal tissues and cells of plants - epidermis, vascular system, meristems and grand tissues - tissue constructed of individual specialized cells

Monocot

1 cotyledon

parallel venation

vascular bundles scattered in stem

fibrous root system

hypogeal germination

simple branching

floral parts mostly in threes

Dicot

2 cotyledons

herbaceous and woody

netted venation

vascular bundles in a ring

taproot system

usually have epigeal germination

complex branching

floral parts in fours and fives

Epidermis

outer protective layer on leaves and stems

usually covered by cuticle - waxy covering reduces water loss and provides protection from attack by pests

stomata

small openings in the epidermis that allow for gas exchange - water vapor, carbon dioxide, and oxygen

two guard cells

can open and close based on environmental factors and plant needs

more numerous on the underside of the leaves - corn and soybeans leaves have more than 30k stomata per square inch on the underside of the leaves.

xylem and phloem

make up vascular bundles in plant stems, leaves and roots

conducting tissue

move under and nutrients throughout plants

xylem

moves water and minerals from the roots system to other parts of the plants

phloem

transports photosynthesis and other organic compounds throughout the plant

movement in both directions

arrangement of xylem and phloem is different in monocot and dicot plants

Ground tissue

tissue other than epidermal and vascular

composes the bulk of the plant - pith and cortex

cells - parenchyma, collenchyma, sclerenchyma

parenchyma

found in root stems and leaves

collenchyma and sclerenchyma

thickened cell walls and provide structured support

contain cellulose and lignin - make up fiber

meristems

areas of actively dividing cells in plants

apical meristems

located @ the tip or apex of a shoot or root

apical dominance occurs when the apical meristem inhibits axillary meristems from developing

axillary meristems

develops buds for branches or flowers

plant tissue - intercalary meristem

found in grasses and independent from apical meristems

responsible for the growth of the stem internodes and leaves

located at the base of the internodes, base of the leaf sheath and base of the leaf.

Plant tissues - secondary meristems

responsible for lateral growth

2 types of secondary meristems

• cork cambium

• - often found in woody plant stems

• - produces tissue to replace epidermis

Vascular cambium

• found in stems and roots of dicot plants

• increases stem diameter

Plant organs

three vegetative organs

• roots

• stems

• leaves

flowers are modified leaves

roots

anchor of plants

absorb water and minerals from soil

provide storage of energy reserves

Stems

supporting structure for leaves, flowers, and fruits

conduit for movement of water nutrients and photosynthate

may conduct photosynthesis and store energy

stems have nodes and internodes

modified stems

Rhizome - underground modified stem

stolon - above ground modified stem

bulb - swollen underground stem - concentric rings

corm - compressed, fleshy underground stem

tuber - enlarges fleshy stem, significant amounts of carbs

leaves - monocot

sheath collar and blade

ligule and auricle

Leaves - dicot

simple or compound

attached with a petiole

Flowers

modified leaves that many retain leaf like characteristics

consist of 4 parts - stamen, pistil, petals, and sepals.

complete flowers

consist of all 4 parts

incomplete flowers

lack 1 or more parts of a flower

perfect flower

have stamen and pistil present - soybean and alfalfa

imperfect

incomplete - monoecious, diecious

monoecious

staminate and pistillate flowers are on the same plant - corn and common ragweed

dioecious

staminate and pistillate flowers on separate plants - water hemp

Photosynthesis

plants convert energy from sunlight into chemical energy

chemical reaction

final product is glucose - used in metabolism, converted to more complex compounds.

pigment is chloroplasts - chlorophyll a and b. other pigment - yellow and orange

two reactions - light reactions and carbon fixation reactions

photosynthesis - light reactions

require light

photons (light energy) strike chlorophyll causing reaction

water is split into hydrogen and oxygen

two compounds are present - ATP, NADPH

ATP and NADPH

used in carbon fixation reaction

co2 moves in from stomata

power the transformation of carbon dioxide to simple sugars

c3 cycle

c3 plants

temperate regions are mostly c3

alfalfa, wheat, soybean, smooth broom grass.

subtropical plants - cotton, peanuts, tobacco

photosynthesis is inefficient in high temps and when carbon dioxide levels are low - stomata is closed. - photorespiration is caused by low CD levels.

C4 plants

different leaf anatomy

carbon dioxide fixed into a 3 carbon compound

first compounds formed are 4 carbon compounds

more water efficient

10% of plants have this pathway - corn, sorghum, big bluestem, switchgrass

respiration

conversion of sugars formed during photosynthesis to energy, ATP for use in metabolism of living cells, - repair, growth and maintenance.

occurs in cytoplasm and mitochondria

glucose and oxygen are transformed into carbon dioxide, water and energy.

4 primary processes

respiration - glycolysis

takes place in cytoplasm

glucose split into 2 three carbon molecules (pyruvate)

Produces ATP, NADPH, and water

pyruvate moves into mitochondria and is split into carbon dioxide and acetyl CoA

krebs cycle - respiration

uses acetyl CoA to produce ATP and NADPH

Respiration - final step

oxidative phosphorylation - occurs in membrane of the mitchondria

transpiration

process of water loss from stomata

driven by the sun’s energy and moisture concentration gradient

Function of transpiration

plant cooling

movement of nutrients within the plant

uptake of mineral nutrients

as water is lost through stomata more water is being pulled into the roots.

water movement of plants during transpiration

water moves from high potential energy to low potential energy

root hairs absorb water and dissolved minerals

xylem - travels up through the plant and exist in stomata

affected by soil moisture content, temp, humidity, wind, number of stomata

hot, dry windy days and low humidity will cause plant to use more water.

evapotranspiration

accounts for water loss by evaporation and transpiration

LBS of water for plants

proso millet - 589 lbs of water - produce 2.2lbs of dry matter

alfalfa - 1892 lbs of water - produce 2.2 lbs of dry matter

Stomata

underside of leafs

leaf hairs shade stomata, reducing leaf temp and reduce water vapor loss from leaf.

symbiotic nitrogen fixation

mutually beneficial relationship between plants and bacteria - rhizobia

plants provide nutrients and energy to bacteria while bacteria produces ammonium that is used by the plant.

if enough N is available, plants may reduce nitrogen fixation.

nodule formation

root cell division is stimulated that forms nodule

N fixed in nodule enter plants vascular system

photoperiodism

reaction of a plant due to the changing duration of darkness

pigment that senses change in red and far-red light

(phytochrome)

Phytochrome

Active form of phytochrome - phytochrome far-red

inactive form of phytochrome - phytochrome red

flowering

affected by light in several plant species

categorized by flowering response

short day, long day, day neutral. - photoperiod

Photoperiodism

long day plants - flower when photoperiod is longer than a certain period

day neutral - flower after a certain age or certain level of growth achieved

vernalization - exposure to cold temperatures to induce flowering

crops growth

increase in weight or size of an organism due to increase in number and size of cells.

Crop growth - developments

germination, seedling, vegetative, flowering and seed maturation

measurement of growth - fresh weight, dry weight, height, leaf area

Growth - dry matter

weight of all components minus water

development stages

seed, seedling, vegetative, flowering, fruit, seed, senescence.

growth stages

1 - 11

1 = first leaf stages

11 = grain ripening stages

2 adoks

haun

GDD corn

base temp of 50 degrees, 85 day relative maturity, 2100 GDDS

reproduction of plants

fusion of male and female reproductive cells called gametes

self pollination

pollen transferred to stigma of the sane flower

need to emasculate flower

cross pollination

pollen transferred to stigma on another plant

pollen and stigma mature at different times

self sterility or incompatibility - cannot self pollinate

male and female flowers on separate plants

monoecious plant with imperfect flowers

Nucleus of a cell

contains chromosomes that control inheritance

chromosomes made of deoxyribonucleic acid

DNA

DNA organized into units called genes

Genes determine all metabolic activities of a cell

genes composed of nucleotides

nucleotides

adenine

thymine

cytosine

guanine