Basic Agronomy/Plant Biology Flashcards
What is required for photosynthesis?
sunlight, chlorophyll, water, CO2, heat, nutrients, structure (usually soil)
What are the stages of plant growth?
- planting
- care of the growing, vegetative plant
- development of seeds
- harvesting and storage
What is dormancy?
seed won’t germinate even in favorable conditions
What is quiescence?
stage of inactivity in the seed, will end if conditions are favorable
What is imbibition?
water uptake
What is needed for a seed to germinate?
water, proper temperature, nutrients (N&P), energy source (CHO, lipid), proper depth
What happens if you plant a seed too deep?
it might run out of energy before reaching the surface where it can become an autotroph
What happens if you plant a seed too shallow?
it might blow away , get eaten, or dry out
might not be able to use soil moisture, especially if the seed-soil contact is poor
What is an autotroph?
an organism that can meet its own nutritional requirements through inorganic compounds (CO2)
What is a heterotroph?
an organism that needs organic compounds to meet its nutritional requirements
What are the parts of a seed?
seed coat, endosperm, embryo
What is a monocot?
has one leaf upon emergence, grasses
makes it easier to break through the soil surface
ex) corn, barley, wheat
What is a dicot?
has two leaves upon emergence, broadleaf
bends more upon emergence
ex) soybean, peas, legumes
How do C3 and C4 plants differ?
have different affinities for CO2
C3 has a lower affinity
C3 - cool season (rye, small grains)
C4 - warm season (corn, sorghum)
What conditions influence photosynthesis?
CO2 concentrations, light intensity, temperature, water availability in the soil, plant architecture
What are photosynthates?
products from photosynthesis
ex) leaves, silks, grains
When does photosynthesis stop?
when the stomata closes - when there is a lack of light and water
Why do plants keep their leaves at an angle?
to make the largest surface for sunlight
What is Langleys?
a measure of light intensity to rate of photosynthesis
has regions of deficiency, saturation and damage
What is LAI?
leaf area index
area of leaves/area of soil surface (shadow area)
different plants use different architecture to maximize sunlight
Why is a closed canopy desirable?
closed canopy = overlapping between rows
it shades out weeds, captures more sunlight (isn’t hitting the ground)
What are the steps of seed development?
flowering –> pollination –> seed set
Why is moisture content important for harvest and storage?
grain/seed can be damaged during harvest if too dry or wet
ex) corn - 26% or less, soybeans - no lower than 14%
grain/seed can spoil if too wet during storage
ex) corn - 14%, soybeans - 12%
What are the steps of harvesting grain?
cutting
threshing - loosening grain from husks and straw
winnowing - separating grain and chaff
How is perennial forage for silage stored?
harvested moist
clippings packed airtight into a bunker silo
anaerobic respiration pickles silage (fermentation)
How is hay harvested and stored?
cut, loosened, drys out to 15% moisture content, then baled
stored outside or in a pole barn
What are the two tissue types?
woody, herbaceous
How can plants be categorized?
botany - seedling morphology, tissue type, photosynthetic pathway
reproductive method
parts of the plant that are used
lifespan - annuals, perennials, biennials
planting pattern
market use
What are the possible market uses of plants?
commodity, specialty crop, food (vs feed)
What are annuals?
one growing season
winter (require cold period) and summer annuals
What are perinneals?
live for years
ex) trees, alfalfa
What are biennials?
two years to complete cycle
ex) artichokes, garlic
What are the different planting patterns?
row crop
narrow or solidly seeded
sod (stolons, rhizomes, hay)
What is a rhizome?
continuously growing horizontal underground stem that puts out lateral shoots
What is a stolon?
creeping horizontal plant stem or runner that takes root at points along its length to form new plants
What are different propagation methods?
seeds (sexual), clippings (herbaceous), cuttings (woody; i.e. grafting), seedlings/transplants, bulb (clone), tubers (i.e. stolons, rhizomes, clones), tissue culture (i.e. chunk of potato), spores (mushrooms)
What are various parts of the plant that can be used?
seed, leaves and stems, roots, flower, fruit, nuts, sap, bark, fungi, herbs (whole plant), sprouts
What is involved in field preparation?
plowing, incorporation of cover crops, adding amendments (manure, compost), secondary tillage, removal of rocks, possibly initial herbicide application
What are important considerations for timing?
temperature, soil moisture, frost, field conditions adequate for traffic
