Test #1 Flashcards
When do the two types of annuals germinate, flower, set seed?
Summer annual (SA)
Germ - spring
Flower - summer
Seed - fall
Winter annual (WA)
Germ - fall
Flower - spring
Seed - summer
How do simple and creeping perennials reproduce? When do you control each type? (3)
Simple - seed and taproot (control in early spring or early fall)
Creeping - seed and vegetative reproductive growth
creeping broadleaf - 2-4 leaf, early flower bud
creeping grass - 4-5 leaf
When do you control both types of annuals?
SA - spring/early summer
WA - fall
What are the 4 main difference between sedges and grasses
- Grass has a ligule, sedges do not
- Grasses have a split sheath, sedges are not split
- Grass leaves have one attachment point, sedges have 3
- Grasses have hollow internodes, sedges are solid
What are the symptoms that competition for light, nutrients, and water induces in plants?
Light - thinner cuticle, less “green”, elongation of internode
Nutrients - N chlorosis, P deep purple/green, K chlorosis on older leaf margins and then necrosis (site of transpiration)
Water - wilting and then nutrient deficiency
What are the impacts of early- versus late-emerging weeds?
Early- occur during the critical period of weed control, impact on yield, bad aesthetics
Late- outside of the critical period, no impact on yield, bad aesthetics
Four factors of growth habit and three of growth rate
Growth Habit
1. Height
2. leaf area
3. degree of branching
4. root architecture
Growth rate (GEAR)
1. genetics
2. environment
3. available resources
What is allelopathy, give three examples
A release of phytotoxins that affect germination rate and growth of the surrounding plants
1 large crabgrass
2 annual bluegrass
3 giant foxtail
Why are seeds able to produce viable seeds in adverse conditions?
Stress in the plant puts the carbohydrates towards seed development. Conditions such as lack of moisture, fertility and temperature, a short growing season, and being cut like with mowing
How does weed seed dormancy influence management?
Dormancy stops the seed from germinating even with optimal conditions. Don’t allow the seed pods to be created. Force the seeds to germ and then control.
because of immature embryo, stratification needed (physiological), and break the seed coat (physical)
Why are vegetative reproductive structures so effective at carrying out these functions?
They have;
1 overwintering structures, bud tissue that is able to overwinter
2 localized dispersal, if they break they can spread by vegetative structures
3 develop faster than seed because of a large storage bank of carbohydrates
Weed seeds can be dispersed by wind, animals, and water. How does this influence their management?
Don’t allow the weed to go to seed. Prevent recruitment sites
Define anemochory, zoochory, hydrochory
Wind dispersed, animal dispersed, water dispersed
Life cycle, method of reproduction and dispersal, growth habit and soil moisture preference of burcucumber and wild cucumber
SA, seed and birds, vining, abundant moisture when establishing
Life cycle, method of reproduction, growth habit of virginia creeper
CP, seeds and rhizome, vining
