Weed Management Flashcards
(34 cards)
Weeds have the ability to…
invade, dominate and persist
What are the seed characteristics?
- Longevity of seeds(seed banks)
- Germination requirements filled in many environments
Vegetative Characteristics?
- Rapid growth(vegetative-flowering)
- Perennials with vigorous vegetative reproduction
- Perrenials not pulled from ground easily
- Competitive abilities(climbing, shade, drought, salt tolerant)
Reproductive Characteristics?
- Continuous seed production
- Cross pollination
- very high seed output
- adaptation for seed dispersal(wind, water, animals, machinary)
What parts of agriculture do weeds impact?
- crops
- livestock
- general farming
- rural population
Weed impacts on crops?
- yield reduction
- loss of yield
- reduced quality
- crop refusal
- increased transportation & production costs
- weed seeds/plant material cause heating in storage
- low tolerance for weed seeds(eliminate crop as certified seed source)
Weed impacts in livestock?
- reduced grazing area
- reduced forage production/quality
- effects milk/meat quality
- health issues
Weed impacts on general farming?
- Increased sanitation needs
- reduced ability to work soil
- limit management choices
- harbor other pests(diseases & insects can overwinter on vegetation)
- interfere with harvesting
Weed impacts on rural population?
- Use/spray drift concerns
- human health concerns
- drainage issues
- visibility at road crossings
- overall cost
What makes weeds successful? How?
Ability to interfere with growth of desirable plants
- Allelopathy
- Competition
- Parasitism
What are allelopathy plants?
Have the ability to release toxins in their root zone that interferes with the growth of other plants(rye)
what makes weeds competitive?
-based on timing of weed emergence (1st plant has the advantage) -weed density -growth habitat and rate -sexual reproduction -seed banks
In what 2 ways can weeds spread?
Artificial and natural agents
How do weeds spread by artificial agents?
- contamination seed/soil
- transport systems
- moving equipment
- clothes/belongings
- irrigation water
How do weeds spread by natural agents?
- wind/water
- animals, rodents, birds
- reproduces using vegetative structures
- allow for overwintering
- propagation
- extend parent plant to new sites
- grow faster than those from seed
- aid in survival after distribution
Types of weed distribution?
- patches
- outer field edges
- widespread, even distribution
- populations dependent on topography
Weed control/prevention of spread?
- use certified, weed-free seed
- prevent seed set
- practice roadside/fence line sanitation
- prevent spread
- avoid contamination feed/soil
- establish competitive crops
- integrate weed management
- avoid build-up of resistance
- ensure tillage operations aren’t spreading
- ensure tillage operations aren’t spreading the problem
Weed resistance?
- Multiple resistance wild oat and kochia are the top HR weed problems
- consistent applications of BMPs is the best long-term strategy
Top 5 weeds in MB?
- |Green foxtail
- wild buckwheat
- barnyard grass
- wild oat
- volunteer conola
What a summer annual?
1 growing season, fast growing with high seed return, seeds dormant over winter(Lambs quarters, green foxtail, redroot pigweed)
Possible Reduction- Less tillage
What a summer annual?
1 growing season, fast growing with high seed return, seeds dormant over winter(Lambs quarters, green foxtail, redroot pigweed)
Possible Reduction- Less tillage
What’s a winter annual?
Germinate late summer/fall, dorment winter, flowers in spring, sets seed and dies before summer heat(cleavers, shepherds purse, chickweed)
Possible Reduction-easiest to kill in fall before hardened or first thing spring
What’s a biennial?
Lives 2 years(Year 1-Vegetative, Year 2-Reproductive) Commonly found in reduced tillage sites and perennial forages(common burdock, white cockle)
Possible Reduction-spot spray, plant something to choke them out
What’s a perennial?
Grows many years, vary widely in how they spread, difficult to control, extremely competitive in annual crops often found in perennial forages
Reduction-fall systemic herbicide application for long-term control( moves through plant)
