### plant | tracheophyte:

Weed
* All weeds are flowers
  - have a time of year or a specific climatic condition that they germinate and grow best
* Keep weeds under control by proper mowing and watering and by spot spraying if necessary.
* Many weeds are also good hosts for reniform nematode
  - highly efficient at using available soil water
  - pests because they have become resistant to herbicides
  - can tap into water deep in the soil
  - carry viruses that can be transferred to pepper plants
  - develop resistance to herbicides over time
  - eaten by horses are nitrate accumulators
  - harbor cucurbit diseases
* Many weeds have a narrow window of opportunity for control - with or without herbicides
  - small seeds that germinate primarily within the top two inches of the soil
  - live within the river and on the riverbed
  - occur only on a single island
  - produce a lot of airborne pollen as well as taking valuable nutrients from the soil
  - rely on mechanical disturbance in order to germinate
  - stick to pant legs and other clothing
* Most weeds adapt to survival.
* Most weeds are much more efficient at taking up and using fertilizers than are trees
  - opportunistic, filling in voids in turf caused by diseases and insects
  - plants that are generally considered undesirable by gardeners
  - attract insects
  - can germinate and become established relatively quickly
* Most weeds compete with landscape plants
* Most weeds die as they begin to emerge from the soil
  - quickly if their roots are exposed to the hot sun
  - grow along trails
* Most weeds grow from roots
* Most weeds grow in habitats
  - ranges
  - unhealthy soil
* Most weeds have economic impact
  - european origins
  - negative economic impact
* Most weeds invade gardens
  - landscapes
  - lawns
  - live for years
  - owe their beginning to seed in the soil
* Most weeds produce a huge number of seeds
  - large number of seeds
  - viable seeds
  - provide habitats
  - stay green longer than crops since they are more deep rooted
  - thrive in exposed soils where there is little competition from other plants
* Most weeds use asexual reproduction
* Some weed is used to prepare liquid seaweed extracts.
* Some weeds absorb water
  - actually act as traps for pests
  - affect flavor
* Some weeds also can be a host for diseases or bug populations
  - produce strong flavours in milk when eaten during grazing
* Some weeds are alien plants that aggressively compete with native plants
  - also host plants of silverleaf whitefly
  - capable of both the summer and winter annual lifecycle
  - edible or have medicinal qualities
  - much more difficult to remove and can be removed with selective use of herbicides
  - natural bird and butterfly foods
  - plants that have been brought from other countries
  - poisonous, eg
* Some weeds are toxic to horses
  - livestock
* Some weeds attract bees
  - rodents
  - become seeds
  - can also contaminate the canola seed
* Some weeds can produce hundreds of thousands of seeds from one plant
  - thousands of seeds in a single season
* Some weeds compete with beetroots
  - sunflowers
  - contain fiber
* Some weeds germinate from seeds
  - in early spring while others sprout in summer or fall
* Some weeds grow in cracks
  - crevices
  - rock crevices
  - sidewalk cracks
  - near hollyhocks
  - on floors
* Some weeds harbor animals
  - insect pests and plant disease organisms
* Some weeds have a tight emergence pattern, while others are more prolonged
  - odor
  - relatives
  - shallow roots and are few enough that they can be pulled by hand
  - special dispersal mechanisms, which contributes to their success
  - taproots
  - thorns
* Some weeds have very rapid reproduction cycles, and the window for control is very short
  - shallow roots and others have deep roots
  - impart off-flavors to milk, butter, cheese, and eggs
  - invade areas
* Use mulches to prevent weed germination.
* also act as homes for insects and disease and can make harvesting more difficult
  - are easy to control a few days after emergence
* also can affect insect pests
  - interfere with irrigation and harvest operations
* also compete for soil moisture and nutrients
  - with the grass for needed water and nutrients
  - control erosion and break up soil with their extensive root system
  - decrease air circulation and slow normal drying of the foliage following wet periods
  - harbor insects and diseases, further reducing lettuce yield and quality
  - have a significant social impact
  - host pathogens, viruses, and insects plus disrupt harvesting operations
  - influence turf in other important ways
  - provide the same benefits for the food source plus protection from the predators
* also reduce land values, causing damaging economic impacts to local communities
  - the aesthetic value of plants being grown for sale
  - serve as feed for chickens and pigs
  - show extreme tenacity of life in many other ways
  - vary in their competitive abilities and according to conditions and season
* always become a problem following the rains, and expect some to be pollen producers
  - seem to grow better in any garden than the flowers do
* are a constraint to rice production throughout Bhutan
  - foodsource for birds
  - highly successful component of most Australian ecosystems
* are a major problem in potato production in Florida
  - reservoir for viruses and diseases
  - threat to natural and managed ecosystems
  - problem around buildings and parking lots, along curbs and gutters and in parks
* are a problem in home gardens
  - parks and wilderness areas, rangelands and managed lands, crops, and turf
  - some pastures
  - serious problem in mustard production
  - sign of pasture stress
  - significant pest problem in most soybean fields
  - also a fact of life in chickpea production
  - among the most serious threats to Australia's primary production and natural environment
* are an almost universal companion of rice in the tropics
  - example of plants that grow quickly and competitively
  - another source of water loss from the soil
  - any plant growing in the wrong place at the wrong time
  - bands
  - capable of growing in almost any soil or site
  - coarser, and some are toxic to horses
  - common to all lawngrasses
  - controlled with chemical herbicides
  - difficult to get rid of because most grow quickly and reproduce in large numbers
* are easier to pull when the ground is wet
  - with all their roots if the soil is moist
  - especially difficult to pull in a rather heavy soil after they have attained any size
  - first classified botanically, and then by their life cycles
  - found throughout the world
  - garments
  - generally exotic garden plants gone wild
  - hardy enough that they can grow on the eroded, nutrient-poor soil
  - heavy in some fields, especially woolly cupgrass, waterhemp, and giant ragweed
  - high where corn don t grow
  - highly desirable plants
  - hosts for insects
  - important in irrigation and drainage systems
  - just ordinary plants which are particularly prolific and hardy
  - larger and harder to kill in poor stands of winter wheat
* are located in fields
  - streets
  - merely plants growing in the wrong place
* are more easily identifiable if they have flowered
  - of a problem in unbalanced soil
  - names
  - necessary for fish habitat and alga feed the creatures that feed the fish
  - niche invaders and inhabit a diverse array of habitats
  - of particular concern to farmers
* are often less resistant to wildfire than are native plants
  - virus reservoirs
* are one of the biggest problems in growing strawberries
  - leading threats to conservation of native species
  - most persistent pests plaguing crop producers, land managers, and homeowners
  - opportunistic plants which follow human disturbance and invade whenever they get a chance
  - out-competing native plant species including several endangered taxa
  - plants out of place
* are plants that are growing out of place
  - colonize disturbed land effectively
  - present at the edge and in shallow spots, being reed, grass, and bottom cover type
  - probably the biggest economic pests to sugar cane culture
  - removed manually in large parts of India
  - rescuers, healers, and restorers of natural order
  - sensitive to herbicides at the moment
* are severe competitors for both water and nutrients
  - signs of neglect
  - simply plants growing in the wrong place
  - spontaneous , appearing without being sown or cultivated
  - strong competitors with garden crops for available water, nutrients, and sunlight
  - survivors or invaders of open habitats
* are the bane of fields, craving is the bane of mankind
  - delusion is the bane of mankind
  - hatred is the bane of mankind
  - lust is the bane of mankind
  - earth's bandaids, who quickly move in to cover up any bare soil
  - horticultural equivalent of a zit
  - most common non-injurious foreign matter found in hay
* are the number one biological constraint, followed by blast disease and brown spot
  - pest problem in sports fields, and golf courses
  - only plants that thrive in miserable weather
  - product of selection and adaptation over long and short time scales
  - toughest pests to control organically, because most weeds are very successful plants
  - thick in places
  - treated when populations increase beyond a predetermined level
  - useful, by forcing the cultivator to work to aerate the soil
  - vascular plants
  - very effective competitors for moisture
  - water wasters
* are well-adapted because they are highly diverse in terms of genotype, phenotype and fitness
  - produce excess, highly fit, offspring than can survive
* are, after all, green plants that serve as food sources for many organisms
  - of course, when compared to grass, the plant world's version of the other
* become more abundant after two or more rice crops
* begin to wilt and die within a few minutes after flaming.
* can acquire resistance to herbicides as a result of natural mutations
  - affect peanut quality as well as yield
* can also aggravate some diseases, if growth is dense and rank
  - harbor insects and diseases and contaminate grain
  - have a negative effect on the reputation of businesses
  - host pests and diseases that can spread to cultivated crops
  - infest areas killed by disease or insects
  - pass through the digestive tracks of animals and still grow
  - pull nutrients from the soil
  - substantially reduce yield and quality of established alfalfa
  - threaten the survival of native vegetation
  - attach to vehicles and fall off further down the road
* can be a major problem for asparagus
  - in raisin vineyards, particularly sand burs and puncture vine
  - pain at the best of times, despite their reputed medicinal qualities
  - problem in any lawn, and patches of brown can indicate insect damage and disease
  - temporary residence for insects and stressed plants are an invitation for problems
* can be either a native or a non-native plant
  - broad-leaved or grasses
  - especially harmful to young vines during the establishment years
  - important sources for insects and mites on a year-round basis
  - one of the most limiting parameters in rapeseed production
  - quite a problem as they compete with the grass for space and nutrients
  - become out of control and drastically reduce yields
  - carry many common viruses, which is another good reason to weed regularly or to mulch
* can cause serious health hazards, such as, itching red skin, blisters and hay fever
  - yield loss and harvesting difficulties
  - come in any shape and size and can be any type of plant
  - damage popcorn by using up all of the water and nutrients that the corn needs to survive
  - destroy a flower, But it can be replanted
  - emerge in such numbers that they reduce the alfalfa stand
* can greatly out-compete the trees for nutrients, especially nitrogen
  - reduce mustard yields
* can grow in very dry conditions
  - without fertility
  - harbor other pest problems such as aphids or whiteflies
  - kill a garden and impoverish the soil
* can make a lake unsuitable for swimming and boating
  - silage dangerous even though there is no nitrate in the corn itself
  - mar the color patterns of annual or perennial flower beds
  - negatively affect quality, especially in the case of noxious weeds
  - outgrow soybeans, stealing moisture, sunlight and nutrients, and thus lower yields
* can reduce fruit yields by competing primarily for water and nutrients
  - mango yields by competing primarily for water and nutrients
  - muskmelon yields by competing for light, water and nutrients
  - yields and create harvesting problems
  - safely and naturally return important trace elements back to the soil
  - serve as alternate hosts for pathogens thus increasing pathogen populations
  - spread fire when dry
* cause abandonment of wildland recreation sites and trails
  - health problems for both humans and livestock
  - serious problems
  - the greatest problem in establishing an asparagus bed from crowns
* clog waterways, destroy wildlife habitats and impede farming.
* commonly inhabit such disturbed areas.
* compete for moisture, nutrients, and light
  - precious water
  - sunlight, water, and nutrients and also host pathogens, viruses, and insects
* compete with Michigan crops for water, nutrients, and light
  - a crop for water, nutrients and light
  - agricultural crops for water, nutrients, light and space
  - all desirable plants for water, nutrients and sunlight
  - cranberries for water, nutrients and most importantly light
* compete with crop for nitrogen
  - plants for moisture, nutrients, and light
* compete with crops for soil moisture and decrease yields
  - space, nutrients , water and light
  - cultivated soybeans for moisture, space, and nutrients
  - desired plants for nutrients and water
  - kiwi plants for water and nutrients
  - ornamentals and turfgrass for water, nutrients, and light
  - other plants for nutrients, light, and water
  - our garden plants for light, nutrients and water
  - plants for water, space and nutrients
  - popcorn for nutrients and moisture
  - potato plants for light, water and nutrients
  - seedling vegetables for light, nutrients, water and space
  - soybeans for moisture, nutrients, and sunlight
  - strawberries for essential water and nutrients
* compete with the crop for light, space, nutrients and, particularly, water
  - nutrients, water, and light
  - soil moisture, sunlight, space, and plant nutrients
  - herbs for soil nutrients, water, and light
  - melon crop for light, nutrients, water and physical space
  - strawberry plants for water, nutrients, and sunlight
  - vegetables for nutrients and can harbor insects and disease
  - tomatoes for nutrients, water, and light
  - trees for moisture and nutrients
  - turfgrasses for light, water, soil nutrients and space
  - vegetables for water, nutrients and light
  - wheat for light, nutrients, water and space
* continue to enter the United States as seed contaminants.
* create large economic losses for agriculture in both cropland and rangeland situations
  - the conditions for bushes, bushes create the conditions for trees
* deprive the crops of moisture and nutritive substances from the soil.
* die and decompose using up dissolved oxygen, and causing sulfurous smells and plagues.
* diminish the yield of agriculture crops thus reducing profitability for the farmer.
* dislodge paving stones and mosaics.
* eliminate open ground, which doves require for feeding.
* encourage pests and diseases.
* flourish in most parts of the country from midsummer to late fall.
* frequently invade turf damaged by brown patch.
* furnish a wide range of hues with which to dye wool for the hobbiest.
* gain a foothold more easily in lawns that are poorly maintained.
* generally invade turf when areas are thin and unhealthy
  - pollinate in the late summer and in the fall
  - release their pollen in late summer and fall
* germinate and emerge more rapidly at later planting dates.
* get an additional advantage when grasses are grazed and become less competitive.
* give a lawn diversity, thereby enabling it to combat a number of pest and disease problems
  - off life-giving oxygen
  - best in compacted hard soils
  - between landscape plants
  - either from seed, or they reproduce from their roots
  - everywhere, even through cracks in the concrete of the streets
  - high over uneven ground, and monuments lie where they fall
* grow in every crevice
  - on every acre used for crop and timber production
* growing over ornamental plants interfere with pesticide applications
  - under hot, dry conditions often become more tolerant to herbicides
* harbor insects and compete for nutrients and sunlight
  - serve as hosts for many virus diseases
* harbour aphids and other pests.
* harm public health, crops, livestock, and the land.
* have a few things in common
  - harder time to adapt when management practices are changing
  - place in the ecological mix as long as they are controlled
  - very long memory when it comes to what herbicides do
  - an enormous capacity for seed production
  - bold aggressive plant personalities, each kind with striking, easily recognized features
  - certain mechanisms for easy dispersal of seeds
  - leaves
  - many benefits - it is better to grow weeds than leave soil bare
* have negative economic impact
  - to be kept in check because they are often a food source before the crop matures
* help create a micro-climate that is ideal for development of fungus and bacterial diseases.
* include thistles.
* includes cell membranes
  - cells
  - corpi
  - cytoplasm
  - nuclei
  - plasma membranes
  - sections
  - vacuoles
* increase the cost of maintaining recreational facilities.
  - the open areas that often occur in older depleted stands
  - when the ecological balance is altered
* love poor, under-fertilized soils.
* move in when lawns are vulnerable and sick.
* never die out.
* often appear as a result of poor management
  - are another source of pathogens
  - steal space, sunlight, water and nutrients from vegetable gardens and flower beds
* originate from seeds dropped by birds, other animals, and the wind, and from imported seed.
* pollinate at sunrise and sundown as air currents turn over.
* present in fall and winter help to reduce erosion and to minimize nitrogen leaching.
* produce large numbers of seeds, usually quite small, often lying dormant for many years
* promote energy.
* propagate weeds.
* provide food and shelter for many animals
  - good breeding grounds for insect pests
  - shelter for numerous organisms
  - the perfect environment for rodents and insects to nest and breed
* quickly grow to cover unsightly scars made to the landscape by man or nature.
* reduce air circulation
  - crop production by competing for water, nutrients, and sunlight
* reduce crop yield and quality and compete for necessary resources
  - by competing for resources and reducing food, feed, and fiber quality
* reduce crop yields and increase the cost of producing crops
  - by competing aggressively for space, water, minerals, and light
  - grower profits by competing for sunlight, water and nutrients
  - light, rob nutrients, and serve as reservoirs for numerous insect and disease pests
  - upland rice grain yield and quality
* remain weeds even when in bloom.
* remove soil moisture and make it impossible to prepare a good seedbed.
* require immediate removals
  - soil moisture and nutrients just as do the pecans
* rob any soil's grow power by crowding out the fruit-bearing plants.
* seem to grow whether it's hot, cold, wet or dry.
* serve as a cover crop before planting.
* shade asparagus, compete for water and nutrients, and reduce yields
  - the bales and can cause snow drifts
* shade the ground preventing the over-heating of soil organisms
  - surface, making it slightly cooler, moister
* spread in different ways
  - seeds to other gardens
  - their seeds in many different ways
  - where flowers of all sorts once grew
* steal light and space by shading lower-growing or less competitive plants.
* suffer when trying to grow under tall and thick turf.
* survive by strangling other plants and taking over their food supply.
* take a lot of water out of the ground, which starve the grass.
* tend to thrive at the expense of the more refined edible or ornamental plants.
* too cause health problems for plants.
* use nutrients and moisture and cause reduced carrot yields
  - intended for phytoplankton
  - water that is otherwise available for more desirable plants
* usually become established and advance along highways, roads, trails, and river corridors
  - get into irrigation water by growing around or on irrigation ditch banks
  - grow faster than good grass and typically come from weed seed in the soil
  - pollinate in late summer and early fall
  - require relatively higher soil fertility than native species
* vary in susceptibility to herbicides.