What happens in a minute?

Answer 1

Sixty seconds pass every minute. Everytime a minute passes, 1/60 of an hour passes. If you waste one minute doing nothing, then you wasted one minute of your life. Also, a lot of historical things can happen in one minute.

In about 60 of these you will have read this! LOL

[Editor's Note: Mohamed M. Radwan, Mahmoud A. ElSohly, et al., researchers at the University of Mississippi, reported the discovery of nine new cannabinoids in their Apr. 3, 2009 study titled "Biologically Active Cannabinoids from High-Potency Cannabis Sativa," published in the Journal of Natural Products. This discovery brings the total number of cannabinoids to about 80, according to an Apr. 12, 2009 bulletin published by the International Association for Cannabis as Medicine.]

Weed preventionPrevention is the most effective method of dealing with weeds. Once a weed has entered an area and become established, eradication is far more expensive and it is likely that greater resources will be required to control its further spread and reduce its impact.

The first step in weed prevention, and the most cost effective means of managing weeds, is preventing the entry of new weeds into Australia.

Once a weed has entered Australia, early detection and eradication is crucial to reduce its potential environmental and economic impacts. It is much easier to treat weeds when present in small numbers than when they are well established.

Early detection and eradication requires an awareness and understanding of the factors that favour the establishment and spread of weeds, and applying appropriate management practices that can prevent or reduce the risks.

The importance of weed spread prevention has grown with the recognition that the spread of most weeds occurs through similar pathways, such as the movement of goods, animals and vehicles contaminated with weed seeds. Currently, individual states and territories have different approaches to managing the spread of weeds.

Weed prevention in agricultureIn agriculture, the pathways for spread include transported livestock and fodder, contaminated crop and pasture seeds, deliberate introductions of new species, and contaminated machinery such as harvesters and recreational vehicles (including boats which can spread water weeds).

There are many ways to prevent weeds in agricultural activities which are well known including:

Restricting the opportunity for new weeds to invade and spread:

• Be vigilant about introducing stock, fodder or seed onto your property to ensure weeds will not be introduced.
• When buying stock, find out where the stock has come from and what weeds infest that area.

  Buy certified weed free fodder and seed where possible.

• Restrict the movement of vehicles and machinery on your property in periods when seeds are likely to spread.
• Establish tracks and laneways along which vehicle movement can be concentrated.
• Wash down vehicles which have been in known infested areas.
• Do not allow machinery or vehicles to enter your property unless they are clean.

Restricting the spread of existing weed infestations:

• Carry out control works prior to other works.
• Slash and cultivate when weeds are outside of seeding period.
• Work the clean area first and the infested area last. Work from the outside in and clean down equipment prior to moving into a clean area.

Quarantine:

• Hold livestock that may be infested with seed in a single location until they are shorn or until weed seeds have had the chance to pass through their digestive system.
• Feed out infested fodder in a feed lot type situation only and introduce clean fodder to stock.

Monitor:

• Continually monitor weed infestations and carry out control works.

Weed prevention in your backyardPlants from commercial nurseries, landscaping suppliers and gardening clubs can also be pathways for the introduction and spread of weeds. Another significant cause of weed spread is inappropriate use and disposal of garden waste.

There are a large number of potential weeds in Australian gardens. Private gardens contain over 4000 plant species with weed potential, while botanic gardens hold approximately 5000 species of plants with weed potential. The likelihood that any particular plant will become a weed is difficult to predict; however, the CSIRO has estimated that an average of 10 weed species establish in Australia each year.

Measures for weed prevention in your backyard include:

• Choose plants that are unlikely to become weeds in your area.
• Check existing garden plants are safe.
• Remove potentially weedy plants.
• Dispose of garden waste carefully.
• Be careful not to spread weeds.
• Place mulch on soil surfaces in the garden to reduce weeds growth.

Weed prevention in the natural environmentLandscapes that contain a diversity of healthy, vigorous vegetation with very little bare ground have the ability, in most cases, to deter weed invasion. It is important to reduce the risk of the environment becoming vulnerable to invasion by exotic species by encouraging beneficial vegetation growth and by avoiding disturbance as much as possible.

Measures for weed prevention in the landscape include:

• Minimise the disturbance of desirable plants along trails, roads, and waterways.
• Maintain desired plant communities through good management.
• Monitor high-risk areas such as transportation corridors and bare ground.
• Revegetate disturbed sites with desired plants.

Weed Spread Prevention Action Plan

Weed Spread Tools

Pathway Risk Analysis for Weed Spread within Australia

Reference Database

Weed Spread Prevention Action Plan

The Strategic Analysis and Scoping Study on Human Spread of Weeds project was funded through the National Heritage Trust 2003-06 National Weeds Program. The Australian Weeds Committee endorsed the project and selected members to the project steering committee.

The intent of this project was to determine through consultation with government, industry and other organisations what activities were effective in minimising (or preventing) weed spread.

The major findings of the study were:

• Government, industry and other organisations are committed to preventing weed spread.
• The lack of objective measures made evaluating existing tools difficult.
• No one tool was seen as effective across Australia and only a few tools were identified at the State/Territory level.
• Participants found it difficult to determine if the effectiveness of tools was genuinely low or whether it was low because of a lack of resources to adequately implement use.
• The most common solution given was to have a consistent approach to weed spread management across all States and Territories and at all levels of government - this was closely followed by developing and maintaining a capacity to detect and eradicate new infestations.

A copy of the report is available from the following links:

• Strategic Analysis and Scoping Study on Human Spread of Weeds - part 1 (pdf 92kb)
• Strategic Analysis and Scoping Study on Human Spread of Weeds - part 2 (pdf 214kb)
• Strategic Analysis and Scoping Study on Human Spread of Weeds - part 3 (pdf 246kb)
• Strategic Analysis and Scoping Study on Human Spread of Weeds - part 4 (pdf 809kb)

Weed Spread Tools

A national list of codes of practice and tools aimed at reducing weed spread is available for down load in PDF format according to spread pathways listed below. They contain links to web sites that may be broken due to external organisations web site changes. Therefore we suggest using a key word search on the relevant site. Movement of Contaminated Products and Materials (pdf 26kb)

Movement of Contaminated Vehicles (pdf 26kb)

Other Tools (pdf 40kb)

Pathway Risk Analysis for Weed Spread within Australia

There has been considerable effort to understand the means by which weeds and potential weeds enter Australia (e.g. Groves 1997) and to assess the risks associated with the importation of plants (Groves et al. 2001). However, no comprehensive studies have been undertaken to ascertain the ways that weeds spread once present within Australia, or to assess the relative threats or risks (likelihood and potential magnitude) of different weed 'sources' and 'pathways' due to species, quantity of propagules, distance, and sensitivity of the invaded environment.

The overall goals of this project were to:

1. assess the relative risks of the different sources and pathways of weed ingress within Australia, and
2. identify ways to reduce these risks.

The first stage of the project involved a review of Australian and International literature on weed spread. The review identified twenty four weed sources (sites or areas of land where weeds are actively growing and from which new invasions may emerge) and 17 weed pathways (the means by which weed propagules are moved). The 17 pathways were grouped according to: deliberate spread by humans, accidental spread by humans, and natural spread. The effectiveness of management approaches to halt weed movement were evaluated.

Many individuals and organisations, including research and extension agencies, have first-hand experience in the form (levels) and function (principles) of weed spread. The second stage of this project involved collating the experience of these individuals and organisations with respect to each of the weed sources and pathways identified in the review of literature, to build a major repository of information regarding the relative risks of weed sources and spread pathways in Australia.

Australian scientific weed experts were identified and surveyed by questionnaire to provide their experience of relative risks of weed ingress, the effects of changing trade patterns and environmental conditions, and effective management techniques. Over 100 responses to the survey were received.

This project was conducted by Professor Brian Sindel, School of Environmental and Rural Science, University of New England, with the assistance of the Institute for Rural Futures.

The project was funded by the Defeating the Weed Menace R & D Program, managed by Land & Water Australia on behalf of the Australian Government Department of Agriculture, Fisheries and Forestry and the Department of the Environment, Water, Heritage and the Arts. The link below takes you to the University of New England Institute for Rural Futures Weed Spread page which details the above: www.ruralfutures.une.edu.au/projects/3.php?nav=Change%20in%20Rural%20Industries%20and%20Communities&page=109

Reference Database

A reference data base of weed spread related documents containing 231 records has been compiled and can be downloaded in an Excel spreadsheet from the link below. Weed Spread Reference Database

Note: that the spreadsheet is in Excel 2007 format and uses the table function which enables easy sorting of records based on criteria in any column.

Photo Gallery

Alligator weed has hollow stems when mature. Photo: M. Kahler

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Other publicationsTitlehttp://wiki.answers.com/alligator/suppression-of-alligator-weed-in-pastureshttp://wiki.answers.com/alligator/alligator-weed-control-manualhttp://wiki.answers.com/alligator/early-detection-guide-for-farmershttp://wiki.answers.com/alligator/alligator-weed-idhttp://wiki.answers.com/alligator/alligator-weed-wmghttp://wiki.answers.com/alligator/alligator-weed-strategyStatus

• Declared in NSW under the Noxious Weeds Act 1993 (Current Status)

• Weed of National Significance (definition)

• Water Weed (definition)

Contacts and Further InformationIf you find this weed please help to prevent its further spread by contacting your local Council Weeds Officer or the nearest Industry and Investment NSW office immediately for positive identification and further assistance.

Alternatively call the NSW Weeds Hotline on

1800 680 244 or send an email to weeds@industry.nsw.gov.au

Download PDF version 685kb

Alligator weed (Alternanthera philoxeroides)Answers.com| Answers.com| Answers.com| Answers.com| Answers.com| Answers.com

Alligator weed (Alternanthera philoxeroides) is a potentially devastating weed that grows in water and on land, affecting both waterways and floodplain areas. It is listed as a Weed of National Significance (WoNS).

It is a native of South America and a major problem in south-eastern United States, China, New Zealand, Burma, Thailand, Indonesia and India. Alligator weed has not reached its potential distribution in Australia or within NSW, but has the ability to devastate the environment and agriculture if left unchecked.

Alligator weed has extremely vigorous growth and great tolerance of normal control measures, which makes it a major threat to wetlands, rivers and irrigation systems. It is declared a noxious weed throughout NSW and is one of the highest priority weeds for detection and management in NSW.

DistributionAlligator weed is a native plant of the Parana River floodplains in northern Argentina and adjacent countries. It was possibly introduced into Australia in the Newcastle area via cargo from ships during the Second World War. Since its introduction alligator weed has spread to nearby seasonally flooded agricultural and grazing lands of Fullerton Cove, Williamtown and the Raymond Terrace area, and has steadily expanded to infest many creeks, lowlands and drainage channels in the lower Hunter region. It was recorded in a dam at Woomargama near Albury in 1967, and after its first recording in the Sydney basin at Duck Creek in 1969 it spread within the Parramatta catchment and throughout the Georges River catchment. In 1981 it was recorded at Camden and new infestations were then reported throughout the 1990s, with alligator weed found higher in the Hunter catchment in the Williams and Paterson Rivers in 1993; in Barren Box Swamp near Griffith in 1994; and in Byron Creek, a tributary of the Richmond River on the far north coast in 1998.

In 1995 alligator weed was observed in a backyard vegetable garden in Brisbane, grown as a substitute for the herb and vegetable Mukunawanna (Alternanthera sessilis), favoured by Sri Lankans. Investigations during the following years found it growing in many NSW backyards. More than 500 infestations have been found in the Sydney metropolitan area, and numerous infestations have been reported in many regional areas across NSW.

There is now an estimated total area of 3,950 ha of known alligator weed in NSW, with 2,500 ha of terrestrial infestations and 500 ha of aquatic infestations occurring in the Lower Hunter region. The current distribution is small when compared to the potential range of the weed.

HabitatAlligator weed will grow in ponded and flowing waterways, on the banks of waterways, on floodplains and poorly drained land, and less commonly in drier situations above flood level. To date in Australia all infestations have occurred in temperate and subtropical climates, thriving in areas with high summer rainfall. Alligator weed will grow in a range of soils and substrates from sand to heavy clay, and can easily tolerate dry periods. Infestations have been found growing in saline conditions (flowing water with 30% of the salinity of seawater), and on beaches above the high tide zone. Frost and ice kill exposed stems and leaves, but protected stems can survive these conditions and support the next season's growth. ImpactAlligator weed is considered one of the world's worst weeds because it impacts on both aquatic and terrestrial environments. Overseas experience indicates that its potential impacts in Australia could be devastating. Environmental impactsAlligator weed disrupts the aquatic environment by blanketing the surface and impeding the penetration of light. Such blanketing can also impede gaseous exchange (sometimes leading to anaerobic conditions) which adversely affects aquatic flora and fauna. It also competes with and displaces native flora along river and creek banks and in wetlands. Impacts on primary production

Alligator weed has eliminated small crops and turf farming from parts of the Lower Hunter. The potential costs to irrigation farming in the MIA from the Barren Box Swamp infestation have been estimated to be $250 million a year if alligator weed remained uncontrolled.

In the Sydney Basin alligator weed is currently threatening the turf industry valued at over $50 million annually. The vegetable industry valued at $150 million annually is also under threat in the Hawkesbury-Nepean catchment. The extraction industry in the Hawkesbury-Nepean is also under threat. This industry supplies most of Sydney's sand, gravel and soil resources. If contaminated, the movement of these resources would be severely restricted. Sugar cane and soy bean industries are also threatened in the Richmond catchment.

Alligator weed contaminates grazing pastures and competes successfully for light and space, becoming dominant in wetter sections of pastures. Dense infestations also restrict stock access to drinking water.

In New Zealand and Australia, alligator weed is thought to cause photosensitisation in light-pigmented cattle, resulting in cancerous lesions.

Impacts on water resources and infrastructureAlligator weed restricts access to and use of water, blocking and damaging pumps and other infrastructure. Mats of alligator weed can impede stream flow and lodge against structures promoting sedimentation which contributes to flooding and structural damage. It is currently threatening Warragamba Dam, Sydney's major water supply and storage system. Social impacts

Tourism and recreation are affected when alligator weed limits recreational activities, reduces aesthetic values, and increases mosquito populations. Dense mats reduce the visual impact of waterways and affect the presence of other native flora and fauna. They also limit water vessel movement and access to waterways, and create a hazard for swimming and other water sports.

During 2008/2009, alligator weed cost state and local government authorities in NSW $800,000 to control. When considering other associated costs of education and awareness programs as well as planning, coordination and inspection, the total expenses would be approximately $1,300,000.

Overseas

Alligator weed is a problem in 30 countries. It is a serious weed in eight of these and a major weed in the others. In the USA floating alligator weed caused major impediments to navigation on the Mississippi River. In North Carolina aquatic infestations increased from 152 ha in 1963 to 1000 ha in 1999 along with a conservative estimate of 4000 ha of infested cropping land. It is a major weed of transplanted rice wherever it is grown in the world. In China crop production is reduced between 20 to 63%. It impacts on hydro electric power production, fishing and has seriously degraded famous scenic spots.

DescriptionAlligator weed is a summer growing perennial herb (see Figure 5). It has small white papery flower heads 8-10 mm in diameter, generally appearing from November to March. The flowers grow at the end of short stalks which rise from the leaf axils.

Alligator weed has leaves occurring in opposite pairs along the stems. The leaves are shiny, spear-shaped, sessile (no stalk), entire and about 2-7 cm long and 1-2 cm wide.

The plant forms dense mats of interwoven creeping and layering stems. Over water, stems grow to 60 cm high and up to 10 m long and have large, hollow internodes. Mats may extend 15 metres over the water surface and become so robust they can support the weight of a person. On land, stems are shorter and internodes are smaller and less hollow.

Alligator weed has an extensive underground root system. Roots are relatively fine and short in water but become thicker, starchy and rhizome-like in soil, able to penetrate to depths of over 50 cm. Roots and stems have been found growing more than 1 m below the surface. Root storage tissues allow for survival over long dry periods.

Key identification features

Alligator weed is generally distinguished from other plants by its combination of the following three features:

• small white papery flowers on short stalks
• leaves in opposite pairs
• hollow stems.

Life cycleAlligator weed does not produce viable seed in Australia. Reproduction is entirely vegetative with new plants able to occur at any stem or root node. Stems break up naturally or with disturbance, creating many fragments capable of forming new plants.

A warm growing season is preferred and generally occurs between November and May, with maximum growth and reproduction from stem nodes in mid-summer. Growth generally slows or ceases during cooler months.

SpreadAlligator weed spreads naturally in water when stem or root fragments float downstream. The most significant spread between catchments in NSW has been through the commercial and recreational activities of people. Examples of these activities include:

• excavation machinery used to clean channels
• boats and trailers transported between waterbodies
• deliberate planting for ornamental use
• movement of sand dredged from infested catchments.

In terrestrial situations stem and root fragments can be spread in the movement of soil. This has occurred as a result of:

• movement of turf or hay from infested farms
• movement of fill or landscape supplies from infested areas
• accidental spread on machinery
• fragments caught in horses' hooves.

Control and managementThe Alligator Weed Control Manual provides a comprehensive overview of the various chemical, physical and biological control options. Management options for alligator weed depend on the site and location of the infestation, its age and extent and the resources available. Any new infestation should be assessed to determine if immediate eradication is a feasible management objective (small numbers of scattered plants; infestations up to 5 m x 5 m). If not, management should aim for suppression leading to eradication over a period of approximately 6 years (infestations with roots more than 1 m deep; areas of infestation over 10 m x 10 m), or ongoing suppression (in extensive, long established infestations).

Control methods and their application will vary depending on the management aim. While containment and prevention of spread will be necessary in all infestations, controls should be closely aligned with management aims. Table 1 provides a guide for selecting appropriate control methods for the situation. Table 1. Guide for selecting control methods.Management aim

Control strategy

Immediate eradication

Physical control (deep manual digging) with some initial chemical control (herbicide treatment) to kill above-ground plant growth.

Suppression leading to eradication

Chemical control (annual treatment program, see below) with herbicides over a 6 year period; possibly with initial physical control (shallow mechanical removal to remove above-ground biomass); followed by physical control (deep manual digging) once infestation is small enough to eradicate.

Ongoing suppression

Chemical control (annual treatment program); or biological control (only in aquatic situations in cool climate areas).

Chemical controlDue to its ability to tolerate most herbicides, many herbicides have been trialled over the years for alligator weed control. It is now clear that there are important roles for specific herbicides in suppressing and depleting alligator weed and in assisting with eradication.

It is currently agreed that a program based on three treatments of herbicide products containing metsulfuron-methyl per growing season is the most effective for suppression of both aquatic and terrestrial alligator weed. For application rates and concentrations in aquatic and terrestrial situations please refer to the current range of permits and label registrations for the use of herbicide products containing metsulfuron-methyl 600 g/kg on alligator weed in NSW. These are listed in the NSW DPI Noxious and Environmental Weed Control Handbook (available at any office of Industry & Investment NSW (formerly NSW DPI) office, or on the Australian Pesticide and Veterinary Medicines Authority website (www.apvma.gov.au).

Metsulfuron-methyl Annual Treatment Program

1. Apply the first foliar treatment in November (early in the growing season - could be earlier in subtropical areas).
2. Apply the second foliar treatment in February.
3. Apply the third foliar treatment at the end of the growing season in May.

Carry out this annual treatment program for a number of years (6 on average) and then consider the possibility of eradication by physical removal of any remaining underground plant parts.

Note: Make the second and third treatments only if there has been sufficient regrowth (at least 5 or 6 sets of leaves on stems, 10 cm of stem length, or 30 cm crown width in prostrate growth). In dry conditions the plant may be suppressed and depleted to the point where only 2 applications are possible over the growing season. This can also occur after 2 consecutive years of treatment, as the depleted plants take longer to reach the required level of regrowth. Always maintain at least 2 sprays per growing season.

Physical control

Physical controls are vital for the eradication of small and isolated infestations and are particularly useful in removing new infestations if they can be located early enough.

For alligator weed, physical control involves either deep manual digging or shallow mechanical excavation. Deep manual digging can be done in terrestrial and shallow aquatic situations and requires an infested area to be hand dug in order to find and remove all the roots associated with each individual stem arising from the ground. While time-consuming, local weed authorities have shown this technique to be successful for eradication of small or new infestations.

Shallow mechanical removal can be used to remove large amounts of above-ground plant material and small amounts of below-ground root material. Excavations should only be made to a depth of 20 cm due to the sheer volume of contaminated soil to be disposed of. An excavated site is then inspected regularly for signs of regrowth, which are then either treated with herbicide or removed by deep manual digging, depending on the management aim. Shallow mechanical removal is generally not appropriate in aquatic situations and the risks of spreading fragments are high.

DisposalWith any physical removal method there are issues of disposing of the removed plant material. Removed material must be treated and disposed of securely.

Do not dispose of alligator weed in green waste or composting facilities.

Plant material can be dried and incinerated, boiled or microwaved. Large volumes of contaminated soil are difficult to process, and if possible need to be spread on an impenetrable surface and dried prior to burial (preferably sealed in containers) at a secure disposal site that can be monitored for any signs of regrowth.

Councils and landowners require a permit from Industry & Investment NSW to remove and transport alligator weed.

Machinery hygieneAccidental spread on machinery can introduce the plant to new areas with disastrous consequences. Any machinery working in an infested area should be thoroughly cleaned before it is moved to a new site. Cleaning should include removal of all mud and vegetation, followed by complete and thorough inspection of the machine.

Once alligator weed is established on land it cannot be controlled by cultivation or slashing. Any cultivation or slashing of infested land will only spread the infestation further.

Biological controlThe flea beetle (Agasicles hygrophila) was first introduced to Australia in 1976. It provides good control in aquatic environments in the Sydney region, successfully reducing the area of floating mats in the Georges River and in parts of the Hawkesbury Nepean system. However, this insect is limited to warm temperate and subtropical areas and the predicted range for alligator weed in Australia far exceeds the predicted range for the flea beetle.

One criticism of the flea beetle is the tendency for alligator weed to fragment when under attack, causing downstream spread. Plant fragments should be contained if downstream spread is an issue in areas where the flea beetles are active.

A moth Arcola malloi contributes to control in aquatic habitats and is established but, like the flea beetle, has no impact on terrestrial alligator weed.

The role of these agents is therefore limited to ongoing suppression of extensive aquatic infestations. Biological control is not appropriate for eradication strategies. Further biological control programs are being explored.

LegislationAlligator weed is declared a Class 2 or 3 noxious weed throughout NSW. Under the NSW Noxious Weeds Act 1993, the presence of a Class 2 weed must be notified to the Local Control Authority and the weed must be fully and continuously suppressed and destroyed. In areas where there are dense infestations of alligator weed regional management plans outline the appropriate actions to be undertaken. For new incursions of alligator weed, initial treatments may be undertaken by the Local Control Authority. Follow up works will then be the responsibility of the owner or occupier of the land, who must take effective measures towards eradication. Failure to do so could result in legal action and a fine. AcknowledgmentsTechnical reviewers: Melissa Freeman, Peter Gorham, Mark Scott and Birgitte Verbeek.

Production coordinated by Elissa van Oosterhout.

ReferencesThe information for this Primefact was taken from the following sources.

• Agfact P7.6.46 Alligator weed.
• Alligator weed control manual: Eradication and suppression of alligator weed in Australia, 2008, NSW DPI, Orange.
• Gunasekera, L. and Rajapakse, H. 1998. Alligator Weed - a potential ecological disaster lurking in Australian backyards. Proceedings of the 10th EWRS Symposium on Aquatic Weeds.
• Julien, M.H. 1995. Alternanthera philoxeroides (Mart.) Griseb. In (Eds) R.H. Groves, R.C.H. Shepherd and R.G. Richardson, The Biology of Australian Weeds, Volume 1.
• Julien, M.H. and Stanley, J.N. 1999. The management of alligator weed. Proceedings of the 10th Biennial Noxious Weeds Conference, Ballina July 20-22 1999, pp 2-13.
• Sainty, G., McCorkelle, G. and Julien, M.H. 1998. Control and Spread of alligator weed, Alternanthera philoxeroides, in Australia: lessons for other regions. Wetlands Ecology Management, 5: 195-201.

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