Workshop on Herbicide Use Joseph Vitelli DAFF, Biosecurity Queensland, Ecosciences Precinct, Brisbane, Qld, Australia IP&A Sciences

Aimed at solving Queensland's weed and pest animal problems

Integrated weed management tools and practices - aims to develop new, improved, integrated and adaptive management practices for the control of priority weeds, including biological control options for weeds.

Landscape protection and restoration - aims to better understand and manage the processes of pest invasion and landscape restoration to reduce weed impacts and maintain biodiversity and environmental functions in our landscapes. This research program has a strong emphasis on the science behind early incursion response and eradication and the management of environmental and aquatic weeds.

Research Services - delivers analytical and pesticide registration to assist research weed and pest management programs across the state.

AFRS is one of the world's foremost research centres for the biological control of weeds. Invasive plant and animal science units within BQ

Focus on the management of pest plants and animals 3 research locations formerly Alan Fletcher Research Station [AFRS] Tropical Weeds Research Centre Robert Wicks Pest Animal Research Centre IP&A Sciences, TWRC, RWPARC, Dutton Park, Brisbane Charters Towers Inglewood

- 1920 - 1985 - 1983 Biosecurity Queensland - Ecosciences Precinct

Ecosciences Precinct is located in Brisbane ~ 5m from Brisbane's CBD Precinct houses research staff from various Queensland Government Departments, CSIRO and The University of Queensland (UQ) Site accommodates over 1000 scientists Science at the precinct focuses: climate change natural resources and environment primary industries (including grazing, horticulture, grains) forestry fisheries and marine invasive weeds and pest animals Research facilities include laboratories, insect houses, controlled environment rooms, glasshouses, greenhouses, offices, workshops and a science education centre Site contains Level 2 (PC2) laboratories, which is the rating for a standard, low risk research environment Site contains Level 3 (PC3) laboratories, these quarantine facilities enable researchers to conduct secure and carefully controlled studies on insects, and bacteria, fungi and other organisms that may pose a threat to Queensland's environment Biosecurity Queensland - Ecosciences Precinct

• 2 shade houses • 2 PC2 glasshouses • 6 PC3 quarantine labs • 12 glasshouses Weed Basics

What are Weeds? Damage Potential of Weeds Economics of Weed Control Control (Containment vs Eradication) Control options Mecahnical/Physical Burning Livestock Biological Herbicides Key Points from Weed Basics What are Weeds?– definition

• Weeds are plants, which grow where they are undesired and which cause more damage than benefit.

• Natural enemies not present to limit reproduction and spread.

• Native plants can become weeds.

• The consequence of weeds - environmental weeds reduce biodiversity - agricultural weeds reduce yield & profit What are Weeds?– Weedy attributes

Rapid growth Excludes other plants Adaptable to many environments Seed produced throughout season Germination over extended times Seed dormancy Most grass seed are short lived (1 to 4 years) Legumes (hard seeded) may last >20 years Most weed seeds 5 to 50 years Many seeds pass through digestive systems intact eg bird dispersal Defence mechanisms (prickles, spines, thorns repel animals) Invades disturbed areas Root propagation What are Weeds? – compete for limited resources

Weeds compete against the desired plant for limited resources

Water Light

Limited resources

Nutrients Space What are Weeds – grasses and broadleaves

Grasses (Monocots) Broadleaves (Dicots) Damage potential of weeds

• Environment – Reduced biodiversity – Reduced water quality – Land degradation – Soil erosion Damage potential of weeds

Health hazard – Cause allergies Damage potential of weeds

Gamba grass ( Andropogon gayanus ) Social – Fire hazard (fuel load) – aesthetic appeal

gamba grass grows to 4 m tall

producing fuel loads 30 – 40,000 tonnes/ha Damage potential of weeds

Economy – Costs to primary industries • Agriculture • Fisheries – Costs to tourism & recreation – Costs to control Prickly Acacia (Acacia nilotica) – Costs to quarantine

Hymenachne (Hymenachne amplexicaulis)

flora ty and the environment)

Weeds 15% of Australia’a Over $4,000,000,000 (excludes cost to communi NORFOLK I. LORD HOWE Is NEW ZEALAND AUSTRALIA Weed composition 0 70 60 50 40 30 20 10 Environmental weeds

• Species that invade native communities or ecosystems • Undesirable from an ecological perspective • Don’t necessarily have an economic impact • Can modify: • Species richness • Abundance • Ecosystem function • Serious environmental weeds can totally destroy an ecosystem African tulip (Spathodea campanulata) in Tahiti

Greg Calvert Singapore daisy (Sphagneticola trilobata) Leucaena in the Marquesas Islands (Polynesia)

Greg Calvert Greg Calvert Leucaena on Moorea Island (Polynesia)

Greg Calvert Cherry Guava (Psidium cattleianum) Cherry Guava on Norfolk Island

Greg Calvert Rose Apple (Syzygium jambos) Rose Apple (Syzygium jambos)

Greg Calvert Weed Control

• Control a weed only when it is causing or is expected to cause more harm than is reasonable to accept

• Use a control strategy that will reduce the weed numbers to an acceptable level

• Use control options that will best control the weed with minimal damage to the environment Weed Control - identification

• Accurate identification is the first step in an effective weed management program

• Never attempt a weed control program until you are sure what the weed is

• More you know about the weed and factors that influence its development and spread, the easier, more cost-effective and more successful will be your weed control efforts

• Knowledge in the plants basic ecology is critical Time to reproductive maturity Flowering and fruiting period Seed production, seed bank Seed longevity Weed Control – basic ecology

How long do individual plants live? How long does it take young plants to reach reproductive maturity? age at reproductive maturity plant lifespan

How and how far is the seed dispersed?

seed dispersal -wind -water What is the frequency and scale of seedling recruitment? -animal seedling -bird recruitment

How long will it take for the seed bank to be depleted once adult plants are removed from a site? seed bank Weed Control - identification

Samples sent to herbarium both species identified as Cecropia peltata Weed Control - identification

Samples sent to herbarium both species identified as Cecropia peltata Cecropia peltata Pourouma cecropiifolia

Pistillate inflorescences

Staminate inflorescences

Seed Weed control strategies

• Prevention Keeping a weed from becoming a problem

• Eradication Destroying an entire weed population

• Containment Deliberate action taken to prevent establishment and reproduction of a weed species beyond a predefined area

• Suppression Reducing weed numbers to an acceptable level

• Do Nothing Weed control strategies - Prevention

• Normally a goal when the weeds presence or abundance can be predicted in advance • Most cost effective means of managing weeds, is preventing the entry of new weeds • Once weed established, eradication far more expensive, requiring greater resources to control its spread and impact.

Legislation on invasive weeds Quarantine and importation restrictions Restrict the movement of goods, animals and vehicles contaminated with weed seeds Weed control strategies - Eradication • Elimination of every single individual of a species from an area in which recolonization is unlikely to occur

• Many eradication programs may extend to 10 years or more

• Very few examples in the world of successful eradication Weed control strategies - Eradication/Containment/Suppression

• If a weed becomes established, many of the control options are similar irrespective of strategy

• Once initial infestation controlled, follow-up monitoring and control required to ensure reinfestation do not occur Control options - Physical

• Any technique that uproots, buries, cuts, smothers, or burns vegetation

• Removal of weeds by – Mowing (annual weeds, tree saplings, grasses, shrub and vines) – Slashing (annual weeds, tree saplings, grasses, shrub and vines) – Mulching (annual weeds and seedlings) – Cutting (vines, shrubs, tree saplings and trees) – Chaining (trees) – Roller chopper (shrubs and tree saplings), – Tilling (annual weeds, shrubs and tree seedlings) – Solarisation (annual weeds and seedlings) – by hand, hoeing, spading, digging (annual weeds and tree seedlings) Control options - Physical

• Method used often depends on the area of weeds to be managed

• Hand removal – By hand, including hoeing, is a good method for selective removal of weeds without disturbing the surrounding desirable vegetation – Effective when soil moist and friable, enables entire plant to be removed – Very time and labour-intensive and is often only used in small areas – Follow-up required to deplete seed reserve

• Factors determine mechanical method include: • Land use • Physical characteristics of the land, eg hills • Value of the land

• Any item that can move from a weed-infested site to an un-infested site (such as machinery, vehicles, tools and even footwear) is cleaned free of weed seed before moving, to stop the spread of weeds to new areas Control options - Physical

• Mechanical methods include: • Stick-rakes • Front and rear-mounted blade ploughs • Chains • Discs • Roller choppers and grubbers

• In tropics wet season normally January-March

• For best results using mechanical control need to apply June–September

• Soil texture, soil moisture, blade depth and weed density can affects root suckering and seedling regrowth

• Best results when soil is wet enough to allow machinery to work with minimal resistance but dry enough to desiccate the root system blade plough Large Acacia nilotica do not reshoot or regenerate from underground roots cut below soil at >20cm depth blade plough woody weed

soil surface lateral roots

20 cm

blade plough well below laterals Parkinsonia aculeata controlled using blade ellrott plough ploughs with either front or back mounted blades

Front-mounted blade ploughs attached to machinery from backhoes to dozers excavator Chain Pulling

• Chain dragged across dense stands of weeds • Double pull in some cases Mesquite (Prosopis palida)

• Prickly acacia (Acacia nilotica) Prickle acacia Single chain treatment 20% kills Double chain treatment 90% kills Ineffective on seedlings and saplings dozer dozer grubber (tractor with a scoop or grubbing attachment)

Effective for small infestations roller-chopper

-drum filled with water 1 to 2 tonnes -blades welded 30cm apart Effective depends on the height of the cut Timing of applications Species treated slashing Control options – Physical - Slashing

Jatropha gossypiilolia

Bebawi F.F. and Campbell, S.D. (2002). Tropical Grasslands 65_68. Control options – Cultural control

• Involves manipulating farming practices to suppress weed growth and production, while promoting the development of the desired plant

• Encourage the competitiveness of desired species that are more competitive and fast growing • Shifting between grass and broadleaf plants • Irrigation and fertilising of desired species

• Suppresses weed growth by reducing access to available sunlight, nutrients and moisture Control options - Cultural • Hay making, mowing and grazing – Used before weeds produce seeds to restrict the amount of weed seed in an area and reduce the spread of weeds.

• Mulching – covering the ground with a layer of organic material, suppresses or kills weeds by providing a barrier between the weeds and sunlight (grader grass)

• Tilling (the ploughing or cultivation of soil) – By turning the soil over will buries the weed beneath the soil, providing a barrier to the sun, therefore killing the weeds – easily undertaken over a wide area, using agricultural machinery.

• Burning – susceptible weeds killed – can kill surface seeds, if burnt before seed set can prevent further weed spread – can be undertaken over a wide area with minimal human input. Control options - Cultural

parkinsonia, prickly acacia, chinee apple

Control options – Fire

Ground ignition fire •chinee apple 0% vs woody weeds •rubber vine 45% •mesquite 93% high mortality of seedlings (except chinee apple) mature plant mortality varies with species Simplex Sure Fire 2-10 m drop height gelling agent plus petrol

aerial ignition helitorch helitorch ignited globule Hand held burner 92% mortality 60 seconds

10 seconds

83% mortality 76% mortality Hand held burner

Effective at controlling surface seeds Control options – Biological control

• Biological control approach makes use of the invasive plant's naturally occurring enemies (biological control agents – insects or pathogens), to help reduce its impact and achieve sustainable weed control

• Biological control (in the long term) can be cost effective reducing the need for less desirable management practices

• Not all weeds are suitable for biological control

• Developing a biological control project requires a substantial investment, sometimes costing millions of dollars over many years fruit/seed

leaves flowers bark/stem

WANTED roots a suite of insects to attack different plant parts Control options – Biological control Biological control of prickly acacia (Acacia nilotica)

• 5 biological control agents released on prickly acacia Control options – Biological control Biological control of cat’s claw creeper (Dolichandra unguis-cati)

Initiated in 2001 Collaboration with PPRI, South Africa Two agents released Control options – Biological control Adult Biological control of cat’s claw creeper (Dolichandra unguis-cati)

Agent: Leaf-sucking tingid (Carvalhotingis visenda)

Feeds on leaf tissue First released in June 2007 Establishment confirmed

Eggs

Adult

Nymphs Damage

Damage Control options – Biological control Biological control of cat’s claw creeper (Dolichandra unguis-cati)

Agent: Leaf-tying moth (Hypocosmia pyrochroma)

Causes severe defoliation First released December 2007 Control options – Biological control Biological control of cat’s claw creeper (Dolichandra unguis-cati) Agent: Hylaeogena jureceki- a beetle

Leaf-feeding beetle from Argentina & Brazil Adult Causes severe defoliation – both larvae and adults feed on leaves Larva

Released and established in South Africa Adult feeding damage In QLD: Host testing – overall 50 species from 11 families have been tested Pupae – development only possible on cat’s claw creeper Approval for release is imminent

Adult feeding damage Control options – Biological control Biological control of Madeira vine (Anredera cordifolia) Vigorous climber; fleshy heart-shaped leaves; flower spikes with small greenish-cream flowers; copious aerial tubers Smothers and destroys trees and shrubs Declared Class 3 weed

Flowers

Aerial tuber Control options – Biological control Biological control of Madeira vine (Anredera cordifolia)

Agent: Plectonycha correntina

Leaf feeding beetle from South America Tested using 37 related species Adult and larvae both leaf feeders – larval phase most damaging Larvae covered in ‘blanket’ of excrement Adults are long lived (~120 days) First released May 2011 Plectonycha larvae – 33,500 insects released – assessment to confirm establishment in progress

Plectonycha adult and feeding damage Plectonycha larvae Plectonycha adults Control options – Biological control Biocontrol (Plectonycha) insect damage in the field

Passiflora Control options – Biological control Biological control of Siam weed (Chromolaena ordonata??)

Cecidochares connexa – gall fly • tested against 81 species in 4 countries • released & controlling in PNG, Timor C. Wilson Leste, Palau & Indonesia • imported into ESP quarantine in 2012 • tested against 20 spp. in Eupatorieae • some adults developed on Praxelis clematidea

Gall fly damage Control options – Chemical control

• Compounds used to suppress or kill unwanted vegetation • Herbicides are an important tool for weed control in many countries • In some situations herbicides offer the only practical, cost-effective and selective method of managing certain weeds • Important to use the correct product and application rate for control of a particular weed • Common mistakes include incorrect identification of the weed or using inappropriate products • In most cases, weeds must be actively growing to be vulnerable to herbicide treatments Control options – Chemical control

• Although there are a large variety of herbicides available they function in a limited number of ways, known as modes of action • Modes of action determine how the herbicide controls weeds: – by speeding up, stopping or changing the plant's normal growth patterns – by desiccating (drying out) the leaves or stems – by defoliating the plant (making it drop its leaves) Control options – Chemical control

• Herbicides can be classified according to how they are taken up by the plant • Main types are: – Contact - these kill plant tissue at or near the point of contact with the herbicide (they do not spread around the plant) • require even coverage in their application – Systemic - these move through the plant tissues via the plant's circulation system, and can be injected into the plant – Residual - these can be applied to the soil in order to kill weeds by root/shoot uptake • remain active in the ground for a certain length of time, and can control germinating seedlings Control options – Chemical control

• Herbicides also have differing selectivity's, categorised as – broad spectrum (working on a wide variety of plants) – selective (working on a specific range of plants)

• For example some herbicides are effective on grasses, whereas others are more effective on woody weeds and will leave grasses intact Control options – Chemical control

• Label information – important to read and follow the information contained on the herbicide label. This includes: • the signal heading (indicating the product's hazard level) • the trade name • the claims for use • the active constituent • the net contents • directions for use • limitations for use • withholding period • important notes • storage instructions • safety directions and first aid • dangerous goods notification • expiry date • mode of action (type of herbicide) • By law, herbicides can only be used in accordance with the label Control options – Chemical control Read and understand the label before you mix or apply

Trade Name

Active ingredient

Herbicide classification …has the inhibitor of the enzyme acetolactate synthase (ALS) mode of action.

Integrated Weed Management (IWM)

alternate prevention

biological

ecology

chemical fire physical Integrated Weed Management (IWM)

• Is the combining of appropriate weed control tactics into a single plan to reduce weeds and their damage to an acceptable level

• To solve weed problems: – identify the weed, – is control needed, – what controls are available, – evaluate the risks and benefits, – choose a control strategy that will be most effective and cause the least off-target damage, – use each tactic in the strategy correctly, – observe Local, State, and Federal laws Integrated Weed Management (IWM)

• IWM combines Year 1 = Herbicide application – Chemical Year 2 = Mechanical control + fire – Mechanical Year 3 = Herbicide control – Biological Year 4 = Herbicide control + Biocontrol agents + – Fire competitive species – Understanding of the biology of the targeted weed • Including size of the soil seed-bank • Seed longevity • Germination and establishment requirements • Age at first reproduction • Plant life span

• These factors will strongly influence the economics, feasibility, timing and frequency of control Integrated Weed Management (IWM)

• Each weed control method has advantages and disadvantages

• No single tool will control every weed population

• Unlikely that a weed problem will be solved with a one-off treatment of a single treatment

• If various control options are implemented and followed-up effective control can be achieved

• Choice of options will differ depending on the objectives: – Restore biodiversity – Protect specific endangered species – Increase pasture production for livestock – Increase forestry yields Integrated Weed Management (IWM)

• Important factors to consider is the nature of the invaded environment – non-target vegetation

• Virtually any control technique will have potential to off- target damage – Broad-scale mechanical treatment of weeds may damage native species – Herbicides may not be specific – Fire regimes may favour some natives over others

• Objective in weed management is develop and maintain a healthy plant community that is largely resistant to invasion