Pyresta

Pyresta

1 Trade name	Manufacturer	Form	APVMA
PYRESTA LV HERBICIDE	SIPCAM PACIFIC AUSTRALIA PTY LTD	EC	61328

2 PRICE:$19.25

3 ACTIVE INGREDIENTS:2,4-D LV ester 421g/L + Pyraflufen-ethyl 2g/L

4 CHEMICAL GROUP: I,G Disrupters of plant cell growth

5 RELATED HERBICIDES:

Group I Herbicides2,4-D amine 500	2,4-D Amine 500g/L
2,4-D amine 625	2,4-D Amine 625g/L
2,4-D amine plus Dicamba	2,4-D 250gL + dicamba 100g/L
2,4-D ester 800	2,4-D Ester 800g/L
2,4-D ester plus Garlon	2,4-D ester 530g/L + triclopyr 200g/L
2,4-D LV ester 600	2,4-D LV ester 600-680g/L
2,4-DB 400	2,4-DB 400g/L
2,4-DB plus MCPA	2,4-DB 200g/L + MCPA 250g/L
Access	Picloram 120g/L + triclopyr 240g/L
Dicamba 200	Dicamba 200
Dicamba 25 plus MCPA 150	Dicamba 25g/L + MCPA 150g/L
Dicamba 500	Dicamba 500g/L
Dicamba 700	Dicamba 700g/kg
Dicamba plus MCPA	Dicamba 80g/L + MCPA 340g/L
Garlon 600	Triclopyr 600g/L
Grazon Extra	Aminopyralid 8g/L+picloram 100g/L+tricolpyr 300g/L
Hotshot	Aminopyralid salt 10g/L + fluroxypyr-meptyl 140g/L
Lontrel	Clopyralid 300g/L
Lontrel 750	Clopyralid 750g/kg
MCPA amine	MCPA 500-750g/L
MCPA LVE	MCPA LV ester 500g/L
MCPB 400	MCPB 400g/L
Picloram plus Triclopyr	Picloram 100g/L + triclopyr 300g/L
Starane 200	Fluroxypyr 200-400g/L
Tordon 242	MCPA 420g/L + picloram 26g/L
Tordon 75-D	2,4-D 300g/L + picloram 75g/L
Tordon DS	Picloram amine 100g/L + triclopyr amine 200g/L
Tri-kombi	24D Ester 800g/L + Dicmaba 40g/L + Mecoprop 336g/L

Group G HerbicidesAffinity	Carfentrazone-ethyl 400g/kg
Blazer	Acifluorfen 224g/L
Flumioxazin	Flumioxazin 500g/kg
Goal	Oxyfluorfen 240g/L
Hammer	Carfentrazone-ethyl 240g/L

6 GENERAL DESCRIPTION:

Pyresta is a mixture of two active ingredients. The 2,4-D is a selective, translocated, foliar absorbed, post emergence herbicide that controls a large range of broadleaf weeds.
The pyraflufen component is a rapidly absorbed, fast acting, contact, non residual, post emergent herbicide for the control of broad leaved weeds and has action on some grasses.
In Australia it is usually mixed with glyphosate as a pre planting herbicide.

7 APPLICATION METHODS AND TIPS:

Best results on young actively growing plants in moist soil in fine weather.
Some species (e.g. cotton, vines, tomatoes, lettuce) are sensitive to very low rates and drift may cause damage.
Apply in 30-100 L/ha water for boom spraying. Use higher water volumes on small weeds and in dense infestations.
Ensure good coverage.
Regulations require the use of coarse spray droplets when applying 2,4-D. Keep droplet density greater than 30/cm².

8 WEATHER:

Rainfast in 3-4 hours. The label quotes 6 hours because it is normally applied with glyphosate.
Frost effects: Frost before application may retard weed growth thus reducing translocation. For best results, 2-3 frost free days are required after application.
Wind: Regulations require application when wind speeds are between 3 and 15 km/hour to reduce the risk of damage caused by drift. Avoid spraying when wind is blowing towards sensitive crops.
Inversions: Don't apply during inversion conditions as damaging levels of herbicide drift may move a kilometre or more.
Temperature:
Delta T and Relative Humidity: Avoid application when Delta T is greater than

9 ADJUVANTS:

Adjuvants are not normally required. A non ionic wetting agent may be useful on hard to wet weeds.

10 WATER QUALITY:

Hard water: Very hard water can cause the product to separate from the water.
Salty water: Can cause the product to separate from the water.
Colloids: Little effect.
pH:
Tank life:

11 COMPATIBILITY:

Trace elements: generally not compatible.
Ester formulations generally have good compatibility providing the emulsifier is not overloaded and the product separates from the water (do a jar test).
See HerbiGuide Compatibilities button.

12 EQUIPMENT:

Boom sprays:
Carrier volume: 60-150 L/ha water recommended on label. Use finer nozzles or faster speeds if using carrier volumes down to 30 L/ha and ensure that droplet density is more than 30 droplets/cm², especially if small weeds are present.
Regulations require the use of coarse droplets (ASAE S572) to reduce the impacts of drift.
Nozzles: 80 or 110 degree flat fan nozzles. Larger orifice nozzles (e.g. 02 or 03) or air induction nozzles are used to reduce drift but water volumes need to be about 80 L/ha or more for good coverage of small weeds.
Pressure: 150-400 kPa is a typical set up for boom sprays.

13 SPRAYER DECONTAMINATION:

Clean Up:
Clean soon after spraying to reduce the risk of forming dried deposits that may be difficult to remove.
Remove filters and clean separately. Rinse with soapy water (e.g. 500 mL or g of Drive, Dynamo, Omo or Surf per 100 L water) or water plus 0.25% wetting agent and run through boom. Rinse with water.
Decontamination:
Remove filters and clean then soak in 500 mL household ammonia in 10 L water for 30 minutes.
Rinse sprayer with soapy water (e.g. 500 mL or g of Drive, Dynamo, Omo or Surf per 100 L water) or water plus 0.25% wetting agent and run through boom. Fill with 1% solution of ammonia and allow to stand for several hours. Triple rinse with water. Or use a commercial spray tank and equipment cleaner.
Rinse nozzles and filters in water and replace.
Check and clean filters and nozzles again if necessary.
It may not be possible to decontaminate old spray tanks and hoses.
Don't use chlorine based cleaners.

14 HERBICIDE RESISTANCE:

Tolerant plants are expected to occur and may dominate the weed population after repeated applications.
Some plants have developed some resistance to 2,4-D.
In 2008 there was no known resistance to Pyraflufen.

15 REPLANTING INTERVALS:

Plant back periods in days for various rates of application

Crop	<500 mL/ha	500-900 mL/ha
Balansa clover	7	7
Barley	1	1
Canola	14	21
Chickpea	7 (14 Qld)	14
Clover; Subterranean	7	7
Clover; White	7	7
Cotton	10	14
Faba Bean	7	7
Field Pea	7	14
Lentils	7	7
Linseed	7	7
Lucerne	7	7
Lupin	7 (28 WA)a	14 (28 WA)a
Medic	7	7
Narbon Bean	7	7
Navy Bean	10	10
Oat	3	3
Perennial Ryegrass	7	7
Persian Clover	7	7
Phalaris	7	7
Rice	7	7
Safflower	7 (14 Qld)	14
Sorghum	3 (1 Qld)	7 (1 Qld)
Soybean	14	14
Sunflower	7 (1 Qld)	10 (1 Qld)
Triticale	1	3
Vetch	7	7
Wheat	1	3

These plant backs are generally quite conservative and problems are rarely seen with shorter periods because most of the free 2,4-D ester evaporates within a day or two of spraying. If applied to dry soil then the plant back period refers to the time required after the soil is wet for the broad leaved crops.
a Lupin replanting interval from label. Seems excessive.

16 WITHHOLDING PERIODS:

Crop	Type	Time
All	Harvest	Not required.
All	Grazing	7 days

17 RE-ENTRY PERIOD:

Wear protective clothing if working in the crop before the spray has dried.

18 PROTECTIVE CLOTHING:

Face shield or goggles, cotton overalls, gloves, boots.

19 SOIL:

No particular effects.

20 MODE OF ACTION:

2,4-D: Post-emergent. Disrupts cell growth and elongation. Multiple sites of action.
Pyraflufen: Aryl triazolinone or phenyl pyrazole group. Protox inhibitor. Disrupts cell membranes.

Uptake and translocation:

2,4-D EHE: Foliar absorbed with virtually no root absorption.
High concentrations may cause leaf burn and poor translocation leading to poor weed control.
Translocated both up and down from the site of application to sources of active growth.
Pyraflufen: Contact action and rapidly absorbed but not translocated.

Physiological effects:

2,4-D: Causes twisting, swelling and splitting of soft stems and abnormal growth of leaves often resulting in cupping and inter veinal chlorosis. Flowers are often deformed and seed viability may be affected. These symptoms may occur at very low dose rates.
2,4-D decreases nitrate reductase in the plant and this results in an increased nitrate level. In some plants, such as Capeweed, Radishes, Turnips, and Canola, this may reach toxic levels.
Pyraflufen: Interferes with chlorophyll synthesis by inhibiting the protoporphyrinogen IX oxidase (Protox) enzyme in chloroplasts. This leads to accumulation of protoporphyrinogen IX resulting in peroxidation of foliar cell membrane lipid under the presence of light, with subsequent cell membrane destruction and necrosis.

Residual Life and Breakdown:

Short residual life and quick breakdown.

21 SELECTIVITY:

2,4-D: Most grasses are tolerant to 2,4-D. Woody plants have lower tolerances and soft broad leaved species are generally susceptible to rates around 1 kg a.e./ha.
Crop effects are usually only noticeable if applied at the incorrect growth stage and/or excessive rates.
Plant roots absorb polar (salt and amine) forms of 2,4-D most readily and leaves absorb non polar (ester) forms most readily. Salt formulations have negligible vapour pressure are the safer to use in close proximity to sensitive plants whereas ester formulations are generally safer prior to planting susceptible crops.

Crop tolerance:

Varietal sensitivities:

Effect on Clover Species:

Damages Clovers especially at the higher rates.

Effect on Medic Species:

Kills Medics.

Effect on Lucerne:

Kills seedlings and damages established plants. Herbicide drift onto lucerne can cause damage.

Effect on Native Plants:

Most native plants will tolerate low levels of 2,4-D and drift is not expected to cause significant long term effects on roadside trees or vegetation if reasonable care is taken to avoid exposure.

23 PLANT SYMPTOMS:

Initial symptoms are usually apparent in 1-7 days and include yellowing followed by browning of the leaves, twisting of soft stems, cupping of leaves and erection of rosette leaves. Malformed growth may take weeks to develop. Death of young plants usually occurs within a month. Older and more woody plants may take several months to die.
It usually disrupts flowering and seed production or viability.
The table below summarises the effects of 2,4-D esters on the most sensitive species tested.

Species	Growth stage	Formulation	EC25 g a.e. /ha	NOEC g a.e./ha
Onion (Monocot)	Seedling	2,4-D IPE (ester)	11	6.3
Lettuce (Dicot)	Seedling	2,4-D IPE (ester)	0.9	0.53
Corn (Monocot)	Vegetative	2,4-D IPE (ester)	226	28.2
Lettuce (Dicot)	Vegetative	2,4-D IPE (ester)	6.8	1.4

Table adapted from EPA 738-R-05-002, June 2005

For sensitive species like Lettuce and Tomato, rates around 3 mL/ha of 2,4-D ester can cause symptoms.
For cereals the ester formulations are less damaging to the crop pre planting than the amine formulations.

SECONDARY EFFECTS:

Sugar contents of sprayed plants normally increase within a week of spraying and this may make the plants more palatable to herbivores including sheep and insects. This may cause stock problems if toxic plants are present.

24 TOXICITY:

Summary:

Harmful if swallowed. May cause sensitisation by skin contact. May cause lung damage if swallowed.
Pyresta is generally of low toxicity to mammals, birds and bees. It can be highly toxic to algae and some aquatic organisms.

Details:

2,4-D:
Poison schedule - S5.
Mammalian toxicity - Moderate.
Acute oral LD50 - 720-982 mg/kg (rats, 2,4-D 2EHE), [For comparison table salt is 3000 mg/kg]
Acute dermal LD50 - >2000 mg/kg (rat, 2,4-D 2EHE).
Skin - Mild skin irritant. Prolonged contact may cause skin sensitisation.
Eye - Not an irritant.
Vapour inhalation - LC50 - >5.4 mg/L air (rat, 2,4-D 2EHE).
Chronic oral toxicity NOEL - 1-50 mg/kg for two years.
The weight of evidence indicates that it is not carcinogenic or mutagenic but some animal studies have shown effects.
Data indicates that it is not teratogenic and has no reproductive effects.
Acceptable Daily Intake (ADI) - 0.01 mg/kg/day.
NOEL - 1 mg/kg/day.
Chronic effects: Repeated absorption of large amounts of 2,4-D may damage the liver and kidneys.

Pyraflufen:
Poison schedule: S5
Mammalian toxicity: Low.
Acute oral LD50: Pyraflufen-ethyl >5000 mg/kg (rat), [For comparison table salt is 3000 mg/kg]
Acute dermal LD50: Pyraflufen-ethyl > 2000 mg/kg (rat).
Skin: Product may cause sensitisation. Active ingredient not irritating in rabbits or sensitising in Guinea pigs.
Eye: Product may irritate eyes. Active ingredient not irritating in rabbits.
Vapour inhalation: May irritate mucous membranes and respiratory tract. LC50 Pyraflufen-ethyl > 5.03 mg/L air (rat).
Chronic oral toxicity: NOEL mg/kg for two years.
Not carcinogenic, mutagenic or teratogenic in animal studies (i.e. does not cause cancer or reproductive problems in animal tests).
Acceptable Daily Intake (ADI): 0.2 mg/kg bw/day.
No Observable Effect Level (NOEL): 20 mg/kg bw/day.

Other Species:

2,4-D:
Birds - Not toxic. LD50 >663 mg/kg (Mallard Ducks)
Fish - Moderate toxicity. LC50 (96 hour) >0.24 on inland silverside to 20 mg/L on bluegill sunfish for 2,4-D 2EHE technical.
Invertebrates - Moderate toxicity. EC50 (48 hour) 5.2 mg/L (Daphnia magna) for 2,4-D 2EHE technical.
Bees - Low toxicity. LD50 >100 ug/bee to 11.4 ug/bee. Moderate doses may impair brood production in honey bees. Lower doses appeared to increase longevity.
Algae - Low toxicity. EC50 (120 hour) >30 mg/L on Selenastrum capricornutum for 2,4-D EHE technical .

Pyraflufen:
Birds: Low toxicity. LD50 >200 mg/kg (Mallard Duck and Bobwhite Quail)
Fish: Low toxicity LC50 > mg/L. NOEC >100 ug/L.
Invertebrates: Probably toxic.
Bees: toxicity.
Arthropods: toxicity.
Earthworms:
Algae: High toxicity.
Accumulation:

25 TOXICITY SYMPTOMS:

Inhalation of the solvents may cause headache, nausea and intoxication.
Swallowed - Ingestion of large amounts may cause headache, nausea, lethargy, motor weakness and incoordination. (16 g.a.e. consumed over 32 days by humans has caused these effects). Chronic overexposure may present a risk to the liver and kidneys.
Skin - High or prolonged exposure may cause defatting, dermatitis and sensitisation. In some people a skin rash can occur which may be severe.
Eyes - May irritate eyes. Prolonged exposure may cause damage to eyes.

26 FIRST AID:

If SWALLOWED: Do NOT induce vomiting for small ingested quantities of less than a tablespoon. Give a glass of water. For large ingestions consider vomiting on medical advice but take care to avoid vomit entering lungs. Do not give anything by mouth to a semi conscious patient. Concentrate is considered harmful if swallowed. See a doctor.
If in EYES: Irrigate with plenty of water. See a doctor if symptoms develop or persist.
If on SKIN: Rinse with plenty of water, remove contaminated clothing, wash with soap and water. If redness, swelling, blistering or irritation occurs then see a doctor.
If INHALED: Remove patient to fresh air. See a doctor if symptoms develop or persist.
Advice to doctor: Treat symptomatically. Product contains hydrocarbon solvents. Aspiration of vomit into the lungs can cause bronchopneumonia and pulmonary oedema or pulmonary pneumonitis. Effects may be delayed.
Contact the Poisons Information Centre on 131126.

27 ENVIRONMENTAL FATE:

2,4-D EHE:
Half life in soil: 2,4-D EHE 1-14 days with an average of 2.9 days. It degrades more slowly on foliage and leaf litter. 2,4-D acid has a aerobic soil half life of 6.2 days.
Half life in water: Less than 24 hours in aquatic environments for 2,4-D EHE, BEE and IPE. Probably longer in clean water. 2,4-D acid has an aerobic half life of 15 days and an anaerobic half life of 41-333 days.
2,4-D acid is stable to abiotic hydrolysis with a half life of 1-2 years.
It has an EPA classification for soil mobility that ranges from intermediate to very mobile. Usually very low mobility in field studies even though laboratory solubility studies indicate 2,4-D is potentially mobile. Rapid degradation in the soil and removal from soil by plant uptake minimizes leaching under realistic application conditions.
Ground water contamination: Significant ground water contamination not likely but it has been detected in ground and surface waters in the US and Canada. Rarely detected more than 500 mm deep in soils.
Accumulation in milk and tissues - Does not accumulate. Not metabolised in the body. Excreted within a few days in urine.
pH stability:
Photolysis rate: 2,4-D acid half life (DT50) was 12.9 days in water at pH 5 and 68 days in soil.
Hydrolysis half life: Stable to abiotic hydrolysis.
Biodegradation rate: 2,4-D acid half life is 6.9 days in aerobic soils and 15 days in aerobic aquatic environments. 2,4-D amine and salt formulations are similar. 2,4-D esters form the 2,4-D acid with a half life of about 3 (1-10) days then follow the acid degradation pathway with a half life of about 7 days. Most field studies show an apparent half life of 1.7 - 13 days with an average of 5 days in moist soils. In dry soils the half life is much longer because most of the breakdown is due to microbial activity. The half life in grass and thatch was < 7 days on average. The half life in natural water is 1-2 weeks but may be only a few days in rice paddies.
2,4-D degrades through several low toxicity intermediates to carbon compounds, CO2, water and chlorine or HCl.
Spray drift may cause damage.

Pyraflufen:
Readily biodegradable.
Half life in soil:
Half life in water: days at pH5 and 35 C.
It has an EPA classification for soil mobility that ranges from
Ground water contamination
Accumulation in milk and tissues.
pH stability:
Photolysis rate:
Hydrolysis half life:
Biodegradation rate:

28 REGISTERED CROPS:

See HerbiGuide Species Solution tab.

29 REGISTERED WEEDS:

See HerbiGuide Species Solution tab.

30 REGULATION AND LEGAL:

APVMA Number: 61328
CAS number: 2,4-D EHE 1928-43-4. Pyraflufen-ethyl 129630-19-9.
PC Code: 2,4-D 030063
UN number: 3082 (sea transport)
Hazchem code: 3Z.
NOHSC classification: Hazardous.
Land transport:
Dangerous goods class: Not a dangerous good.
Sea transport:
Proper shipping name: ENVIRONMENTALLY HAZARDOUS SUBSTANCE, LIQUID, N.O.S. (contains 2,4-D 2 ethyl hexyl ester)
Class: 9.
Packaging group: III
EPG:
Restricted spraying areas apply in some states.
A permit is required for spraying between 15^th September and 15^th April in Tasmania.

31 PROPERTIES:

2,4-D EHE:
2,4-D 2-ethylhexyl ester (2-EHE)

Colour:
Odour: Hydrocarbon.
Form: Liquid.
Empirical formula: C16H22Cl2O3 (2,4-D 2-EHE).
Water solubility at 25 C. - Disperses in water. Emulsifiable.
Oil solubility -
Octanol:Water ratio at 25 C LogPow - 5.78 for 2,4-D 2-EHE.
Soil organic carbon absorption coefficient (Koc) 31.2-470.9 mL/g.
Vapour Pressure at 25 C. - 0.48 mPa (2,4-D 2-EHE)
Dissociation constant - pKa
Melting point - -5 C.
Boiling point - >200 C (2,4-D 2-EHE).
Molecular weight - 333.27 (2,4-D 2-EHE).
Bulk density -
Specific gravity - 1.059 for Pyresta
pH -
Flammability - Non flammable. Concentrate is combustible (C1 combustible liquid). May emit toxic fumes on burning. Not explosive, however vapours may accumulate in low areas, explode and flash back considerable distances in fires.
Flashpoint > 63 deg C. Combustible.
May react violently with strong oxidising agents
Soil DT50 aerobic 20 C - 1.7 days.
Soil DT50 anaerobic 20 C - 333 days (aquatic study).
Hydrolysis: 1-2 years sterile water pH 7 buffered.
Photolysis water DT50 13 days (artificial sunlight)
Photolysis soil DT50 68 days
Shelf Life: 5 years.
(When Stored under Ideal Conditions)

Pyraflufen-ethyl:
Colour: White milky liquid.
Odour: Slight odour.
Form: Liquid. Soluble concentrate.
Chemical name: Pyraflufen-ethyl. Ethyl 2-chloro-5-(4-chloro-5difluoromethoxy-1-methylpyrazol-3-yl)-4-fluorophenoxyacetate (IPUAC).

CAS 129630-19-9
Empirical formula: C₁₅H₁₃Cl₂F₃N₂O₄
Water solubility: Product miscible in water. Active 0.0-82 mg/L.
Oil solubility of active: Heptane: 234 mg/L, Methanol: 7.39 g/L, Dichloromethane: 100-111 g/L, Acetone: 167-182 g/L, P-xylene: 41.7-43.5 g/L, Ethyl acetate: 105-111 g/L
Octanol:Water ratio: LogPow = 3.49
Soil organic carbon absorption coefficient (Koc):
Vapour Pressure: 1.6 x 10^-8 Pa at 25 C.
Henry's Law constant 8.1 x 10^-5 Pa.m³/mol
Relative Vapour Density: >1 (air=1)
Dissociation constant: Does not dissociate.
Melting point: 126.4-127.2 ⁰C for active.
Boiling point: about 100 C.
Molecular weight: 413.2
Bulk density: 1.565 g/cm^-3 for active at 24 ⁰C.
Specific gravity: 1.02-1.03.
pH: 6.5-7. 6.84 at 24 ⁰C.
Flammability: Not flammable. Not combustible. Dried residues may burn and emit toxic fumes.
Flashpoint: No flash at temperatures up to 100 C. Not explosive.
Autoignition: C.
Corrosivity:
Oxidising properties: Not oxidising.
Shelf Life: 3 years. (at least 26 months).
(When Stored under Ideal Conditions)
Temperature stability: No loss after 14 days at 54 ⁰C. No separation of suspended material at low temperatures.
Foaming: Non foaming.
Viscosity: Non Newtonian.
Surface tension: 39.2 mN/m for product. 45.9 mN/m at 1:200 dilution. 74.2 mN/m for active at 20 ⁰C
Suspensibility: 97.6% at 1:200 dilution.
Particle size: <38 um.

32 SPILLS:

Absorb spill with earth, sand, clay or absorbent material.
Ventilate area after cleanup. Slippery when spilt. Wash area with water plus detergent and dispose of waste water in a chemical pit.

33 FIRE:

Use foam or preferably alcohol resistant foam for fire fighting.
Extinguish with water spray, foam, carbon dioxide or dry agent.
Toxic fumes may be released in fire. Wear breathing apparatus or avoid smoke.
Product non flammable. Concentrate is combustible (C1 combustible liquid). Not explosive, however vapours may accumulate in low areas, explode and flash back considerable distances in fires.

34 COMMENTS:

2,4-D decreases nitrate reductase in the plant and this results in an increased nitrate level. In some plants, such as Capeweed, Radishes, Turnips, and Canola, this may reach toxic levels.

35 REFERENCES:

Ashton, F.M. and Crafts, A.S. (1981) Mode of Action of Herbicides. (Wiley-Interscience publication).

Kearney, P.C. and Kaufman, D.D. (1976). Herbicides. Chemistry, degradation and mode of action. Vol 1 & 2.

Nufarm MSDS (September, 2005).

Sipcam (2008) Pyresta label.

Sipcam (2008) Pyresta MSDS.

Summit Agro (2007) Label 60493/0707.

Summit Agro (2007) MSDS June 2007.

Acknowledgments:

Collated by HerbiGuide. For more information see www.herbiguide.com.au or phone 08 98444064.