Pyroxasulfone

1 Trade nameManufacturerForm
SAKURA 850 WG HERBICIDEBAYER CROPSCIENCE PTY LTDWATER DISPERSIBLE GRANULE

2 PRICE:

$373.82/kg

3 ACTIVE INGREDIENTS: Pyroxasulfone 850g/kg

4 CHEMICAL GROUP: K

Pyrazole or isoxazoline group.

5 RELATED HERBICIDES:

ButisanMetazachlor 500g/L
DevrinolNapropamide 500g/kg
DualMetolachlor 720g/L
Dual GoldS-Metolachlor 960g/L
FrontierDimethenamid-P 720 g/L
Ramrod FlowablePropachlor 480g/L
SakuraPyroxasulfone 850g/kg

6 GENERAL DESCRIPTION:

A pre-emergence, selective, translocated, mainly root absorbed, residual agricultural herbicide for the control of small seeded grasses, small seeded broadleaved weeds and rushes in some cereal and broadleaved crops.

7 APPLICATION METHODS AND TIPS:

Best results when applied to bare moist soil, incorporated by the planting operation and rain follows to assist uptake by weeds.

Normally applied prior to planting and incorporated by planting.

Incorporate as soon as possible and within 3 days of spraying. This is to reduce runoff and environmental contamination and has little effect on weed control.

Ensure thorough even coverage. Application to ridged, cloddy or where more than 50% stubble cover may result in poor weed control.

Use higher water rates where stubble has been retained.

Avoid burying weed seeds by cultivation as root absorption of the herbicide on the surface soil will be reduced and poor weed control may occur.

Heavy rain after application may leach herbicide out of the root zone resulting in poor weed control and it may wash herbicide into the furrows causing crop damage.

Control emerged weeds with a knockdown herbicide.

Avoid throwing treated soil into planting furrow to reduce the risk of crop damage. Avoid using a combination of press wheels and covering harrows or chains as this may concentrate herbicide laden soil over the planting rows and cause crop damage. Wind or water erosion of herbicide laden soil into crop furrows may also cause crop damage.

Crops that are growing slowly after planting are more susceptible to damage. Waterlogging, frost, disease, insect attack, some seed dressings or low vigour seed may are common causes of slow initial crop growth.

Keep agitated.

Do not apply if heavy rain is expected within 48 hours.

Do not apply to waterlogged soil.

To avoid drift do not apply when surface temperature inversions occur, when wind speed is more than 20 kph or less than 3 kph and use nozzles that apply coarse or very coarse droplets.

8 WEATHER:

Rainfast immediately for pre emergent applications.

Frost effects: Cold frosty conditions may reduce crop vigour and make it more susceptible to damage.

Wind: No significant effect.

Inversions: Avoid application during low level inversions as excessive drift may occur.

Temperature: Cold conditions may reduce crop vigour and make it more susceptible to damage.

Delta T and relative humidity: No significant effects.

9 ADJUVANTS:

Wetting agents: Not required.

Spray oils: Not required.

10 WATER QUALITY:

Hard water:

Salty water:

Colloids:

pH:

Tank life: Several days.

11 COMPATIBILITY:

Add pyroxasulfone first and ensure it is fully dispersed before adding other products.

Trace elements.

See HerbiGuide Compatibilities button.

Incompatible with strong acids and bases.

12 EQUIPMENT:

Use equipment with good agitation.

Boom sprays:

Carrier volume: 50-100 L/ha. Use higher volumes in stubble retention systems.

Nozzles: Flat fan.

Pressure: 150-400 kPa.

Droplet size: Coarse droplet size recommended by supplier to reduce drift.

Aerial application:

Not generally recommended for aerial application.

Carrier volume: 30 L/ha

13 SPRAYER DECONTAMINATION:

Clean Up:

Clean soon after spraying to reduce the risk of forming dried deposits that may be difficult to remove. Mechanically removed any caked deposits.

Remove filters and clean separately. Triple rinse with water or water plus 0.25% wetting agent and run through boom.

Decontamination:

Remove filters and clean separately.

Rinse with water and drain.

Quarter fill the tank with an alkali detergent (eg 500 mL or g of Drive, Dynamo, Omo, or Surf per 100 L water) and circulate for at least 15 minutes then run through boom. Rinse with water. Remove filters and clean separately. Replace them and rinse the whole system with water again.

14 HERBICIDE RESISTANCE:

Tolerant plants are expected to occur and may dominate the weed population after repeated applications.

15 REPLANTING INTERVALS:

CropTimeMinimum interim rainfall
Barley9 months150 mm
Beans; Faba9 months250 mm
Beans; Mung5 months150 mm
Canola9 months250 mm May be some stunting
Chickpea9 months250 mm
Clover; subterraneum9 months250 mm
Cotton5 months150 mm
Lentils9 months250 mm
Lucerne21 months550 mm
Lupins9 months250 mm
Maize5 months150 mm
Medic21 months550 mm
Oats21 months550 mm
Peas; Field9 months250 mm
Sorghum5 months150 mm
Soybeans5 months150 mm
Sunflower5 months150 mm
Triticale0 months0 mm
Vetch9 months250 mm
Wheat (except Durum)0 months0 mm
Wheat; Durum21 months550 mm

16 WITHHOLDING PERIODS:

CropTypeTime
AllGrazingNot required
AllHarvest6 weeks.

17 RE-ENTRY PERIOD:

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

18 PROTECTIVE CLOTHING:

Overalls, boots and a washable hat. Use gloves and face shield when handling the concentrate.

Repeated exposure may lead to allergic reactions. Sensitive workers should wear protective clothing.

A respirator is not usually required during normal use.

19 SOIL:

Soil texture: Leaching may occur on sandy soils after heavy rain and result in poor weed control and increased risk of damage to the crop.

Good activity in fine to coarse textured soils.

Soil pH:

Soil organic matter: Breaks down faster in soils with high organic matter.

Soil moisture at application: Needs good soil moisture for best results.

20 MODE OF ACTION:

A pre-emergence, selective, translocated herbicide that inhibits meristematic growth. Weeds absorb the herbicide soon after germination and may grow for a few days or weeks before dying.

Pyrazole, isoxazoline or chloroacetamide group of chemicals

Inhibits very long chain fatty acid production which disrupts shoot elongation.

Uptake and translocation:

Mainly root absorbed with some uptake by the shoots of germinating plants.

Physiological effects:

Residual Life and Breakdown:

Residual for several weeks. The half life in the soil is 16-26 days.

21 SELECTIVITY:

Crop tolerance:

Wheat, corn, soybean and sunflower are tolerant.

Corn tolerates 300-500 g.a.i./ha without yield loss normally.

Varietal sensitivities:

Durum wheat is sensitive.

Varieties with short coleoptile lengths are more prone to damage.

Effect on Clover Species:

Damages clover.

Effect on Medic Species:

Damages medics.

Effect on Lucerne:

Effect on Native Plants:

Large seeded broadleaved species are usually tolerant.

22 DISEASE AND INSECT EFFECTS:

No specific effects apart from reducing crop vigour which may increase the risk of herbicide injury.

23 PLANT SYMPTOMS:

Compacted growth, reduced root lengths, twisted leaves.

SECONDARY EFFECTS:

24 TOXICITY:

Summary:

Pregnant women and children should avoid contact with this herbicide.

Repeated exposure may cause allergic reactions.

Details:

SUSMP classification (Poison schedule): S6.

Mammalian toxicity: Low.

Acute oral LD50: Low toxicity. >2000 mg/kg (rat), [For comparison table salt is 3000 mg/kg]

Acute dermal LD50: Low toxicity. >2000 mg/kg (rabbit).

Skin: Non irritating but the formulated product is sensitising in Guinea pigs. The active constituent, pyroxasulfone, was not irritating on rabbits or sensitising in Guinea pigs.

Eye: Slight irritant (Rabbit). May irritate eyes.

Vapour inhalation: Low toxicity. LC50 >5.8 mg/L air (rat).

Limited evidence of a carcinogenic effect.

Not mutagenic or teratogenic in animal studies (i.e. did not cause reproductive problems in animal tests).

Chronic oral toxicity: NOEL mg/kg for two years.

Acceptable Daily Intake (ADI):



Chronic toxicology from Bayer MSDS

Repeated oral doses of the product in rats, mice and dogs led to changes in clinical chemistry values, increased liver weight, and other effects on the liver, heart, other muscles, and nerve tissues. Immunotoxicity studies in rats and mice produced no effects on immune systems. Mutagenicity studies were also negative. Increased incidence of urinary bladder transitional cell papillomas (benign) was reported in male rats in a two year carcinogenicity study. Effects on fertility or embryo development were not observed in rat one-generation and two generation reproductive toxicity studies at the dosage where general toxicity to parental animals was observed, however developmental neurotoxicity was observed in offspring in a rat study.

Other Species:

Toxic to aquatic life.

Birds: Low toxicity. D50 >2250 mg/kg bobwhite quail.

Fish: toxicity: High toxicity. LC50(96 hr) >2.2 mg/L rainbow trout.

Invertebrates: toxicity. EC50(48 hr) >4.4 mg/L Daphnia magna

Bees: Low toxicity. >100 ug/bee

Arthropods: toxicity.

Earthworms:

Algae: High toxicity. ErC50(96 hr) 0.00079 mg/L Pseudokirchneriella subcapitata

Accumulation:

25 TOXICITY SYMPTOMS:

No specific symptoms reported.

26 FIRST AID:

If SWALLOWED: Wash out mouth with water. Do NOT give anything by mouth to a semiconscious or unconscious patient. Do NOT induce vomiting.

If in EYES: Hold eyelids open and wash eyes with plenty of water for 5 minutes, remove contact lenses if present and wash for a further 10 minutes. See a doctor if symptoms persist.

If on SKIN: Remove contaminated clothing. Wash skin thoroughly with soap and water.

If INHALED: Remove patient to fresh air. See a doctor if symptoms persist.

Advice to doctor: There are no reports of poisonings in humans. Treat symptomatically. No antidote. Gastric lavage may not be necessary due to the low toxicity of the compound. However, administration of activated charcoal and sodium sulphate is advisable with significant ingestions.

Contact the Poisons Information Centre on 131126.

27 ENVIRONMENTAL FATE:

Degraded by microbial action and is faster in warm, moist and high organic matter soils,

Half life in soil: 16-26 days.

Half life in water: Approximately 32 hours field half life at typical temperatures.

It has an EPA classification for soil mobility of mobile.

It has a leaching index of . (for comparison, trifluralin is 0-1 and chlorsulfuron is 25-30).

Ground water contamination:

Accumulation in milk and tissues:

pH stability:

Photolysis rate:

Hydrolysis half life:

Biodegradation rate:

Bioconcentration factor (BCF):

28 REGISTERED CROPS:

See HerbiGuide Species Solution tab.

29 REGISTERED WEEDS:

See HerbiGuide Species Solution tab.

30 REGULATION AND LEGAL:

UN number: 3077

CAS numbers: 447399-55-5

OPP Chemical Code:

Hazchem code: 2Z

NOHSC classification: Hazardous.

Land transport: ADG

Dangerous goods class (ADG): Not a dangerous good.

Sea transport: IMDG

Proper shipping name: ENVIRONMENTALLY HAZARDOUS SUBSTANCE, SOLID, N.O.S. (contains pyroxasulfone)

International Maritime Dangerous Goods Code (IMDG):

Class: 9

Packaging group: III

EPG:

Marine pollutant.

Air transport: IATA/ICAO



Risk phrases:

R40 (Carcinogen. Cat 3) - Limited evidence of a carcinogenic effect

R43 - May cause sensitisation by skin contact

R48/22 - Danger of serious damage to health by prolonged exposure if swallowed

R61 (Reproductive. Cat 2) - May cause harm to the unborn child

Safety phrases:



Mandatory no-spray zones: Do not apply if there are aquatic and wetland areas including aquaculture ponds, surface streams and rivers within 80 metres downwind from the application area.

Record keeping: Users must record application details within 24 hours and keep them for 2 years. Details of the information required are on the HerbiGuide spray records form.

31 PROPERTIES:

Colour: Light brown

Odour: Slight and characteristic

Form: Granule

Chemical name: Pyroxasulfone.

Empirical formula:

IUPAC:

CAS: 447399-55-5

Water solubility: 3.48 mg/L at 20 C at pH

Oil solubility:

Octanol:Water ratio: LogPow = 2.39 at 25 C at pH .

Soil organic carbon absorption coefficient (Koc):

Vapour Pressure: 2.4 x 10-6 Pa at 25 C.

Vapour density:

Dissociation constant: pKa

Melting point: 130.7 C.

Boiling point: C.

Molecular weight:

Bulk density: 0.6-0.7 g/mL

Specific gravity:

Viscosity: CPS.

pH: 9.5 at 1% dilution.

Flammability: Not flammable.

Flashpoint: C.

Autoignition: C.

Corrosivity:

Shelf Life: Several years.

(When Stored under Ideal Conditions)

Stable in normal storage.

Avoid extreme temperatures and direct sunlight.

32 SPILLS:

Shovel or sweep up and place in plastic drums. Avoid creating dust by damping down with a small amount of water if necessary. Wipe down area with a damp cloth.

Prevent spilled material from entering watercourses and prevent washings from entering watercourses.

33 FIRE:

Extinguish with water spray, foam, carbon dioxide or dry agent.

Toxic fumes may be released in fire. Wear breathing apparatus or avoid smoke.

34 COMMENTS:

History

Was KIH-485 as the experimental product by Kumiai and developed by Bayer in Australia for the wheat market.

Being developed for corn and soybeans in the US.

35 REFERENCES:

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

Bayer 2011 Sakura Label and MSDS.

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


Acknowledgments:

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