Iodosulfuron 50
| 1 Trade name | Manufacturer | Form |
| HUSSAR SELECTIVE HERBICIDE | BAYER CROPSCIENCE PTY LTD | WG |
2 PRICE:
3 ACTIVE INGREDIENTS: Iodosulfuron 50g/kg + mefenpyr
4 CHEMICAL GROUP: B Sulfonylurea
5 RELATED HERBICIDES:
| Broadstrike | Flumetsulam 800g/kg |
| Chlorsulfuron | Chlorsulfuron 750g/kg |
| Crusader | Pyroxulam 30g/L |
| Eclipse | Metosulam 100g/L |
| Eclipse | Metosulam 714g/kg |
| Ethoxysulfuron | Ethoxysulfuron 600g/kg |
| Express | Tribenuron methyl 750g/kg |
| Flame | Imazapic 240g/L |
| Harmony M | Metsulfuron 68g/kg + thifensulfuron 682g/kg |
| Imazapyr | Imazapyr 250g/L or 750g/kg |
| Intervix | Imazamox 33g/L + imazapyr 15g/L |
| Iodosulfuron 100 | Iodosulfuron 100g/kg |
| Iodosulfuron 50 | Iodosulfuron 50g/kg + mefenpyr |
| Lightning | Imazapyr 175g/L + imazethapyr 525g/L |
| Logran 750 | Triasulfuron 750g/kg |
| Londax | Bensulfuron 600g/kg |
| Mesosulfuron 30 | Mesosulfuron 30g/L |
| Metsulfuron-methyl | Metsulfuron 600g/kg |
| Monza | Sulfosulfuron 750g/kg |
| Muster | Ethametsulfuron methyl 750g/kg |
| OnDuty | Imazapic 525 + Imazapyr 175g/L |
| Raptor WG 700 | Imazamox 700 g/kg |
| Sempra | Halosulfuron 750g/kg |
| Spinnaker | Imazethapyr 700g/kg or 240g/L |
| Sulfometuron | Sulfometuron 750g/kg |
| Titus | Rimsulfuron 250g/kg |
| Trifloxysulfuron | Trifloxysulfuron 750g/kg |
6 GENERAL DESCRIPTION:
Iodosulfuron is used mainly as a post emergence herbicide for control of a range of grass and broad leaf weeds in wheat and turf.
It is a selective and translocated herbicide that is absorbed through the leaves and roots. It is of low toxicity to mammals, birds and fish. Iodosulfuron acts on the AHAS (acetohydroxyacid synthase) enzyme in plants which is not present in animals and this is the main reason for its low toxicity. It presents little hazard to the environment because it is used at low rates and degrades relatively quickly in most field situations. Plants resistant to iodosulfuron have developed and are expected after repeated use.
Many Annual Ryegrass populations in cropping areas are resistant to Iodosulfuron and other group B herbicides.
7 APPLICATION METHODS AND TIPS:
Add a non ionic wetting agent or spraying oil such as Hasten®. Some spraying oils increase weed control but may cause crop damage.
Iodosulfuron is usually mixed with 30-100 l water per hectare and broadcast through hydraulic nozzles. It can be applied in ultra low volumes of carrier.
Acidifiers may increase iodosulfuron absorption, especially on waxy plants.
Weeds are most sensitive and crops most tolerant of iodosulfuron when they are young and actively growing. Under cold, wet or stressful conditions the weeds become more tolerant and the crop less tolerant of the herbicide.
For each 10 degree drop in temperature the crops ability to break down iodosulfuron drops by a factor of 2 to 5, thus under cold conditions crop damage is more likely.
Rain within 8 hours of application may reduce the effectiveness of post-emergence applications. Most of the herbicide is washed off leaves by the first 4 mm of rain.
Temperature and relative humidity have little effect on the effectiveness of iodosulfuron apart from their indirect effect on plant growth rates.
Crops physically damaged by wind, sandblasting, hail or insect attack may be damaged by the application of iodosulfuron.
Some crop yellowing and growth retardation may occur within a month of spraying especially if the crop is stressed.
Applications on dry sandy soils followed by leaching rains may result in crop damage.
Crop damage may occur on highly alkaline soils with a pH>8.5.
Avoid mowing turf for 3 days before or after application. Don't feed clippings to stock for slaughter as MRL's have not been set.
8 WEATHER:
Rainfast in 8 hours.
Frost effects: Frosts immediately prior to, during and after application may result in reduced efficacy because the weeds may be stressed and the risk of crop damage increases because the crop is detoxifying the herbicide more slowly.
Wind:
Inversions: Avoid application during low level inversions as excessive drift may occur.
Temperature: In cold conditions, effects on the crop will be greater.
Delta T and relative humidity: Avoid application when Delta T is greater than
9 ADJUVANTS:
Wetting agents: Non ionic wetting agent is recommended on the label. This may increase the absorption of the herbicide.
Spray oils: Hasten Spray oil is recommended on the label. Other spray oils can be used to increase the absorption of the herbicide.
10 WATER QUALITY:
Hard water: May reduce its effectiveness.
Salty water: Salt up to levels accepted for stock drinking water are usually has little effect on performance. Very salty water may reduce its effectiveness.
Colloids: Little effect.
pH: Do not use with acid water. If pH of water is less than 5.5 then use a buffer to rais the pH to 7. Do not tank mix with products that acidify the water.
Tank life: About 2% of iodosulfuron activity could be lost each day it is kept in the spray tank during warm weather if the water is acidic (pH5) or acidifiers have been added. Avoid keeping the spray mix in the tank overnight because it may settle or breakdown.
11 COMPATIBILITY:
Trace elements: Iodosulfuron forms stable metal and ammonium salts so it is incompatible with most trace elements including zinc and ammonium sulphate.
Do not tank mix with products that acidify the water.
Iodosulfuron is antagonistic with diclofop and other grass herbicides.
Iodosulfuron may be synergistic with hormone herbicides and metsulfuron.
Organophosphate insecticide application within 7 days before application or 3 days after application may cause increased yellowing of turf.
Don't tank mix organophosphate insecticdes with iodosulfuron.
See HerbiGuide Compatibilities button.
12 EQUIPMENT:
Continuous agitation is required to maintain a suspension.
Boom sprays:
Carrier volume: 50-100 L/ha boom recommended on label. Rates down to 20 L/ha are used in the field providing good coverage of weeds is maintained.
Nozzles: Flat fan.
Pressure: 150-400 kPa.
Droplet size: 200-300 micron.
Filter size: 100 mesh. Finer filters may result in increased blockages.
Aerial application:
Carrier volume:
13 SPRAYER DECONTAMINATION:
Clean up:
Clean soon after spraying to reduce the risk of forming dried deposits that may be difficult to remove.
Remove nozzles and filters and clean separately. Triple rinse with soapy water (eg 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. This procedure is sufficient for spraying in other cereals or non selective applications.
Decontamination:
Remove the nozzles and filters and clean separately and allow to soak in a mixture of 500 mL chlorine bleach (4%) per 10 L water for at least 30 minutes.
Rinse sprayer with soapy water (eg 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. Drain tank and flush with clean water for a minimum of 10 minutes to remove all traces of liquid fertilisers or adjuvants containing ammonia, such as ammonium sulphate or ammonium nitrate, before adding chlorine bleach, because bleach and ammonia will react to release a toxic gas.
Fill tank with clean water and add 300 mL household chlorine (4%) bleach per 100 L water, flush through hoses and boom then stand for 15 minutes with agitation engaged, repeat. Rinse tank, hoses and boom thoroughly with clean water to remove traces of bleach.
Rinse filters and nozzles in water and replace.
14 HERBICIDE RESISTANCE:
Plant populations tolerant to iodosulfuron are expected to occur naturally after repeated use. Plants that are resistant to group B (Sulfonylurea) herbicides will normally be resistant to iodosulfuron.
Tolerant crops can be developed.
Herbicide resistance is due to plants with a less sensitive enzyme or with an increased ability to break the herbicide down.
Black Nightshade are naturally tolerant.
15 REPLANTING INTERVALS:
Some crops should not be planted for many months after iodosulfuron application. This is because they are sensitive to extremely low levels of iodosulfuron and not because of high levels of persistence of the herbicide in the soil.
| Crop | Time |
| Barley | 1 day |
| Beans | 21 months |
| Bluegrass | 9 months? |
| Canola | 9 months |
| Cereal Rye | 1 day? |
| Corn | 9 months? |
| Cotton | 9 months? |
| Flax | 9 months? |
| Guar | 9 months? |
| Lentils | 21 months |
| Lucerne | 9 months? |
| Lupins | 9 months |
| Medic | 21 months |
| Millet; Pearl | 9 months? |
| Millet; Setaria | 9 months? |
| Mung Beans | 9 months? |
| Mustard | 9 months? |
| Oats | 9 months? |
| Onions | 21 months? |
| Ornamentals | 12 months |
| Peas | 21 months |
| Potatoes | 9 months? |
| Ryegrass | 9 months? |
| Safflower | 9 months? |
| Sorghum | 9 months? |
| Soybeans | 9 months? |
| Sugar Beet | 21 months? |
| Sunflowers | 9 months? |
| Triticale | 1 day? |
| Wheat | 1 day |
16 WITHHOLDING PERIODS:
| Crop | Type | Time |
| All | Harvest | Not required |
| All | Grazing | 28 days |
17 RE-ENTRY PERIOD:
Wear protective clothing if in contact with the crop before the spray has dried.
18 PROTECTIVE CLOTHING:
Overalls, boots and washable hat. Use gloves and face shield when handling the concentrate.
19 SOIL:
Soil texture: Crop damage may occur on light sandy soils when leaching rainfall follows application.
Soil pH: Don't use on highly alkaline soil with pH>8.5. Damage to turf may occur on alkaline soils with a pH greater than 8.5.
Soil organic matter: Do not apply to soils very low in organic matter as crop injury may occur.
Soil moisture at application: Requires good soil moisture for best results. In dry soils, root uptake is reduced thus efficacy is reduced.
In waterlogged soils, poorer weed control may occur due to as plants being under stress. Crop damage may also be greater due to reduce rates of breakdown within the plant.
In soils where there are marginal levels of zinc and copper, the use of iodosulfuron on wheat may induce a deficiency in these trace elements causing a subsequent yield loss. See crop tolerance section below for remedial action.
20 MODE OF ACTION:
Group B, sulfonylurea, ALS inhibitor.
Iodosulfuron inhibits of cell division in the growing tips of roots and shoots in susceptible species. Both tolerant and susceptible species absorb iodosulfuron and its selectivity is due to faster detoxification in tolerant species.
Uptake and translocation:
Most of the iodosulfuron applied to leaves is absorbed on the day of application. Small amounts (5-10%) move out of the leaf to roots and shoot base with little moving upwards. Most is translocated in the phloem.
Broadleaf weeds have greater absorption and translocation than the grasses.
Absorption by roots from the soil solution is not as efficient.
Physiological effects:
Within the plant, iodosulfuron stops cell division very quickly by its action on the AAHAS enzyme. Secondary effects on photosynthesis, respiration and ethylene production produce the symptoms of yellowing and reddening of grasses and leaf drop in broad-leaved weeds.
The safener mefenpyr-diethyl acts by increasing the rate of breakdown of the product in crop plants.
The growth of seedlings may be stimulated at low dose rates.
It does not normally affect seed germination.
Residual Life and Breakdown:
21 SELECTIVITY:
Species tolerant to iodosulfuron such as the cereals degrade it more quickly than do sensitive plants. Differences in tolerance to post emergence applications to wheat varieties is due to differing rates of breakdown. Sensitive varieties produce less spikelets/ear. Degradation products are non toxic and herbicidally inactive.
Black Nightshade are tolerant.
Crop tolerance:
Temporary yellowing and stunting may occur.
The tolerance of crops to iodosulfuron is reduced in soils with high pH, sandy soils, soils with marginal zinc, manganese or copper levels, if leaching rains occur soon after spraying or if crops are waterlogged before or after spraying.
If soaking rains follow application to dry sandy soils the damage to turf may occur.
Turf damage may occur on alkaline soils with a pH greater than 8.5.
In soils where there are marginal levels of zinc and copper, the use of iodosulfuron on wheat may induce a deficiency in these trace elements causing a subsequent yield loss.
On areas where iodosulfuron has induced trace element deficiencies the following may reduce losses;
1 kg zinc sulphate plus
1 kg copper sulphate (or 0.5 kg copper oxychloride) plus
4 kg manganese sulphate (or 6 L Mangasol) plus
250 mL wetting agent in 100 L/ha of water applied in the cool of the day or at night.
5-7 days later spray a mix of 30 kg Urea in 100 L/ha water in the cool of the day. Pre mix urea in water to prevent freezing in the spray tank.
Varietal sensitivities:
Effect on Clover Species:
Knockdown and residual control of clovers occurs. Do not use in crops undersown with clovers or other legume pasture species.
Effect on Medic Species:
Knockdown and residual control of medics occurs. Do not use in crops undersown with medics or other legume pasture species.
Effect on Lucerne:
Damages established lucerne.
Knockdown and residual control of lucerne seeedlings occurs. Do not use in crops undersown with lucerns or other legume pasture species.
Effect on Native Plants:
Variable effects on native plants.
22 DISEASE AND INSECT EFFECTS:
Where CCN and Rhizoctonia are present crop damage may occur. Generally the disease puts the crop under stress and therefore may cause crop injury. The effects of CCN and Rhizoctonia can be accentuated after application.
23 PLANT SYMPTOMS:
Growth stops soon after post emergence applications. Seven to thirty days later plants will start to yellow or redden. In broad-leaved weeds there may be an inter venal yellowing. Annual weeds are usually dead or severely stunted within 4-6 weeks of spraying. Symptoms can be quite slow to develop and assessment of weed control should be at least 6-8 weeks after spraying. Under cold and wet conditions they may remain alive as severely stunted plants with few roots and die from water stress in spring. Iodosulfuron has little effect on germination and weeds may emerge and grow for a week or two before dying. Under hot, warm, moist conditions the plants die faster.
SECONDARY EFFECTS:
Iodosulfuron does not affect the microbes associated with N fixation in legumes.
Iodosulfuron and residues in the soil from previous applications may make the crop more susceptible to Take-All, CCN, Rhizoctonia and zinc, copper and manganese deficiency.
It has no impact on N or P nutrition of cereals.
24 TOXICITY:
Summary:
May damage eyes. Wear goggles or a face shield.
Oral Toxicity (ingestion by mouth) - Low.
Dermal Toxicity (absorption by skin) - Low.
Toxicity to Other Species - Low.
Details:
Poison Schedule - 5
Mammalian toxicity - low.
Acute oral LD50 - >5000 mg/kg (rat). [For comparison table salt is 3000 mg/kg]
Acute dermal LD50 - > 5000 mg/kg (rabbit).
Skin - Slightly irritating (rabbit). Non sensitising (Guinea pig). Repeated exposure may cause skin dryness or cracking due to the hydrocarbon solvent.
Eye - Severely irritating. Irreversible damage to eyes. (rabbit)
Vapour inhalation - Low toxicity. LC50 - > mg/L air (rat).
Chronic oral toxicity NOEL - ppm for two years.
Not carcinogenic, mutagenic or teratogenic in animal studies (i.e. does not cause cancer or reproductive problems in animal tests). Product contains naphthalene which the IAEC has calssified as a possible human carcinogen (group 2B).
Acceptable Daily Intake (ADI):
Other Species:
Birds: Low toxicity. Acute oral LD50: > 2000 mg/kg (bobwhite quail, mallard duck, Japanese quail, iodosulfuron-methyl-sodium)
Birds - low toxicity. Acute oral LD50 = 2000 mg/kg (bobwhite quail).
Fish - low toxicity: LC50 > 100 mg/L (96 hour, rainbow trout (Oncorhynchus mykiss), iodosulfuron-methyl-sodium).
LC50 = 117 mg/L (96 hour, common carp (Cyprinus carpio), iodosulfuron-methyl-sodium).
LC50 = 10 mg/L (96 hour, rainbow trout (Oncorhynchus mykiss), Hussar like product)
Invertebrates - low toxicity. EC50 = 12.2, 22.9 and >100 mg/L (48 hour, Daphnia magna, iodosulfuron-methyl-sodium) have been reported.
EC50 = 7.8 mg/L (48 hour, Daphnia magna, Hussar like product).
Bees - low toxicity. Oral LD50 > 289 ug product/bee. Contact LD50 > 481 ug product/bee.
Arthropods: toxicity.
Earthworms - Low toxicity.
Insects - Low toxicity.
Algae - very toxic. EC50 = 0.07 mg/L (72 hour, green algae (Selenastrum capricornutum), iodosulfuron-methyl-sodium).
EC50 = 0.031 mg/L (96 hour, green algae (Pseudokirchneriella subcapitata), iodosulfuron-methyl-sodium).
EC50 = 0.87 mg/L (72 hour, Pseudokirchneriella subcapitata, Hussar like product)
Aquatic plants: Very toxic. EC50 = 0.08 ìg/L (14 days, Lemna gibba)
Bacteria: Low toxicity: EC50 > 1000 mg/L (72 hour, Pseudomonas putida)
Harmless to following non-target invertebrates: Rove beetle (Aleochara bilineata GYLL), Predatory mite (Typhlodromus pyri) and Cereal aphid parasitoid (Aphidius rhopalosiphi (DESTEFANI-PEREZ))
25 TOXICITY SYMPTOMS:
Iodosulfuron in small quantities does not usually evoke any symptoms in animals.
The main enzyme (AHAS) that is attacked in plants does not occur in animals.
26 FIRST AID:
Telephone 13 11 26.
If Swallowed - do not induce vomiting. Wash mouth out with water. Keep patient at rest. Seek medical advice if symptoms develop.
If on Skin - Wash with soap and water.
If in Eyes - Wash out with water immediately and SEEK URGENT MEDICAL AID. This product may cause long term eye damage if not treated.
If inhaled - Remove patient to fresh air.
Advice to doctor - The product is a severe eye irritant and can cause irreversible damage to eyes. Consult an ophthalmologist.
For other routes of exposure treat symptomatically.
Symptoms may include headaches, dizziness, could be anesthetic and may have other central nervous system effects. May cause lung damage if swallowed.
If large amounts (more than a mouthful) have been swallowed,
the following measures should be considered: -
Carry out gastric lavage followed by charcoal (carbo medicalis) and sodium sulphate
administration.
Monitor kidney function, liver function and red blood cell count.
This product contains a relatively small amount of a hydrocarbon solvent, so care should be taken to prevent pulmonary aspiration. Small amounts aspirated into the respiratory system during ingestion or from vomiting may cause bronchopneumonia or pulmonary oedema.
Elimination by dialysis (forced alkaline diuresis).
There have been no documented cases of poisoning up to 2001.
27 ENVIRONMENTAL FATE:
Half life in soil: Soil DT50 = 1-5 days (7-10 days with low soil moisture) Its half life is much longer in soils with high pH (up to 9 months). Degradation is mainly microbial.
Half life in water: Hydrolysis half life: Abiotic hydrolysis DT50(200C) = 31 days at pH 5, >365 days at pH 7, =362 days at pH 9.
It has an EPA classification for soil mobility that ranges from
It has a leaching index of . (for comparison, trifluralin is 0-1 and chlorsulfuron is 25-30).
Iodosulfuron-methyl-sodium and its metabolites have almost no vertical movement in soil. Lysimeter and computer simulation studies indicate that neither iodosulfuron-methyl-sodium nor its metabolites would be transported to soil layers deeper than 1 metre.
Ground water contamination: It is not expected to cause ground water contamination problems due to its low leachability, relatively rapid degradation in plants and soils, low use rates and low toxicity.
Accumulation in milk and tissues: Does not accumulate in the milk or tissues of animals. Most is excreted intact in the urine of mono gastric animals or as a conjugate in ruminants.
pH stability:
Photolysis rate: Photodegradation DT50 is about 50 days.
Biodegradation rate: Little is naturally degraded due to exposure to sunlight and volatilisation. It is broken down mainly by microbial activity.
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: Iodosulfuron-methyl-sodium 144550-36-7
Mefenpyr-diethyl (crop safener) 135590-91-9
Hydrocarbon solvent 64742-94-5
Naphthalene (in hydrocarbon solvent) 91-20-3
Precipitated silica 112926-00-8
Aluminium silicate (Perlite) 93763-70-3
OPP Chemical Code:
Hazchem code: 2Z.
NOHSC classification: Hazardous.
Land transport:
Dangerous goods class (ADG): Not classified as a dangerous good for transport by road or rail.
Sea transport:
Proper shipping name: ENVIRONMENTALLY HAZARDOUS SUBSTANCE, SOLID, N.O.S. (iodosulfuron-methyl-sodium mixture). Marine Pollutant.
International Maritime Dangerous Goods Code (IMDG):
Class: 9.
Packaging group: III.
EPG:
Risk phrases:
R41 - Risk of serious damage to eyes.
R65 - Harmful: May cause lung damage if swallowed.
Safety phrases:
31 PROPERTIES:
Colour: Yelllow brown fre floating granules.
Odour: Aromatic.
Form: Granule.
Chemical name: Iodosulfuron-methyl-sodium.
Empirical formula:
IUPAC:
CAS: 144550-36-7.
Water solubility at 25 C: 25 g/L at 200C. Partially soluble, disperses.
Oil solubility: 12 g/L methanol at 200C. >380 g/L acetone at 200C.
Octanol:Water ratio: LogPow = -0.7 at pH 7 for iodosulfuron-methyl-sodium.
Soil organic carbon absorption coefficient: Koc = 0.8-152.
Vapour Pressure: Low. 6.7 x 10-9 mPa at 250C.
Vapour density:
Dissociation constant: pKa
Melting point: C.
Boiling point: C.
Molecular weight:
Bulk density: 710-820g/L
Specific gravity:
Viscosity: CPS.
pH: 8.9 at 1% solution in water.
Flammability: Non flammable. Combustible. Avoid build up of dust as a dust/air mixture can be explosive. No thermal decomposition until 3900C.
Flashpoint: C.
Autoignition: 378 degrees C.
Corrosivity: Non corrosive.
Shelf Life: Unlimited. Do not store for prolonged periods in direct sunlight.
(When Stored under Ideal Conditions)
32 SPILLS:
Sweep up granular product.
Absorb spills of product that has been mixed with water with earth, sand, clay or absorbent material such as vermiculite.
33 FIRE:
Avoid generation of dust clouds as a dust/air mixture can be explosive. Product is combustible but not flammable.
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:
Do not empty tank washings near trees.
Dry conditions will favour high carry-over of iodosulfuron to the following year and residual damage may occur to susceptible crops.
35 REFERENCES:
Acknowledgments:
Collated by HerbiGuide. For more information see www.herbiguide.com.au or phone 08 98444064.