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Thidiazuron 500


APVMA Code :58421

Active Constituent(s): 500g/L thidiazuron
Registered For:

 Commercial use

 Domestic use

Overview: For the defoliation of cotton prior to harvest.

Chemical Group substituted urea


 SDS (284.9 KB)

 Label (1.7 MB)

General Instructions


Cheminova THIDIAZURON 500 is an odourless, non-corrosive defoliant/harvest aid. After treatment, leaves fall while still green so that there is minimal dry leaf trash to contaminate fibre or interfere with harvesting. Maximum defoliation occurs 7 to 21 days following application. Good control of regrowth is seen when this product is used at rates over 100mL/ha. Defoliation will be slower under average conditions, or when the crop is not physiologically mature.



Rainfall within 24 hours after application will reduce the effectiveness of this product. Re-treatment may be necessary.


Defoliation of crops with moderate to high levels of nitrogen remaining in the soil are more prone to leaf freezing than crops that have depleted soil nitrogen.


Tank mixes with organophosphates may form a residue in application equipment. While still fresh and moist, this residue is easily removed by flushing the entire system with a commercial tank cleaner.


Do NOT allow the spray solution to dry in the application equipment. Immediately following application, flush and rinse equipment (mix tanks, pumps, transfer lines, application tanks, sumps, booms, nozzles and all related equipment) thoroughly with detergent and water.


Should any residue of this product remain in the sprayer system, it may be released during subsequent applications of other products causing damage to crops.


Export Of Treated Produce

Growers should note that suitable MRLs or import tolerances may not be established in all markets for produce treated with this product. If you are growing produce for export, please check with Cheminova for the latest information on MRLs and import tolerances BEFORE using Cheminova THIDIAZURON 500.




Add the required amount of product straight into the partly filled spray tank or mixing vat with agitator running, followed by Ampol D-C-TRON Cotton Spray Oil, then add the rest of the water. Keep mixture agitated while spraying.


Use only freshly prepared sprays. Do NOT store spray mixture overnight. When tank mixing with emulsifiable concentrates (EC), add Cheminova THIDIAZURON 500 to the 3/4 filled spray tank or mixing vat and agitate thoroughly. With agitator running, then add the EC product, followed by the Ampol D-C-TRON Cotton Spray Oil. Keep mixture agitated while spraying.




Apply as a uniform spray ensuring thorough coverage of the whole plant.





Apply by aircraft in 20 to 40 L/ha spray mixture and ensure thorough coverage. A steady cross wind is recommended for best penetration. Do not exaggerate swath width.



Standard boom sprays are recommended and must be fitted with mechanical or by-pass agitation. Use sufficient water to obtain complete coverage of all leaves, ie at least 90 to 100L water/ha. Good coverage should be obtained with 3 or more nozzles per row depending upon crop height and canopy density. A nozzle configuration including droppers will give maximum coverage in dryland crops with particular care being taken to ensure thorough but even coverage. Overdosing on some plant parts, eg. nozzle overlap along the sides of plants may cause localised leaf freezing. If band spraying dryland crops, care should be taken when calculating the actual applied rate of product per sprayed hectare.



Cheminova THIDIAZURON 500 is compatible in tank mixtures with ethephon, dimethoate and parathion.


Caution: When tank mixed with Roundup CT (glyphosate), a higher proportion of cotton leaf may be retained (freezing). Do not use this mixture on stressed cotton, particularly drought affected cotton.




DO NOT apply when night temperatures fall below 12.


DO NOT apply following application of sodium chlorate, magnesium chlorate or diquat.


Protection of crop, native and other non-target plants

DO NOT allow spray to drift or to contact trees or crops other than cotton, as this product may injure or defoliate other crops, particularly citrus, grapevines and lettuce.


To help reduce drift damage potential:

  • DO NOT apply by air when citrus in flush is within 8 km downwind from the point of application.
  • DO NOT apply by air when within 800m of lettuce.

In addition:

  • DO NOT plant lettuce or carrots in cotton fields where this product has been applied within the previous 9 months.
  • DO NOT plant legumes, lucerne, other root crops or leafy vegetables (besides those noted above) in cotton fields where this product has been applied within the previous two months.
  • DO NOT plant small grains, sorghum or corn in cotton fields where this product has been applied within the previous two weeks.

Safety Directions


May irritate the eyes. Avoid contact with eyes. When opening the container and preparing spray, wear cotton overalls buttoned to the neck and wrist (or equivalent clothing) and elbow length PVC gloves. After each day's use, wash gloves and contaminated clothing. Wash hands after use.



Keep out of reach of children. Store in the closed, original container in a dry, cool, well-ventilated area out of direct sunlight.



Triple or preferably pressure rinse containers before disposal. Add rinsings to spray tank. Do not dispose of undiluted chemicals on site. If recycling, replace cap and return clean containers to recycler or designated collection point.

If not recycling, break, crush, or puncture and bury empty containers in a local authority landfill. If no landfill is available, bury the containers below 500 mm in a disposal pit specifically marked and set up for this purpose clear of waterways, desirable vegetation and tree roots. Empty containers and product should not be burnt.





Do not use human flagging unless flaggers are protected by engineering controls such as vehicles with cabs.


Re-entry Period

Do not allow entry into treated areas until spray has dried. When prior entry is necessary, wear cotton overalls buttoned to the neck and wrist (or equivalent clothing) and chemical resistant gloves. Clothing must be laundered after each day's use.


Product details last updated on 10 Nov 2006


DISCLAIMER: This is not the THIDIAZURON 500 label. To view or print the label for this product, click the "MSDS/Label" tab at the top of this page. Always follow label instructions.


For specialist advice in an EMERGENCY only phone 1800 033 111, TOLL-FREE, ALL-HOURS, NATIONWIDE

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