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Closed mixing and loading systems for paraquat

16 July 2018

Using a closed mixing and loading systemUsing a closed mixing and loading system Paraquat is a vital tool for farmers facing the spread of glyphosate resistant weeds and limited in the options they have for total vegetation control.

No-till and other conservation tillage systems, which promote soil health and fertility, and help to prevent soil erosion, rely on non-selective herbicides. The broad spectrum of weeds controlled by paraquat, its unsurpassed speed of action and rainfastness, with no restrictions on plantback crops are key benefits.

New EPA safety requirements

Like all pesticides, paraquat must be handled carefully when filling spraying equipment. The US Environmental Protection Agency (EPA) has stated that it will impose more stringent measures to further protect farm workers and others from accidental exposure to undiluted paraquat herbicides.1 Already, paraquat herbicides can only be applied in the US by certified applicators and there will be mandatory special training emphasizing the new rules on handling. Revised product labels and new certification requirements will be in place in 2019. A further measure will be implemented in 2020. This will mean that paraquat products must be sold in packs that can only be used in closed mixing and loading systems.

Closed systems allow a concentrated product to be pumped via lockable couplings and hoses joining the product container to the spray tank. The whole operation of filling a sprayer ready for fieldwork is, therefore, achieved in a closed system minimizing the potential for exposure to the pesticide concentrate. The pack seals in the system also safeguard against the illegal decanting of product into another container.

Other advantages

Apart from safety considerations, there are economic and environmental advantages from using closed systems. These come from the controlled delivery of the required volume of product – avoiding spills and adding the correct amount. In addition, such systems are well suited to dealing with large drums. This means less packaging, transport and storage economies, and easier recycling.

A video demonstrating the use of a closed mixing and loading system can be watched here.


1. EPA press release, 15 December 2016.


The brand name of the leading paraquat product is GRAMOXONE®. The high concentration product available in Australia is GRAMOXONE® 360 PRO.

GRAMOXONE® is a Registered Trademark of a Syngenta Group Company.