Tordon, celebrating 50 years of powerful weed control

First registered more than fifty years ago, and through various name and packaging evolutions, the Tordon™ range of herbicides remain a key component to any land managers’ woody weed management programme. It is a tried and trusted brand with products today including Access™, Grazon™ Extra, Tordon 75-D, Tordon Granules and Tordon RegrowthMaster.

Tordon 50-D was the first product registered in the late 1960’s for the control of eucalypt regrowth by stem injection application. “I remember my father using this product when I was a kid”, said Dow AgroSciences Woody Weeds Technical Specialist, Chris Love. “Dad used to drag me along to cut off the cypress pine while he would treat the eucalypt regrowth – it was great to go back 12 months later and see the grass response and happy cows.”

Tordon 75-D was then developed and is still registered today for the control of a wide range of annual broadleaf weeds in winter and summer cereals, control of fleabane in fallow, control of sicklepod in sugar cane (QLD only) as well as a range of perennial weeds in agricultural non-crop areas. “With 75 g/L picloram and 300 g/L 2,4-D this powerful combination is a core component of residual fallow weed control in northern NSW and southern Qld” said Mr Love.

Tordon 50-D evolved into Tordon 105, then by the mid-1980s Tordon TCH was launched. “Tordon TCH was the first step away from 2,4-5T based products” advised Mr Love, who joined Dow Chemical around this time as a research agronomist. Then in 1999, DowElanco launched Tordon DSH.

Today, Tordon RegrowthMaster is the updated management tool to assist graziers in thinning regrowth to improve productivity of grazing enterprises and assist with native forest management. Containing 200 g/L triclopyr, 100 g/L picloram and 25 g/L aminopyralid, Tordon RegrowthMaster can be used via stem injection or cut stump/brushcutter application as well as control of harrisia cactus by foliar spray treatment.

Tordon RegrowthMaster delivers better control of wattle regrowth than the old Tordon DSH with significantly less root suckering in species where that is common. “The grass response is still the same with the bonus of selective control of unwanted woody weeds in native forestry situations” said Mr Love.

Access Herbicide evolved from Tordon 1040 in the early 1990s. Access is registered for the selective control of woody and noxious weeds by basal bark, ThinLine and cut stump application techniques. “If you can’t control a small woody species with Access by basal bark application, then nothing will”, says Mr Love. “Access can be used anytime, anywhere with great results”.

Another handy option is Tordon Granules, which does not require spraying equipment and can be conveniently applied by hand as and when required. Applied as a granule, there is no risk of spray drift.

The most recognizable Dow AgroSciences brand today, Grazon Extra, evolved from Tordon 520, then Grazon FSH, then Grazon DS before Grazon Extra was launched in 2008. Grazon Extra is the premium brand for the control of blackberry, gorse, St John’s wort, lantana and many other other hard to kill woody weeds by foliar spray application. “It is the best there is – with the addition of aminopyralid, the best got even better” pronounced Mr Love.

With labour comprising around 65% of the costs involved in managing woody weeds, it’s critical to get the most powerful chemistry to ensure the job is done well the first time. The Tordon range has fifty successful years behind it and a world of possibilities in the future.