Corteva Agriscience’s low odour, low volatility Colex-D herbicide has been approved by the APVMA for use in winter cereals, pastures and non-agricultural areas, giving growers confidence they can use the new 2,4-D formulation without the risk of spray drift.
Colex-D is a next-generation herbicide with patented technology offering the performance and efficacy of traditional 2,4-D products, but contains drift reduction technology (DRT) with near-zero volatility, to prevent damage to neighbouring crops.
Off-target movement from 2,4-D applications can occur through physical drift, when sprayed droplets move with the wind and settle on sensitive crops, or volatility, where droplets can volatilise (move) off the crop or soil surface, re-enter the atmosphere and affect crops that may be kilometres away from the treated paddock.
The formulation and APVMA approval of the new Colex-D herbicide makes it a far superior choice for mixed enterprise growers, according to Corteva Agriscience senior biologist Greg Wells.
“Every year we see crop damage in neighbours’ fields from off-target movement of traditional 2,4-D products, particularly in sensitive species such as cotton in summer, vines in spring and canola or pulse legumes in late winter,” Greg says.
“Colex-D is the least likely 2,4-D formulation to cause off-target damage due to its unique chemistry that uses 2,4-D choline, which makes the product far less likely to disassociate from the acid and gives it a near zero volatility profile,” he adds.
“As well as addressing physical drift and volatility, this change in chemistry gives Colex-D an ultra-low odour when compared to traditional 2,4-D products, eliminating the three key problems caused by the older chemistry.”
Advances in 2,4-D formulations over recent years have addressed some of the physical drift issues through adding new ingredients to the product or the spray tank, but the nature and form of the active ingredient is what drives the volatility of the products.
When mixed with water and applied, amine and ester forms of 2,4-D can release volatile forms of 2,4-D acid, which is more likely to volatilise off soil, stubble or treated plant surfaces after application.
2,4-D amine formulations have the potential to cause crop injury from volatility, and ester formulations are likely to be three to four times more volatile than amine formulations.
The proprietary ingredient built into Colex-D significantly reduces the driftable portion of the spray droplets during application, reducing the amount of extremely fine, very fine and fine droplets (by 100 per cent, 63 per cent and 26 per cent respectively in testing), which have the potential to physically drift during application, when compared to commonly used 2,4-D amine formulations.
“Growers need to do everything they can to minimise the risk of damage caused by physical drift and the more subtle movement of volatile 2,4-D formulations, and the Colex-D formulation allows broadacre growers to access robust weed control of 2,4-D, with greatly reduced risk of harm,” Greg says.
“When used in accordance with the label directions and following industry spraying guidelines, the built-in Drift Reduction Technology, near-zero volatility and ultra-low odour means Colex-D is a 2,4-D that you can apply with confidence and be a better neighbour,” he says.
For the latest label, more technical information and specific spray guidelines for Colex-D, go to corteva.com.au or contact your local territory account manager.
