Tank Mixing Glyphosate & Trifluralin

In Southern NSW there is a rapidly increasing level of Glyphosate resistance, but there is still a relatively low level of resistance to Trifluralin.

Glyphosate and Trifluralin are sometimes mixed to save time during sowing, but this results in a compromise of one or both products.  Glyphosate requires time to be absorbed into the plant and translocated throughout the plant, while Trifluralin requires rapid soil incorporation to minimise losses.  While mixing the two does save time, the potential reduction in weed control can be very costly in the long term.

Rather than focusing on short term gains, it would be wise to try and prolong the life of both products by using them in such a way that their effectiveness is maximized.

Where large weeds are present, Glyphosate should be applied separately and prior to Trifluralin. In this situation, mixing Paraquat with Trifluralin for a double knock is a good practice.  For small, newly emerging weeds, a tank mix of Paraquat and Trifluralin may be satisfactory.

Managing all weeds, but especially herbicide resistant weeds is a numbers game. It would be prudent to learn from the mistakes of farmers in other areas of the world, by striving to prolong the life of the remaining herbicides for as long as possible.  This is achieved by using them in the most effective manner possible.