The continuing fluctuations in daytime and night-time temperatures will affect the growth of Docks. Translocated herbicides need perennial weeds to be actively growing to ensure that the chemical can get down to the roots of the weeds to achieve optimum control. This is an important factor for Corteva Grassland Herbicides, so that they can kill right down to the roots.
Docks affected by cold temperatures will typically have thicker, waxy leaves with purple tinges. Leaf area can be quite small.
Docks showing active growth will be a more vibrant green and less waxy. For optimal control wait until overnight frosts / cold nights have passed and sustained active growth has begun
If the docks planned for treatment are in cutting leys ensure you allow a minimum of 3 weeks post treatment and before cutting to get optimal translocation and biomass reduction.
If cutting is likely to be soon then consider delaying treatment until after the first cut. Allow 2-3 weeks for docks to regrow before spraying.
Finally, remember that when treating weeds in these conditions (fluctuating temperatures and grass stress, possibly due to low rainfall levels) there is an increased risk of grass damage, so don’t rush to control docks just yet.