Where docks are a problem in silage swards, it pays to control them before the silage is cut.
When it comes to choosing the most effective herbicide, there is nothing to beat Doxstar Pro.
Manufactured by Corteva Agriscience, Doxstar Pro contains two powerful chemicals – triclopyr and fluroxypyr – ensuring the most effective kill of the dock root system. Unlike dicamba-based products, it has the advantage of not causing any damage to grass growth.
Docks can devastate silage and grass swards. Even a moderate infestation will cut silage dry matter (DM) yield by at least 1t/ac.
Severe infestations can cut yields by up to a half.
The roots can be up to 1m deep, and a single mature dock produces up to 80,000 seeds. The seeds remain dormant in the soil for years, and germinate when conditions are suitable.
Timing is key in controlling docks
Weed control specialist, Chris Maughan, stressed that timing of the spray is the key to effective control of docks with Doxstar Pro.
“The ideal time to spray silage swards is two to four weeks after nitrogen (N) is applied, when docks are at the perfect stage for an effective kill,” he explained.
“The docks should then be actively growing, and be 15-25cm high or across, and before a seed head begins to appear.
“Wait a minimum of three weeks after Doxstar Pro is applied before cutting the silage. This ensures that the chemicals get fully translocated down to the root system, a vital factor in achieving long-term control,” said Chris, who is a technical manager with Whelehan Crop Protection, the distributor of Doxstar Pro on the Irish market.
Treatment of docks
Silage crops that were closed in recent weeks, and are targeted for cutting from mid-May onwards, should soon be approaching the ideal stage for treatment with Doxstar Pro.
“Killing the docks before silage is cut ensures higher yields and quality of silage, as well as a clean sward for grazing, or a second cut of silage,” Chris added.
“If docks are allowed to get too advanced for a pre-harvest application of Doxstar Pro, it is best to wait until the silage has been cut, and spray after about three weeks regrowth when the docks should be at the ideal stage for an effective kill.
“While this will involve forfeiting yield and quality of silage, it will ensure more effective long-term control of docks in the sward,” added Chris.
Problem of chickweed in some swards
Chris highlighted a growing problem of chickweed in silage and grazing pastures.
“Chickweed appears to be a particular problem in swards that were tightly grazed. This resulted in weed seeds being disturbed. These seeds germinated during the autumn and continued to grow during the relatively mild winter and spring,” he said.
“Doxstar Pro is highly effective on chickweed. It is also powerful on dandelions, which also appear to be a problem in many swards.”
Doxstar Pro for docks and weeds
- Contains two powerful chemicals, triclopyr and fluroxypyr;
- Powerful on docks and also highly effective on chickweed and dandelions;
- Apply at a rate of 2L/ha as a single application or two applications of 1L/ha six to 12 months apart;
- Best results are achieved when docks are actively growing, are 15-25cm high or across and before a seed head appears;
- Leave at least three weeks between spraying and silage harvesting;
- Use a minimum of 300L water/ha (30gal/ac);
- When using low drift nozzles, e.g. guardian air nozzles, water volume can be reduced to 200L/ha.
Pastor Trio gives wide control spectrum
Where a range of weeds such as chickweed, thistles, docks and buttercups are present in silage swards, Pastor Trio should be the herbicide of choice.
Another Corteva Agriscience product, it contains three active ingredients: Florasulam, fluroxypyr and clopyralid, ensuring a very wide spectrum of weed control.
As well as chickweed, thistles, docks and buttercups, it is also powerful on other weeds, including dandelions, daisies and plantain.
As with Doxstar Pro, timing of the spray is crucial. It should be applied two to four weeks after N is applied, and at least three weeks before the silage is cut, in order for the chemicals to be fully translocated to the root system of the weeds.
Docks should be actively growing and before a seed head begins to emerge, and thistles should have four to 10 leaves and be 15-25cm high.
Perfect for mouse-ear chickweed
Pastor Trio is also the perfect herbicide for mouse-ear chickweed, a problem in some recently sown new swards.
“Mouse-ear chickweed differs from common chickweed as it contains many tiny little hairs on the leaves. These hairs can prevent the spray droplets reaching the plant leaf cuticle.
“Because of its combination of active ingredients, Pastor Trio is particularly effective on mouse-ear chickweed,” said Chris.
Pastor Trio
- Contains three powerful ingredients: Florasulam, fluroxypyr and clopyralid;
- Weeds controlled include common chickweed; mouse-ear chickweed; docks; thistles; dandelions; buttercups; daisies; plantain;
- Apply to silage swards at 2L/ha in 200-300L water;
- Best results are achieved when weeds are actively growing and before a seed head appears;
- Leave at least three weeks between spraying and silage harvesting.
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