Dock Control Project Update May 2019

Dock control in permanent pasture with and without clover.


Docks can cause high levels of competition in spring grazing fields as they respond well to nitrogen in a similar fashion to grass so when nitrogen is applied to boost early grass growth this can also see a big increase in the size of the docks in the field. Spraying is likely to be economic when docks cover at least 10% of the field area. To calculate the dock cover, count the number of docks in an area stretching 2.5m either side of you and 7m in front of you (35m2), as the number of docks in this area is equal to the percentage cover of docks .  The Farming Connect project at Newton farm is looking at the effectiveness and return on investment of different sprays to aid dock control.  We have measured the initial level of dock infestation which were above 20% infestation and have used different industry dock control treatments currently available.  On the fields that contain clover we will be using clover safe products.  We are comparing dock control in permanent grazing pastures which are used for rotational grazing on a total area of 15 ha with and without clover.  We will use a single spring application on most fields but will split the rate over spring and autumn on some fields to compare effectiveness.  Some fields on the farm containing docks won’t be treated and this will act as a control.  As an example on one of the fields (Cae Clover: 3.2Ha for a 8t DM/Ha ME 12.5) the improvement in grass available would equal 23 extra sheep/2 cows or 3T (aprox 1T DM/ha = £140.00/ha Pasture Profit Index Teagasc) extra grass in the field (Corteva Weed cost calculator).

April 19 assessed levels of dock in the fields to be treated: On initial assessment we measured between 10 – 20% dock cover.  On the 4th of April the docks were too small to be treated but by the beginning of May they were at the correct (rosette) stage for treatment.

After walking the fields with the farm agronomist we came up with a range of different treatments that would be used in this trial.  The plots and fields were sprayed between the end of April and beginning of May 2019.



Field Name

Field size




Cae Mawr (clover)


2,4-DB (400g/l) rate 73%

Amidosulfuron (75%w/w)

rate 67%:Crusade (drift reducer)


21 day harvest interval

5 Corner (clover)


Split field: 1/2 field

Amidosulfuron (75%w/w) 100%


½ field: 2,4-DB (400g/l) 73%

Amidosulfuron (75%w/w) 67%






21 day harvest interval

Cae Clover


Split field x 5 treatments

T1: Triclopyr (150g/l);Fluroxypyr (150g/l) (1/2 rate = full rate Doxstar)

T2:2,4-D (344g/l);Dicamba (120g/l) 71% + Fluroxypyr (200g/l) 50%

T3: Fluroxypyr (200g/l) 50%

T4: 2,4-D (344g/l);Dicamba (120g/l) 100%

T5: Triclopyr (150g/l);Fluroxypyr (150g/l) 50% + Triclopyr (200g/l);Clopyralid (200g/l)


T1: £22.00/ha



T2: £42.00/ha



T3: £12.35/ha

T4: £30.00/ha


T5: £50.00


HI: 7days

GP: 14 days






Dicamba – benchmark as an older product

Bridge Field


Triclopyr (150g/l);Fluroxypyr (150g/l) 50%


HI:7 GP:7

Sycamore (clover)


Amidosulfuron (75% w/w) 100%




We will be visiting the fields every 4 weeks to assess the dock control and using photographs to monitor die back and compare the effect of the different treatments and any effect there has been on any clover present.