Duplosan KV

Registered until
Registration number
Active materials

A soluble concentrate formulation containing 600 g/l mecoprop-P (48.2% w/w) formulated as potassium salt.
A herbicide for the control of a wide range of broadleaved weeds, including Cleavers and Common chickweed, in winter and spring sown cereals and amenity grassland.

Controls many important weeds in cereals including Cleavers and Chickweed in a range of cereal crops.
- Works in cooler conditions.
- Flexible tank mix product.
- Control of Volunteer oilseed rape.
- Amenity grassland and managed amenity turf recommendation.
- An alternative mode of action to ALS acting products such as sulfonylureas.

PCS No. 02842
Pack size: 5 litres

Winter wheat, winter barley, winter oats
Maximum dose rate: 2.3 l/ha
Maximum total dose: 2.3 l/ha per crop
Latest time of application: Before third node detectable stage (GS 33)

Spring wheat, spring barley, spring oats
Maximum dose rate: 2.3 l/ha
Maximum total dose: 2.3 l/ha per crop
Latest time of application: Before third node detectable stage (GS 31)

Amenity grassland
Maximum dose rate: 2.3 l/ha
Maximum total dose: 4.6 l/ha per crop

Method of application: Tractor mounted / trailed sprayer
Other specific restriction:
- Applications to cereals must not be made between 1 October and 1 March.


IMPORTANT: This information is approved as part of the Product Label. All instructions within this section must be read carefully in order to obtain safe and successful use of this product.

DUPLOSAN KV is a hormone herbicide which is absorbed by both shoots and roots and rapidly translocated within herbaceous plants.

Apply as a MEDIUM spray as defined by BCPC. The best weed control will be achieved if crops are sprayed in conditions when weeds are actively growing, provided the crop is within the correct growth stages, see below. This is particularly important when DUPLOSAN KV is used in the spring to control large autumn germinated cleavers, which may have become ‘winter hardened’.

- Do not apply DUPLOSAN KV to any crop suffering from herbicide damage or physical stress.
- Do not apply DUPLOSAN KV during cold weather, periods of drought, if rain or frost are expected, nor if the crop is wet.
- The crop should not be rolled or harrowed within a period of seven days before or after spraying with DUPLOSAN KV.
- Avoid damage by spray drift on to susceptible crops such as beans, beet, brassicae (including oilseed rape), fruit crops, glasshouse crops, hops, lettuce, ornamentals, peas, potatoes, tomatoes and vines.
- WASH EQUIPMENT thoroughly immediately after use. Fill the tank with clean water and leave overnight. Spray out before storage or using other products. Traces of the product may cause damage to susceptible crops sprayed later.
- DUPLOSAN KV is not for use on Agricultural Grassland or Undersown crops.


Application rate: 1.5 l/ha
Susceptible: Common Chickweed, Fat Hen, Field Pennyccress

Application rate: 2.0 l/ha
Moderately susceptible: Corn Buttercup
Susceptible: Charlock, Cleavers, Common Mouse-ear, Black Mustard, Treacle Mustard, White Mustard, Small Nettle, Geater Plantain, Ribwort Plantain, Wild Radish, Shepherd’s Purse

Application rate: 2.3 l/ha
Susceptible: Volunteer Oilseed Rape,
Moderately susceptible:
Black Bindweed, Dove’s-foot Cranesbill, Red Deadnettle, Common Fumitory, Groundsel,Common Hempnettle, Knotgrass, Orache, Common Filed Speedwell, Ivy-leaved Speedwell, Wild Turnip.
Moderately resistant:
Cut-leaved Cranesbill,Scentless Mayweed, Black Nightshade, Pale Persicaria, Scarled Pimpernel, Common Poppy, Redshank, Viper’s Bugloss.
Top growth suppressed:
Creeping Buttercup, White Campion, Docks, Perennial Sowthistle, Smooth Sowthisle, Creeping Thistle.
Field Forget-me-not, Corn Marigold, Scented Mayweed.

Control of Chickweed at 1.5 l/ha rate in cereals due to the competitive nature of the cereal crop. Common chickweed will be controlled up to 15 cm diameter by DUPLOSAN KV at 2.3 l/ha. 2.3 l/ha is only to be used in amenity grassland.
Susceptible: controlled from cotyledon to two true leaf stage at 1.5 l/ha and 2.0 l/ha; controlled from cotyledon to six true leaf stage (or 5 cm across or high) by 2.3 l/ha.
Moderately susceptible: controlled from cotyledon up to two true leaves but only checked up to six true leaves or 5 cm across or high.
Moderately resistant: checked at cotyledon to two true leaves only.
Top growth suppressed when sprayed with 2.3 l/ha COMPITOX PLUS if appreciable foliage is present. Seedlings (cotyledon – two true leaves) will also be controlled.
Resistant: no useful effect.

Winter wheat, oats and barley
Dose 2.3 l/ha.
For autumn applications or in spring applied mixtures with specific herbicides (see mixtures section below), apply a maximum of 2.0 litres DUPLOSAN KV per hectare.
From one leaf stage in the autumn to before third node detectable stage. Spring application may follow autumn treatment.
Once tillering has begun, winter cereals become susceptible to damage from mecoprop-P until the leaf sheath erect stage is reached.
Late spraying: where spraying has been unavoidably delayed, DUPLOSAN KV may be applied up to and including the second node detectable stage. Applications at this timing may result in poorer weed control and also the optimum yield may not be achieved.
Do not use late applications of DUPLOSAN KV in mixture with more than one additional product, or where crops are potentially stressed from factors such as poor fertility, previous sprays or adverse weather conditions, e.g. frost, severe day/night temperature fluctuations or dry soils.
Autumn application of DUPLOSAN KV to control Common chickweed may not be fully effective under frost conditions which can reduce the efficiency of the chemical.
If sharp or severe frosts occur within three to four weeks of application to barley under stress or of low vigour on light soils, scorch or stunting may occur and yields may be less than optimum.

Spring wheat, oats and barley
Dose 2.3 l/ha.
From the first fully expanded leaf stage to before the first node detectable stage.

Amenity grassland
Dose 2.3 l/ha.
The sward should not be topped for at least a week before or after spraying. A maximum of two applications per year are permitted.
Allow to flower in July and then cut the flower stalks before seeding to weaken root reserves. Wait two weeks and then apply the recommended rate of DUPLOSAN KV. Docks will be severely checked but may recover, in which case the treatment should be repeated in the following season.
Common chickweed
Treat when actively growing and not shielded by grass, usually late summer or autumn.
If appreciable foliage is present there will be top growth suppression of weeds listed as ‘Top Growth Suppressed’ in the weed susceptibility table.

Water volume
Apply in 170–400 litres of water per hectare.
The lowest volume should only be used in open crops where weeds are small and where recommendations for any tank mix partner allow. As weeds become larger and/or crop cover increases, then the water volume should be increased. This is particularly important with cleavers. Once Cleavers are beyond the two whorl stage up to six whorls, a water volume of at least 330 litres of water per hectare should be used to ensure good coverage and control.

Half fill the spray tank with clean water and start the agitation. Pour in the required amount of DUPLOSAN KV. Add the remainder of the water and continue agitation until spraying is completed. This product may only be used in a tank mix or in sequence with other products when these uses comply with the label recommendations of every product in the tank mix/sequence. When tank mixes are to be used, each product should be added separately to the spray tank, taking due note of any instructions given as to the order of mixing.

Incompatible mixtures

DUPLOSAN KV is not compatible with trace element applications containing manganese sulphate.

When herbicides with the same mode of action are used repeatedly overseveral years in the same field, selection of resistant biotypes can take place. These can propogate and may become dominating. A weed species is considered to be resistant to a herbicide if it survives a correctly-applied treatment at the recommended dose. A strategy for preventing and managing such resistance should be adopted. This should include integrating herbicides with a programme of cultural control measures. Guidelines have been produced by the Weed Resistance action Group and copies are available from your distributor, crop advisor or product manufacturer.
DUPLOSAN KV is a registered trademark of Nufarm.

Registered for culturesRateBBCH
Winter wheat2.3 l0 - 33
Winter barley2.3 l0 - 33
Winter oats2.3 l0 - 33
Spring wheat2.3 l0 - 31
Spring barley2.3 l0 - 31
Spring oats2.3 l0 - 31
Grassland2.3 l0