ProForce Duke Herbicide.

ProForce Duke herbicide is a powerful selective herbicide made specifically for turf grass. This product from Indigo Specialty, is an alternative to Destiny herbicide, and contains iodosulfuron-methyl. This means you get the same great results and save money.

It controls many tough to control weeds that other chemicals can’t handle. These include Winter Grass, Onion Grass and ryegrass.

Key Facts About Duke Herbicide.

• Active: It contains 100 g/Kg of Iodosulfuron-methyl.
• Chemical Group: It is a sulfonylurea herbicide and is in FRAC Group 2. This group also contains ProForce Recondo and Envu Tribute.
• Type: Duke is a selective post emergent herbicide.
• It is an alternative to Destiny herbicide.
• Pack Size: Available in 100 g and 500 g packs.
• Safety: Safe on most grass varieties.

This free herbicide resistance chart will help you with a resistance management strategy with Duke.

Table of Group 2 Turf Herbicides.

How Does Duke Herbicide Work?

ProForce Duke stops a key enzyme in weeds. This enzyme is called acetolactate synthase (ALS). Plants need this enzyme to produce important amino acids.

When Duke Herbicide blocks this enzyme, weeds can’t grow properly and they die. This takes 2-3 weeks to see the full results. Duke is slow acting but very effective. You need to be patient at let it work.

Two Key Uses for Duke Herbicide.

Duke excels in three areas:

• As a transition aid to remove ryegrass out of warm season turf like Couch.
• To control Onion Grass.
• You can safely use this on Kikuyu grass.

Duke Herbicide for Transition.

What is Ryegrass Transition?

Ryegrass transition is when you remove temporary ryegrass from couch. This happens every Spring when:

• Ryegrass starts to compete with couch coming to of Winter dormancy.
• You want couch to dominate the grass cover over the Summer.

Why Transition Matters:

• Ryegrass competes with couch for nutrients, light and space.
• A mix of grass types looks patchy and uneven.
• In sports grounds over the Summer couch can cope with wear better.
• In the Summer heat ryegrass weakens, and can leave bare patches.

Why Use Duke Herbicide to Transition?

Duke herbicide is uniquely effective for ryegrass transition because:

Selective:

Duke herbicide kills ryegrass but is completely safe on couch. This selectivity is crucial to enable a smooth transition.

Perfect Timing:

• Apply Duke in the early Spring once temperatures start to increase. This is because:
• The ryegrass is still actively growing.
• The couch is starting to break dormancy.
• Weather conditions favour the activity of this herbicide.

Clean Results:

Duke herbicide gives:

• The complete removal of the ryegrass.
• No damage to the couch grass.
• A very smooth Smooth transition without any bare patches.
• Professional results.

When to Apply Duke Herbicide for Transition.

The ideal Window:

• Between August to October in most Australian regions.
• When the soil temperature is 12-15°C.
• Before the couch becomes fully active.
• While the ryegrass is still green and growing.

When to Transition:

• You start to see couch shoots.
• The ryegrass is still actively growing.
• The daytime temperatures are consistently above 18°C.
• 6 to 8 weeks before the peak of Summer.

Regional Timing Guide:

Northern Australia: July-August.
Central Australia: August-September.
Southern Australia: September-October.
Cool areas: October-November.

Duke Herbicide Transition Success.

Professional turf managers report great results when they use this to transition out ryegrass:

• It removes 95-100% of the ryegrass when applied correctly.
• Zero couch damage at the recommended rates.
• A clean transition in 3 to 4 weeks.

Transition Protocol.

One to two weeks before you plan to transition:

• Feed the couch to encourage it.
• Reduce the height of cut gradually.
• Make sure that there is adequate soil moisture.
• Check the weather forecast.

When you apply:

• Use Duke herbicide at 100-125 g/Ha.
• Add a non-ionic surfactant at 0.25 %. We suggest Optispread. Do not use a spray buffer. Duke works best at a water pH of around 7.
• Apply it in calm, mild conditions.
• Ensure you get even coverage.
• You can mix it with Vertmax Duo turf pigment and Vertmax pigment to retain heat and give a quicker result.

Post-Application. Two to Four weeks after use.

• Due to it being “sticky” Duke Herbicide can leave a residual in a spray tank. We recommend the use of Tank Aid to clean any residual out of the tank.
• Avoid any heavy traffic.
• Continue regular watering.
• Don’t fertilise for 2 weeks.
• Monitor the couch emergence.

Follow-up Care.

• Fertilise normally after 4 weeks
• Gradually return to usual height of cut.
• Overseed any thin areas if you need to.

Duke Herbicide vs Onion Grass.

Why Onion Grass is So Hard to Kill?

Onion grass (also called Guildford grass) is one of the toughest weeds to control in turf. This weed has several features that make it hard to control:

• A deep root system.
• It has waxy leaves, that repel most herbicides.
• It is active over the Winter when grass is dormant.
• This weed spreads fast.

How Duke Beats Onion Grass.

Duke is very effective against Onion Grass. Here’s why it works so well:

Systemic Action:

• Duke moves through the whole plant. This includes the roots and bulbs, and kills the Onion Grass completely.

Perfect Timing:

• Onion grass emerges in the Autumn and then grows through the Spring. This matches perfectly with the usage timing for Duke herbicide.

Selective Control:

• Duke kills Onion Grass without any damage to couch, kikuyu, or most buffalo varieties.

Long-lasting Results:

One application can control Onion Grass for the entire season when you use it correctly.

Duke Success on Onion Grass.

Many users report 100% control of onion grass with Duke herbicide. The key is:

• Use this when the Onion Grass is actively growing
• Use the correct rate for your turf type.
• Add a surfactant for better uptake. We suggest Optispread.
• Be patient for 2 to 3 weeks to see the full results.

What Weeds Does Duke Herbicide Control?

Duke herbicide controls a wide range of problem weeds in turf:

Broadleaf Weeds:

• Bindii. A painful lawn weed with spiky seeds.
• Black Thistle. A tough perennial weed.
• Cat’s Ear. A dandelion-like weed.
• Cotula. A small daisy-like weed.
• Cudweed. This is a grey-green Winter weed.
• Medic. This looks like clover.
• Mouse Ear Chickweed. This forms thick mats that choke out turf.
• Oxalis.
• White Clover. A common lawn weed.

Grass Weeds:

• Ryegrass. This gives excellent control against this, and is ideal for transition from couch.
• Guildford Grass (Onion Grass). A main target weed
• Winter grass. Duke only suppresses this
• Bahia Grass. This only suppresses and reduces the amount of seedhead.

How Safe is Duke Herbicide on Turf?

Safe Grass Types:

• Couch Grass (Common and Hybrid) – Very safe
• Kikuyu Grass – Very safe
• Buffalo Grass – Safe on most varieties
• Zoysia – Generally safe (check the label).

Grass Types to Avoid:

• Queensland Blue Couch – DO NOT USE.

If you have questions or concerns about the use of Duke herbicide, please feel free to contact a sports turf consultant or turf agronomist.

Duke herbicide Label

Duke SDS