Herbicide products from Groups J and K are increasingly forming the basis of grass weed control programmes in Wheat and Barley. Boxer Gold and Sakura can be very effective tools for managing ryegrass and other grass weeds. However, at around $40/ha, the sustainability of a production system that is heavily reliant on these products in the absence of other integrated weed management tactics, is questionable.

These products vary in solubility and soil/stubble binding characteristics, which has implications for weed control and crop safety, as discussed below.

Both Group J and Group K products are likely to be most effective when used as part of an integrated weed management system, which includes non-selective herbicides and non-herbicide control measures. Using these products regularly under high weed pressure situations, will eventually lead to the development of herbicide resistance.

The table below shows products available in Group J and Group K, plus their key attributes. Specific comments are provided below:

* Rates vary according to crop and target weed registrations.

Sakura

Most suited to use in Wheat.
Less soluble than the S-Metolachlor component of Boxer Gold.
Lower solubility means that Sakura is less likely to wash back into the sowing row causing crop damage, compared to Boxer Gold.
Some root pruning can be observed on light textured soils.
Root pruning is exacerbated by late sowing into cold, wet soils.
Mixtures with Logran also exacerbate root pruning.
Requires more rainfall post-application for activation, which can lead to weed escapes when grasses germinate from deeper in the soil, or from sub-soil moisture.

Boxer Gold

Most suited to use in Barley.
Combination of two active ingredients provides both root and shoot uptake.
Can cause crop damage in Wheat and Barley where heavy rainfall washes the more soluble S-Metolachlor component back into the seeding row. This is more likely on lighter textured soils.
Registered for post-emergent suppression of 1-3 leaf ryegrass. This treatment requires rainfall directly after application and should not be seen as a primary tactic for ryegrass control.

Arcade / Countdown

Registered in Wheat and Barley.
The less soluble component of Boxer Gold.
Less likely to cause crop damage, but may be less effective for controlling grass weeds, especially those germinating in the seeder row.
Countdown only has a suppression registration at label rates of 2.5 L/ha.
Arcade registered for control of ryegrass at 3.0 L/ha.
Potential for mixtures with Dual Gold.

Dual Gold

Registered for suppression of ryegrass in Barley and Oats.
Registered in a range of crops for toadrush control.
Very effective against toadrush, even at 150 ml/ha rate.

Butisan

Registered for pre-emergent grass weed control in Canola.
Likely to provide control of both ryegrass and wild oats.
Not recommended to be used where Sakura is a principle ryegrass control measure in Wheat, due to the potential for developing resistance to both products.
Use in Canola would allow escapes to be controlled with post-emergent herbicide.
Recommended to be used in place of Trifluralin.
May be a potential solution for a specific, short-term grass problem.
Expensive.

Group J & Group K Herbicide Comparison