Power-up Grassweed Control with a Stack of Herbicide Actives

Stack and sequence 

The best practice and most robust advice when it comes to tackling weeds such as black-grass, ryegrass and brome is to delay drilling until well into October. However, given the impact that two wet autumns have had on the ability to travel on waterlogged soils, it is understandable that a significant number of growers have been unwilling to wait this year, with drilling already underway in most parts of the UK. 

Where crops have been drilled early, a strong stack and sequence of herbicide active ingredients will be needed to provide satisfactory levels of weed control. That’s especially important in those parts of the country where a potential lack of soil moisture could have a detrimental impact on residual herbicide activity.  

Protecting new actives 

New active ingredients such as aclonifen or cinmethylin will be essential at the pre-emergence timing to prevent black-grass and ryegrass from stealing a march on early drilled crops. However, despite their improved efficacy, even these new herbicides will also require additional help to maintain weed control further into the crop establishment and early development phases 

Growers are therefore advised to ‘power-up’ their herbicide programmes by incorporating additional active ingredients from different mode of action groups, with diflufenican, pendimethalin and chlorotoluron all providing additional, cost-effective weed control. 

Herbicide programmes 

For example, a programme which starts with a foundation application of aclonifen, diflufenican and flufenacet at the pre-emergence timing will be enhanced by the addition of ANTHEM^® (400 g/l pendimethalin) at the same timing, or by a post-emergence treatment of TOWER^® (250 g/l chlorotoluron, 40 g/l diflufenican & 300 g/l pendimethalin). 

^{ANTHEM’s SC formulation outperforms standard CS formulations of pendimethalin when used as a tank mix partner to control black-grass} 

Similarly, where a foundation application of cinmethylin and pendimethalin is being used, the addition of HURRICANE^® (500 g/l diflufenican) will help to power-up the pre-emergence treatment. This could then be followed by a post-emergence application of TOWER^® or OMAHA^® 2 (40 g/l diflufenican & 400 g/l pendimethalin) to extend the window of weed control. 

^{The addition of diflufenican also improves the control of flufenacet resistant ryegrass…} 

^{…with a clear reduction in the number of ryegrass heads when diflufenican was added to the tank mix.} 

For the most difficult populations of grassweeds, experience suggests that the addition of flufenacet or prosulfocarb can also be beneficial against black-grass and ryegrass respectively when included in an early post-emergence sequence. In these situations, a black-grass programme may include TOWER^® or OMAHA^® 2 plus flufenacet at the post-emergence timing, or TOWER^® plus prosulfocarb where ryegrass is being targeted. 

Using additional actives, either as tank mix partners or to extend the herbicide sequence, will also help to delay the development of weeds becoming resistant to new actives. 

 ^{Blackgrass pressure is high when crops are drilled early, so apply a stack and sequence of herbicides to ensure protection}

ANTHEM^® is ADAMA’s SC formulation of pendimethalin (400 g/l). It delivers higher efficacy on grass weeds compared to CS preparations of the same active ingredient, is user-friendly thanks to its easy to pour and rinse formula and provides long-lasting and reliable residual herbicide activity against tough grass and broad-leaved weeds in cereals.

TOWER^® is an exclusive co-formulation of three active ingredients (250 g/l chlorotoluron, 40 g/l diflufenican and 300 g/l pendimethalin) all of which have complementary modes of action for optimal grass weed control and resistance management. In addition to providing excellent control of annual meadow grass and broadleaved weeds, TOWER also provides good activity against grass weeds in winter and spring wheat, winter and spring barley, winter rye and winter triticale. 

HURRICANE^® SC is a residual herbicide for use in cereals to control a broad spectrum of broadleaved weeds. Containing 500 g/l diflufenican, HURRICANE provides a proven additive benefit in black-grass programmes and contributes towards annual meadowgrass control when used in conjunction with partner products.

OMAHA^® 2 is a broad-spectrum residual herbicide for the control of grass and broadleaved weeds in winter and spring cereals. Containing 40 g/l diflufenican and 400 g/l pendimethalin) it is also a useful tank mix partner for black-grass and wild oat control.