Don’t miss brome and ryegrass control in the autumn rush

In the race to get drilled-up this autumn, winter wheat growers who fail to instigate a robust grassweed control programme against bromes and ryegrasses risk jeopardising yields, warns Dow AgroSciences.

“A late harvest followed by wet conditions in many areas of the country has put pressure on those trying to get drilled-up in time before temperatures drop-off and ground becomes un-workable. However, cereal growers must focus on achieving solid brome and ryegrass control with a robust herbicide programme this autumn, if they are to avoid yield penalties in 2016,” says Stuart Jackson, Dow AgroSciences’ cereals herbicide expert.

Ryegrass in particular thrives in autumn sown crops and is highly competitive. Populations can build rapidly particularly where minimum tillage systems are used.

A residual pre-emergence application is an important first step in the herbicide programme, and for those opted out of stale seedbeds in the autumn rush, it’s vital.

“Treatments based on prosulfocarb or flufenacet plus pendimethalin are suitable for ryegrass control, but where bromes are the focus, treatments based on pendimethalin +/- flufenacet are most effective. Check spray records to ensure there hasn’t been a reliance on any one active ingredient over recent years. Ringing the changes on mode of action is good practice and important to delay the development of herbicide resistance to this vital chemistry,” advises Mr Jackson.


“Any areas of dense volunteer beans are likely to shade grassweeds from contact products. In these situations it is wise to remove them before the next step. Spitfire® (florasulam and fluroxypyr) is a good option for control.”

Finally, an application of a contact graminicide will control later-germinating grassweeds after residuals have run out of steam.

Broadway Star (pyroxsulam and florasulam) is one such product, and has the benefit of not only targeting grassweeds such as ryegrass, bromes and wild oats, but also a wide range of broad-leaved weeds including groundsel, cranesbill, volunteer rape and volunteer beans.

“Our trials and observations on farm have consistently demonstrated that autumn applications are more effective than treating in the spring, as weeds are smaller and soil temperatures provide optimum conditions for active growth,” says Mr Jackson.

“In fields where there is a known high population of brome or ryegrass, our advice is to ensure a robust pre-emergence herbicide is applied, and prioritise these fields for autumn treatments with a contact herbicide.

“However, if conditions don’t allow autumn applications, good results can still be achieved with spring applications provided treatments are made no later than GS29 of ryegrass and GS24 of brome, during periods of active growth.”