The focus on early drilling this year is bound to put more emphasis on the need for effective residual stacking, according to Bob Mills, Technical Manager for Frontier Agriculture.

Last autumn many farmers used stale seedbeds almost circumstantially - crops were harvested, black-grass dormancy was low and there was a window of opportunity to apply one, two or in some cases three glyphosate applications before drilling, Bob says.

"The consequences were the best black-grass control we have had for a long time, but often at the expense of yield. The later drilled crops didn’t establish as well or tiller as profusely as the early drilled ones and the hard winter and dry spring really put these later drilled crops under pressure. It is clear to me that many growers are concerned about the possibility of this happening again – hence the enthusiasm to drill as early as possible this year," he says.

"Even though early drilling usually means better wheat performance, it also means that you are relying more on the pre-em herbicide treatment to rid the crop of competition. In addition this year ADAS are reporting high black-grass dormancy which means a longer more protracted germination period and so use of the most robust residual has become even more vital. A robust dose of Crystal mixed with at least 100 gms of diflufenican (Hurricane) will give an excellent start to the weed control programme, offering three different actives into the residual stack."

Pre-emergence for best results

Bob advises that the Crystal and DFF is applied pre-emergence for best results. "We have tried peri-emergence but over the years our experience indicates that a true pre-emergence timing evens out the vagaries of the season and gives the best results."

Having applied a robust pre-em herbicide treatment, he advises a follow-up in the autumn of Atlantis mixed with a residual Galivor which contains picolinafen and pendimethalin.  "This way you are applying a range of different active ingredients to the weeds and this gives you a better chance of effective control. It is also important to make sure the Atlantis treatment is applied in the autumn. The size of black-grass is critical to effective control, even more so than the weather conditions. Once the spring arrives, weeds are often too large for good control."

Bob Mills points out that he is a strong advocate of cultural control of grass-weeds but warns that "we can’t afford to have a repeat performance of last year. Black-grass is germinating slowly this year. This time last year we were already seeing a lawn of black-grass.  Effective residual stacking is vital for successful weed control this year."