Agronomist David Kirkham saw a useful step up in grass weed control and a real boost for broad-leaved weed control when he made the conscious decision to switch from Atlantis to Hamlet.
Advising farmers in Nottinghamshire and South Yorkshire, Mr Kirkham recommended Hamlet (mesosulfuron + iodosulfuron + diflufenican) last season on much of land that would ordinarily receive Atlantis (mesosulfuron + iodosulfuron) with pleasing results for him and his clients.
“Based on what I saw in the field, I think Hamlet gave a small, but useful improvement in black-grass control compared with Atlantis, and there was a similar improvement for rye-grass. It’s not a new herbicide that totally changes the situation but it certainly helps.”
The other bonus for Mr Kirkham was the additional broad-leaved weed control meant that additional broad-leaved weed herbicides were often unnecessary. “Hamlet did a good job against volunteer oilseed rape and cleavers in particular so that many farmers didn’t need to make a specific application for these weeds.”
Hamlet contains diflufenican which is important for boosting broad-leaved weed control but it may be a concern for farmers worried about the total diflufenican load in the soil. “This hasn’t been an issue for me,” says Mr Kirkham. “Hamlet was applied early and there was significant cultivation before this year’s oilseed rape went in – crops are up and away with no issue. Of course, it is important to watch how much DFF goes on at the pre-emergence timing so as not to take on any unnecessary risks.”
Mr Kirkham’s clients applied Hamlet from October through to January depending on the weed population. Generally, the early applied Hamlet was on fairly clean land where small grass weed populations needed tidying up. The later applied Hamlet was used on difficult black-grass populations after late drilling and robust pre-emergence herbicide stacks of Liberator (flufenacet + diflufenican) or Crystal (flufenacet + pendimethalin).
“We applied Hamlet throughout the autumn and winter if conditions allowed, as you would expect the earlier applications had slightly better control but there was a benefit at all application timings.”
Autumn 2016 was marked by a good late-drilling window and pre-emergence herbicide performance; however, Mr Kirkham is sure that Hamlet added to control. “I believe we got better control from using Hamlet. The pre-em helped but in May and June many fields still had plenty of black-grass and rye-grass plants in them and I could see the difference where Hamlet was used.”
Although it is a useful addition, Hamlet doesn’t change the fundamentals of black-grass control. “My clients drill as late as they dare – I don’t think there is much point drilling before the 20 October as what’s the use growing a field of black-grass.
“They recognise that black-grass is the single biggest threat to the sustainability of an arable farm. Yield monitors on combines might not be absolutely precise but they tell you that a clean patch yields 10 t/ha while an area infested with black-grass only yields 4 t/ha which is simply not profitable.”
Hamlet's activity against other grass weeds should also be factored in to decision making, he says. “Because we’ve been using Atlantis and now Hamlet against black-grass we don’t always consider the other grass weeds we’re controlling too. You might not realise that brome or wild oats are a problem on your farm unless you decide to skip the post-em.”
That’s not part of his strategy for black-grass control. He encourages his clients to take every possible step to reduce populations so that the yield monitor stays close to 10 t/ha which fully justifies the great lengths farmers now go to for black-grass control.