Pendimethalin has been a cornerstone of weed control strategies for a number of years in the UK with the broadest weed spectrum as well as label and off-label crops uses, according to BASF.
It also has a key role to play in the control of ALS-resistant black-grass and it is one of the few non-ALS herbicides which control both sensitive and resistant poppy, making it vital for future resistance management strategies for broad-leaved weeds, and particularly poppy control, says Sarah Mountford-Smith of BASF.
“However despite pendimethalin being the cornerstone of weed control strategies on many farms in the UK, the intense yellow staining has been a bug bear for years. It is fair to say a lot of users have just put up with this yellow staining. In 2011 BASF introduced a non-staining version of pendimethalin, Stomp Aqua, making this highly effective active ingredient much easier to use. We have found that farmers across the UK have really like the new formulation, with sales of Stomp Aqua going from strength to strength,” says Sarah.
Chris and Ian Cockayne have used pendimethalin in one form or another for many years, but were advised by their distributor agronomist to try out Stomp Aqua “when it first came out.”
Chris and Ian farm 700 acres in Cropwell Butler in Nottinghamshire and grow winter wheat, oilseed rape, sugar beet and spring barley for seed. They also host the local NIAB oilseed rape trials. Their most challenging weeds on the farm are black-grass, annual meadow-grass, mayweed, knotgrass and crane’s-bill.
Chris and Ian see Stomp Aqua as “a good residual active product with a good broad-leaved weed spectrum and some useful grass-weed activity on meadow-grass and black-grass. It is a good all-round herbicide.”
Ian said that they were particularly unhappy about the strong yellow colour and staining of the original pendimethalin formulations. “The main benefit we have seen once we have changed to Stomp Aqua is the lack of staining. It looks to be a nice formulation to use, too and it doesn’t smell like the older formulations. So we have a herbicide with the benefit of less staining but one that is just as effective in terms of results. We wouldn’t go back to the other staining pendimethalins now.”
Farming in Ramsey in Cambridgeshire, Paul Drinkwater uses Stomp Aqua as the first building block for weed control on his farm and often tank mixes it with other grass-weed herbicides such as Atlantis and Horus, both of which must have a suitable residual partner.
It is unsurprising that black-grass is top of Paul’s weed hit list. Other challenging weeds on his farm in Ramsey, Cambridgeshire include mayweeds, crane’s-bill, cleavers and other broad-leaved weeds.
He has used the older pendimethalin formulations in the past. “It was horrible stuff. I was fed up with the EC formulation, so I decided to change to a new cleaner formulation which was Stomp Aqua. Stomp Aqua causes very little staining – the sprayer and all its hosepipes stay the colour they were originally designed to be! I am not sure if I would ever go back to the older formulation, even if it were much cheaper.”
“I also like the new packaging for Stomp Aqua – it is much easier to get the herbicide out of the can, with no glugging or spilling. The new cans have no foil seals, so opening is a lot easier and it appears to be easier and quicker to pour. I am sure that any spray operators would find it much easier, safer and quicker to handle. The non-staining benefit will also appeal to spray operators. All in all, Stomp Aqua is much easier for operators and leads to more efficient spraying.”
