Selecting the correct herbicide programme and good application practice is key to control of problem weeds and protecting chemistry for the future.
Using phenoxy and suphonylurea (SU) herbicides alongside each other is helping
to tackle herbicide resistance in the latter group.
Nufarm agronomy lead Dan Macdonald says for the last 20 years there has been heavy reliance on SUs.
He says: “They did what it said on the tin, giving good weed control, flexible application timing and were a flexible tank mix partner.
“But because we have relied on them so heavily in the last 20 years, there is resistance to
this type of chemistry in broad-leaved weeds.
“Confirmed cases of broad-leaved weed resistance are increasing year-on-year where weed control has relied upon the use of sulphonylureas.
“In chickweed, mayweed and poppies, we are seeing either no control or reduced control.
“It depends on where you are in the country. We are seeing resistant chickweed in Scotland, whereas in East Anglia it tends to be poppy.
“Farmers need to control these weeds and phenoxies can play a part in this. There is no known resistance to phenoxy chemistry – it has a unique mode of action.
“I am not saying you should switch over 100% to phenoxies – SUs and phenoxies can complement each other.”
“A programme which combines phenoxies with sulphonylureas in tank mixes can deliver control of a wide spectrum of broad-leaved weeds.
“Adding fluroxypyr or florasulam to the mix, for example, gives an added effect
of cleaver control.”
Combining an SU and phenoxy protects both chemistries and does not rely on one mode of action. It is also a good value option compared with other products on the market, he adds.
At last year’s CropTec Show, Nufarm published Rediscover Phenoxies – a Guide to Phenoxy Herbicides.
It was designed as a re-education guide for growers and agronomists on using phenoxies, including a description of their mode of action and which products control particular weeds. It will also be available at this year’s CropTec Show and can be found on Nufarm’s website.
“We have certainly seen more uptake of phenoxy products from a sales point of view,” Mr Macdonald says.
“Over the spring season we were receiving more calls about problem weeds and which phenoxy will control them.”
For this year’s CropTec Show, Nufarm is putting together an agronomy solutions guide which is more product specific, including the whole Nufarm product range, now bolstered with a variety of SU herbicides, not just phenoxies, and graminicide Fusilade Max (fluazifop).
“It will be designed as a farming year calendar, starting with August when oilseed rape is planted and going right through the cropping year including winter cereals, then spring cereals,” Mr Macdonald says.
Nufarm is also hoping to launch SprayWise in 2019/20. SprayWise is an innovative programme intended to provide beneficial tools and information for sprayer operators, growers and agronomists looking to get the most out of their spray applications.
The SprayWise programme is already meeting with success in Australia and, Nufarm UK is looking to build upon this success by adapting its principles to suit UK conditions.
The UK version of SprayWise will feature a video showing how growers can achieve better product application and use, explains Mr Macdonald.
“It will show best sprayer filling practice to avoid point source contamination of water courses,” he says.
The video will include information on taking products into store, chemical store layout, emptying cans into the sprayer and rinsing empty cans. They will also cover best practice in the field.
Nufarm is also collaborating with BASF, Corteva Agriscience, Nufarm and Syngenta to promote closed transfer system technology known as the easyconnect system, which aims to reduce point source contamination and operator exposure to chemicals.