01 March 2022
Agronomists urge growers to be flexible and put crop safety at the forefront of potato weed control strategies
HIGHER fertiliser costs, price pressure from discount supermarkets, the potential loss of more key actives in the crop, plus issues around maximum residue levels (MRLs) all point towards another very challenging year for UK potato growers, according to agronomist Fiona Law-Eadie.
Dividing her time between Produce Solutions, a division of Greenvale AP, and sister company Crop4sight – a potato-based software management company, Fiona annually advises growers across Shropshire, Herefordshire and Oxfordshire and, with 35 years of experience in potatoes, she predicts that 2022 could be one of the most challenging yet for the industry.
“There’s no doubt farmers have suffered significant product losses in recent years. Effective weed control strategies have been hit hard with the loss of both linuron and diquat and, with other products now under the regulatory spotlight, it’s not going to get easier in the foreseeable future,” she said.
“Within my territory challenges are linked to a large variation in soil types, including very light land unsuitable for metribuzin, a wide range of following crops and some metribuzin sensitive varieties, so early weed control planning is essential.
“On early chitted crops I prefer to get residual herbicides on as early as possible once ridges have settled and there is good moisture in the soil. Praxim (metobromuron) is certainly a go-to residual for me in the tank mix. It’s flexible, extremely crop safe and, when applied at a rate of 2.5L/ha, it shows good activity on a broad spectrum of weeds including annual meadow grass, common groundsel and annual nettles.
“In higher weed burden situations my tank mix preferences are either Praxim + aclonifen or prosulfocarb when dealing with metribuzin sensitive varieties, or Praxim + metribuzin if planting metribuzin tolerant varieties. On later planted crops, I generally favour applying both the residual and contact herbicides together in a single spray approach, normally at higher rates depending on the overall weed burden. As always, timing is the key with a one spray strategy and I’m looking to spray when there’s good soil moisture around 3-4 weeks after planting just before the ridges begin to crack.
To read our fuller feature, see the March issue of Potato Review. You can subscribe here.