Bad weather hampers spring spraying programmes

Weather is still preventing spring management kicking into action, leaving our Crop Watch agronomists planning for when things get going.


Freezing temperatures as low as -17C in January had battered oilseed rape canopies in Devon, said Matford Arable agronomist Neil Potts. “GAIs are much reduced at 0.6-0.8 compared with nearly two before pre-Christmas.”

This meant the top-dressing regime would have to be beefed up to help rebuild canopies. Consequently, nitrogen and sulphur applications would take place as soon as ground conditions allowed, he said.

Most cereal crops had emerged from the cold spell unscathed, with the exception of some barley crops, which had suffered significant winter kill due to manganese deficiency.

But the cold weather hadn’t managed to hold back septoria, with many forward wheat crops suffering from infection. “These will definitely be receiving a T0 fungicide – product choice will depend on the severity of the disease, crop size and varietal resistance,” he said.

In the east T0s were high on the agenda, particularly in varieties susceptible to rusts and septoria, said Prime Agriculture’s Marion Self.

“A mix of cheaper triazoles plus or minus chlorothalonil (as appropriate) will reduce the risk of early infection,” she said.

Protection was a much cheaper option than eradication and applying a T0 allowed greater flexibility at T1, she explained.

The cold winter had held back crop growth, but wheat oilseed rape and bean crops looked strong going into the spring. As soon as it started to warm up rapeseed crops would be ready for their first nitrogen application, usually including sulphur, she said. See Marion’s video on oilseed rape canopy management at www.fwi.co.uk/cropwatch

Fields were being selected for Atlantis (mesosulfuron + idosulfuron) applications and oilseed rape crops were being picked for applications of Galera (clopyralid + picloram) to control sow thistles and suppress cleavers.

Northern Crop Watch agronomist David Cairns reckoned 80% of crops in the Berwick area he managed had received autumn herbicides, which had worked well. “Any untreated crops that need annual meadowgrass control will probably receive Othello (mesosulfuron + idosulfuron + diflufenican.”

Yellow rust had been found in his area and as most of the varieties planted were susceptible to yellow rust, a T0 was high on the agenda. “All wheat crops will be getting a triazole/chlorothalonil fungicide at T0 as I don’t want to be chasing it all season.”

Some winter barley on lighter land had suffered from frost heave and was showing signs of manganese deficiency, he said.

“There has been a lot of chat about snow mould and snow rot in winter barley crops, but only time will tell if these materialise.”

Tidying up outstanding autumn spray recommendations was top priority for Chichester Crop Consultancy agronomist Tod Hunnisett from Sussex.

Atlantis (mesosulfuron + iodosulfuron) and contact graminicides should not be applied until temperatures increased, he said. “There is still time to apply diflufenican and chlorotoluron, but this varies depending on the rate or product used.”

The cold weather had held back disease and reduced the need for broad-leaved weed herbicides in oilseed rape, he added. “Many of the fields I’d earmarked for charlock control didn’t need doing.”