April start for some T0 fungicides

First T0 fungicide applications are likely to be made next week, according to agronomists.

Wheat crops had started to move, Andrew Cotton, an independent agronomist from Oxfordshire told Farmers Weekly on Tuesday (23 March). “Given some decent weather, growers will be applying T0s next week, in mix with growth regulator.”

Yellow rust was the main driver, although not much had been spotted so far this spring in the area, he said. “It isn’t hitting us in the face yet, but you don’t want it to. You want to keep the inoculum down on susceptible varieties, such as Oakley, Solstice and Robigus, and growers are wanting to get on.”

He was recommending growers used a product with “a good slug” of triazole fungicide, in mix with chlorothalonil. “There are some reasonably priced products containing a triazole plus chlorothalonil.”

Septoria and manganese deficiency were showing up in crops more than rust at present, he added. The latter normally showed most in soils with high levels of organic matter or with a high pH. “It is showing up quite vividly this year, particularly on the Oxford clay soils. It seems to manifest itself when you get a growth spurt following a period of slow or no growth.”

Most wheat in Steve Baldock’s Norfolk and Suffolk patch would be receiving a T0, the Prime Agriculture agronomist said. “My cropping is biased towards varieties that are susceptible to yellow rust, but there is no rush yet as we are seeing very little rust.”

It was important to keep the gap between T0 and T1 to no more than three weeks if possible, he stressed. “You don’t want the interval to be too wide and let rust back in, so it will likely to be the first week of April before T0s start.”

Where Atlantis (mesosulfuron + iodosulfuron) had been applied he would be recommending Cherokee at a rate of 0.75-1.0 litres/ha, he said.

In Yorkshire, T0s weren’t likely this side of Easter Sunday, said David Martindale, an independent agronomist from the newly formed Arable Alliance. “And there will be a good chunk even later than that.”

Those crops might not even get a T0, he suggested. “The later crops will rush through the growth stages, so they might end up missing T0s, especially those late-drilled after potatoes, for example.”

Where a T0 was going to be applied, he too thought Cherokee would fit the bill this year. “We’ve still got a fair bit of Atlantis to do when it is warm enough, but with crops being behind on growth stage we’re hoping there is time to get it on before T0.”

Growers are starting to use Farmers Weekly‘s Rust Watch site to report sightings of yellow rust, and crops free from the disease too. To get the latest information on where rust has been seen go to www.fwi.co.uk/rustwatch and add your sightings to the map for a chance to win a weather station.