The late season and lower yield outlook points to less need for late foliar nitrogen on milling wheats, although an application could be useful if there is a long grain-filling period.

Advisers say that a final decision will have to be taken much nearer to the grain milky ripe stage for these applications on a field-by-field basis.

According to Dick Neale, tech­nical manager at advisers Hutchinsons, a great deal of the nitrogen already applied to crops either went on late or is being used late.

“We know that yields have been compromised in many areas. So in these situations, nitrogen levels are probably already sufficient,” he says.

However, Mr Neale adds that if the weather from now on allows for a long, slow grain-fill period, there could be some good yields from the better fields.

“And these are the sort of crops that will benefit from a late application. So it’s quite a conundrum this year,” he says.

His rule of thumb is that in a high-yielding year, the late foliar application is needed, but in a low-yielding year, it isn’t.

“That’s why growers will need to react on an individual field basis. They will know whether they have seen responses to late applications in the past, and if they believe that they have sufficient yield potential this year,” Mr Neale adds.

The fact that most wheat crops are disease-free, with access to plenty of soil moisture, means their ability to take up the nitrogen already applied is good, he says.

David Leaper, technical manager at Openfield, believes there is a stronger case for late nitrogen on lower protein milling varieties such as Solstice and Gallant, but stresses there is a reduced case overall this year.

“And those varieties with an inherently higher nitrogen content, such as Edgar, won’t need it,” he says.

“Yields aren’t expected to break any records this year, so the protein dilution that can occur in high-yielding milling varieties is less likely to take place. Holding back would seem sensible,” Mr Leaper explains.

Last year’s low yields and low specific weights ended up giving higher proteins than expected, he recalls.

“This season, we’ve got lower plant populations from later drillings. If they compensate by producing bolder grains, there could be some protein dilution. The difficulty is knowing how much,” Mr Leaper adds.

He continues that for those growers supplying a Warburtons’ milling contract, the late milky ripe application is not permitted. “They don’t see any benefit in the grist from it. So they accept grain at 12.5% protein.”

Mr Leaper’s advice is to base decisions on past experience, expected yield, the protein of the variety being grown, the status of the crop, and the farm’s previous success with hitting 13% protein.

“There aren’t any tests that can be done, as tissue analysis is a poor indicator. So growers will need to use their judgement,” he adds.

More on this topic

Read more on foliar nitrogen applications in milling wheat