Fertilisers rather than fungicides should be the primary target of any input cost savings growers are intending to make this spring, ADAS fungicide expert Bill Clark is telling growers attending the HGCA’s Cereals Winter Workshops.

“It is easy for growers to say prices have gone down so they need to knock off 10-15/ha from the fungicide bill,” he says.

“But actually the wheat price doesn’t have very much impact on what you should do with fungicides.”

The basis for Mr Clark’s statement comes, in part, from HGCA trials investigating the optimum dose of Opus (epoxiconazole).

In the trials the economic optimum dose of Opus does not change much on each of four varieties regardless of whether wheat is priced at 60/t or 100/t.

“On Consort the optimum was around 1.5 litres/ha, while for Equinox it was 1.2 litres/ha.

Most farmers are not putting that much on.”

Indeed industry surveys suggest the average use rate for Opus is just 0.4 litres/ha, he says.

“With the pressure on advisers to cut input costs, most growers have cut fungicide use to way below the optimum.”

However, doing so is jeopardising both yields and profitability, he argues. For example on Consort, instead of applying 0.6 litres/ha Opus at T1 followed by 0.9 litres/ha at T2, growers could choose to save 15/ha by applying just 0.3 litres/ha followed by 0.5 litres/ha.

“That sort of cost saving looks good on paper.”

But, according to the dose response curve generated in the Rosemaund trial, yields are cut by around 0.7t/ha.

At wheat prices of 60/t using the lower Opus dose reduces the final margin by 12/ha.

With the cost of nitrogen soaring, fertiliser inputs could be a better target for cost savings, Mr Clark suggests.

The rising N price combined with low wheat prices means the optimum amount of nitrogen growers can afford to put on feed wheat crops has come down.

“When the breakeven ratio was 3:1 growers should have been putting on around 230kg N/ha [to feed a 9t/ha crop], at the current 6:1 ratio it should come down by 30-40kg.”

That cuts fertiliser cost by around 20/ha, without impacting too much on yield, he says.

But industry data suggests farmers didn’t respond last season by cutting rates.

“The farmer often hasn’t made that adjustment.

All I’m saying is growers must make sure the balance is right.

Instead of hacking away at fungicide inputs, look at your fertiliser spend first.”

mike.abram@rbi.co.uk