Proline can be used three ways at T1 depending on the type and severity of disease present, Bayer CropScience’s combinable crops manager Alison Daniels says.

“For septoria control and general stem-based disease clean-up, a half dose (0.4 litres/ha) with chlorothalonil should be sufficient.”

Where there is low-moderate eyespot and septoria, she suggests using it at 0.6 litres/ha.

“In 13 independent trials last season, it gave an average yield of 0.25t/ha, or margin over input cost of £18/ha, more than Tracker.”

In difficult eyespot conditions, the full label rate of 0.8 litres/ha should be used, she says.

Accurate timing of treatments is critical, adds the firm’s Nigel Godley. Generally, the best time for septoria control is by emergence of final leaf three, but this can be difficult to identify in the field, so many growers go by the number of nodes – equivalent to growth stage 32, he says.

“Proline has a reasonably wide window at GS31-32 for controlling septoria and eyespot.”

While he agrees a low dose (0.4 litres/ha) may be sufficient where there is low-moderate septoria risk, growers of susceptible varieties (rated below six) or those with forward, thick crops should use 0.6 litres/ha, he says.

BASF’s Andy Jones says Tracker is ideally suited to the T1 timing for septoria and eyespot control.

Temptation to apply T1s earlier this season on forward wheats should be avoided, he says.

“It could mean the gap between T1 and T2, or T2 and T3, becomes stretched allowing disease to come in.

“Where there is significant disease pressure, it is important to go in with a T0, such as Opus/Bravo to help clear up anything before T1.”

Tracker should be applied at about 1 litre/ha, but higher rates (up to the full 1.5 litres/ha) may be needed if eyespot is a big problem, he says.

A BASF survey last year found 95% of advisers, who applied Tracker, used it at T1, at an average dose rate of 0.98 litres/ha. Respondents cited eyespot, followed by septoria control, as the most important reasons for choosing the product.

Some 77% said the product gave “good or excellent” septoria control, while 59% considered its eyespot control as “good or excellent”.

paul.spackman@rbi.co.uk