Iblon® performs in the face of heavy Septoria pressure

On-farm trials are often the grower’s favoured means of comparing the performance of different products and techniques.

For Adrian Howell, farm manager at Westacre Farms, Norfolk, the opportunity to test a new fungicide that promised unrivalled broad-spectrum activity was one not to be missed.

Across 200 ha of winter wheat on predominantly sandy loam soil, Septoria tritici dominates the disease complex, with brown rust and mildew a problem in some seasons. This is borne out by CropCheck results which rarely return a score for yellow rust, and with no second cereals in the rotation, stem-based diseases are also of little concern for him.

“We’ve had iblon + prothioconazole in farm trials for two of the past three seasons and it has impressed with its excellent control of Septoria from the T1 application,” Mr Howell says.

“In 2021, a season where Septoria wreaked havoc, it outperformed the then farm standard of Revystar®, and in 2023 it outperformed the current farm standard of Myresa® + Priaxor® + Arizona®.

“In addition to producing higher yielding crops through better disease control, it sprayed well and there were no crop or equipment concerns,” he adds.

In spring 2023, CropCheck tests pre-T1 returned a Septoria score of 44, indicating a crop with early stage Septoria infection, though most likely still in the latent phase so not necessarily presenting visible symptoms. Such a result could be expected to warrant the use of a fungicide with both curative and protectant activity.

At the T2 timing, Septoria on leaf 3 in the crop that received the farm standard T1 application of Myresa® (mefentrifluconazole) at 1.0 L/ha + Priaxor® (fluxapyroxad + pyraclostrobin) at 0.4 L/ha + Arizona® (folpet) at 1.0 L/ha, had increased to 48, suggesting that this combination had failed to stop the spread of the disease to new leaf tissue.

In contrast, the Septoria score for the crop that received iblon® at 1.0 L/ha + prothioconazole at 0.6 L/ha was 24, suggesting this had contained the disease thereby relieving the pressure on the T2 application. Nonetheless, the T2 spray should contain a product with good protectant activity.

“The stronger curative and preventative activity of iblon® was reflected in less disease on leaf 3 at the T2 timing. The value of which was evident at harvest when the iblon® -treated crop delivered an extra 0.15 t/ha (corrected to 14% moisture content) over the farm standard.

At forward prices for May ’24 of £200 /t, this is an extra £30 /ha. Across 200 ha of winter wheat this is a useful sum,” he says.”

Acknowledgements: iblon is a registered Trade Marks of Bayer. iblon contains isoflucypram. Arizona is a Trade Mark of the ADAMA Group. Arizona contains folpet. Myresa and Priaxor are Trade Marks of BASF. Myresa contains mefentrifluconazole. Priaxor EC contains fluxapyroxad + pyraclostrobin.