Iblon® performance heralds change of fungicide policy on Nottinghamshire estate

Richard Cross is about to revise his fungicide regime after a trial in 2023 returned a positive, albeit unexpected, result. From a change in T1 fungicide application, a crop of KWS Extase yielded almost 0.5 t/ha more than that receiving the farm standard. For Mr Cross, farm manager at Oxton Estate and winner of the National Arable and Grassland Awards farm manager of the year 2024, the result is akin to a changing of the guard.

“I was fortunate to have Iblon® , Bayer’s new broad-spectrum fungicide containing isoflucypram, to test during 2023. The rest of the programme was as per the farm standard,” says Mr Cross.

“The result came as a shock. All fungicides were well timed and there was little discernible difference between treatments, but Iblon® at T1 outperformed Ascra® Xpro® + Arizona® by 0.49 t/ha. The fungicide policy has been reviewed following this result,” adds Mr Cross.

Winter wheat is the dominant crop in a rotation that includes maize on non-irrigable land and field vegetables on that which can be irrigated. To spread the production risk and the seasonal workload, the wheat area typically comprises a mix of milling and feed varieties.

“Roughly a quarter of the farm is irrigated sand and gravel. Skyfall has been the preferred variety on this land in recent years while Gleam and KWS Dawsum make up the first wheat on the heavier land with KWS Extase sown as a second wheat,” says Mr Cross.

Across 700 ha of arable north of Nottingham, Septoria tritici dominates the disease pressure, though yellow rust is a considerable threat. “Yellow rust is just easier to control,” says Mr Cross.

For logistic ease, a crop of KWS Extase was selected for the fungicide trial. It’s excellent Septoria and yellow rust resistances, AHDB scores of 7.4 and 7 respectively, led Mr Cross to consider a field with either Skyfall or Gleam as a more worthwhile alternative, but the convenience of having the trial in a field immediately next to the yard won out.

“I wanted to be able to monitor it easily while minimising the downtime at the T1 timing,” he says.

With the exception of Vimoy® (Iblon® ) + Proline® (prothioconazole) at T1 instead of the farm standard of Ascra® Xpro® (bixafen + fluopyram) + Arizona® (folpet), the trial received the same programme as the rest of the field. This comprised a T0 of tebuconazole + folpet, T2 of Univoq® (fenpicoxamid + prothioconazole) and a T3 of Ascra® Xpro® .

Disease scores from Bayer’s CropCheck service reported a pre-T1 score of 96 for Septoria suggesting a high inoculum carry over and the need for a fungicide with strong curative and protectant activity. By the timing of the T2 spray, the Iblon® treated crop had a Septoria score of 36, suggesting this had contained the disease but also that the T2 spray should have good protect activity. In contrast, the CropCheck score for the crop receiving the farm standard at T1 had a Septoria score of 67, suggesting control had been less effective. Yellow rust was virtually undetectable.

“Iblon® will become the standard T1 application on the quality wheats and those drilled in the normal sowing window. Late-sown crops with less disease pressure, will continue to receive Ascra until such a point that its performance dictates a change.

“This follows much the same path as with Aviator® 235 Xpro® (bixafen + prothioconazole) following the launch of Ascra® Xpro® . No doubt Iblon® will have its day in the sun too,” says Mr Cross.

Richard Cross, farm manager at Oxton Estate, was impressed with the yield uplift delivered by Iblon® .

Acknowledgements: Ascra, Aviator, Vimoy and Iblon are trademarks of Bayer. AscraXpro contains bixafen, fluopyram and prothioconazole; Vimoy contains isoflucypram. Arizona is a trademark of Adama. Arizona contains Folpet. Univoq is a trademark of Corteva Agriscience. Univoq contains fenpicoxamid and prothioconazole.