Cereal disease management: May T2 decisions in the West Midlands & North West

Across Grace’s patch in the West Midlands and North West, winter barley is moving quickly and will be first in line for T2 decisions in May. In some of the more forward crops, T2 could be due from the end of the first week of May, so there isn’t a lot of slack in the system.

The aim in winter barley is clear: time fungicides to cover both the flag leaf and the awns, because in barley it’s the awns that do a big share of the yield-building work. At the same time, winter wheat is heading towards flag leaf, spring barley is motoring through growth stages, and beet, potatoes and maize all need attention.

For agronomists and growers, May is about prioritising: getting the key cereal timings right, while keeping an eye on disease pressure, budgets and spray days.

Winter barley: T2 timing and ramularia risk

T2 on winter barley will come around quickly for forward crops, so be prepared for it from the end April into the first week in May. The outcome we are looking for is to cover the awns as well as the flag leaf because the flag leaf in barley is relatively small the awns are what contribute significantly to yield, so protecting them pays.

Options Grace is recommending at T2, depending on disease pressure:

• Low disease pressure: Siltra® 0.4 - 0.6 L/Ha a solid, good-value base option.

• Moderate disease pressure: Ascra® 0.7 L/Ha if it hasn’t already been used at T1

• High disease pressure / ramularia concern: Vivalis® 0.8 L/Ha– the strongest option from the Bayer range where ramularia is a real worry. Bringing in our new SDHI lifts ramularia activity and overall disease control.

Grace also advises:

Later T2 timings are more effective for reducing ramularia in the crop as is adding a multi-site such as Folpet at T2 which also helps protect the other chemistry from the development of disease resistance management Just before the traditional T2 timing, is also realistically the last window for late-season PGRs in winter barley so if brackling is still a concern, finishing the PGR programme with something like Cerone® at this stage can help strengthen straw and reduce lodging risk but be careful with ensuring growth stage cut-offs are strictly adhered to and that the crop is not stressed.

Winter wheat: holding your nerve on T2 product choice

By the time we reach early May, all winter wheat in the region should have had its T1, ideally applied in a protectant situation on a fully emerged leaf 3. That should help shield that leaf from the inoculum of the main diseases whether that’s Septoria splashing around during a rain event or Yellow Rust arriving on the wind from the East of the country.

T2 is likely to fall from the third week of May onwards, once the flag leaf has fully emerged. Grace’s key message is not to rush T2 product decisions too early as disease pressure at T2 will depend heavily on the weather during May. If it turns dry and stays cool at night, you may not need the most potent chemistry on whatever disease is the most talked about when it gets to decision time. Consider what’s actually there in your fields and remember a well-timed T1 fungicide which incorporated an SDHI will typically give around 3 to 3.5 weeks protection.

Grace outlines three broad T2 scenarios based on disease pressure:

1. Low disease pressure (dry, low septoria, rust under control)

Ascra® at 1.2–1.5 L/ha:
Strong on both yellow and brown rust. Good septoria suppression. Mirrors last year’s situation in many areas, where septoria pressure at flag leaf was very low but the physiological benefits of the SDHI’s alleviated the drought stress of treated crops.

2. Medium disease pressure (showery, mixed septoria and rust)

Plaxium® at 1.2–1.5 L/ha:
Effectively “Ascra turbo” Bixafen is replaced by isoflucypram, our latest SDHI which gives better all-round disease control packaged as a single co-form solution and benefiting from the same Xpro formulation that enhances all aspect of fungicide performance.

3. High disease pressure (very wet May, septoria racing)

Jessico® Fusion at T2:
Bayer’s innovative combination of isoflucypram and fenpicoxamid. One of the strongest T2 options in the market where you need to deal with extreme septoria pressure and yellow and brown rust which has the added benefit of being all together in one can.

Programme planning: what you did at T1 matters

Grace stresses that T2 choices are constrained by T1 decisions: If you used a Vimoy® / isoflucypram product at T1, you cannot use Plaxium® or Jessico® Fusion at T2. Fenpicoxamid is also limited to one use per crop so if it was used at T1, Jessico® Fusion is off the table at T2.

This year we need to make T2 a strategic decision rather than just picking the “strongest” product.

Rust “T1.5” top-ups

Grace suggests monitoring closely for yellow rust, especially in varieties with known susceptibility or where YR15 mutations are a concern. If yellow rust starts “bubbling up” again from the lower leaves between T1 and T2, a cheap, low-dose rust tidy-up can be justified. A well-timed dose of tebuconazole or tebuconazole + strobilurin can help keep the rust at bay. This stops infection climbing higher up the canopy and leaving you chasing your tail through the remainder of the season. It’s not an automatic extra spray, but a case-by-case decision, but it could be essential if intervals are stretched, as the cycling speed of yellow rust means it could take hold and rob you of so much yield if you decide to sit and wait for the right Septoria timing.

Spring barley: quick growth, simple but important choices

By early May, most spring barley in the West Midlands and North West should be in the ground and emerging with grassweed control completed where possible. Ideally this would be with a residual herbicide to tackle meadow-grass and, where relevant, black grass or rye-grass.

Fungicide options in spring barley

Siltra® at 0.4 L/ha:
A very good base option in lower disease pressure situations. Xpro® formulation, broad-spectrum disease control.

Ascra® at 0.7 L/ha:
The stronger level of control for crops with good potential and particularly where net blotch is a concern. The Fluopyram in Ascra® improves activity over a straight bixafen + prothioconazole mix and builds a strong resistance management strategy.

Both Siltra® and Ascra® are fully approved by the Institute of Brewing & Distilling, so they are suitable for spring malting barley with no issues from a brewing perspective. Grace acknowledges the temptation to go very cheap with straight prothioconazole but highlights the value of robust formulations that are rainfast in minutes with good tank mixability. Especially when fungicides are going in with other inputs which as we know is very common practice with Spring Barley based on the number of multi-way tank questions we receive.

Sugar beet: finishing herbicides and watching for aphids

Sugar beet crops are at a range of stages depending on drilling date and how dry it has been, but during May many fields will be well through their herbicide programmes. This month will see the final herbicide applications going on, with programmes typically built around Betanal® Tandem type products with additional partner herbicides based on the broadleaf weeds present and the grassweed pressure.

For Conviso® Smart crops, the month of May could be when we reach the first herbicide timing so it’s important to remember that only one application of Conviso® One is approved. Grace advises targeting indicator weeds such as fat-hen at around the four-leaf stage, if it remains dry then adding in some adjuvant in the form of Mero can help lift performance. Conviso® One is only for Conviso® Smart beet varieties and must not be used on conventional beet.

Early-season virus-transmitting aphids can cause significant yield loss, so May is a good time to walk crops and check for aphids and compare against treatment thresholds. Where these are met, Sivanto® Prime is a useful option as part of a programme being highly selective on aphids whilst also having a favourable profile for beneficial insects, helping preserve natural enemies. There was no emergency approval for Movento® this year, so threshold-based decisions are essential.

Potatoes: planning blight programmes around new strains

During May, potato crops will likely be emerging and starting to grow away, hopefully with weed control largely completed. The focus now turns to blight control programmes, particularly considering EU46 and EU43 strains detected in the UK.

(EU46: reduced sensitivity to OSBPI and CAA chemistry. EU43: reduced sensitivity to OSBPI chemistry.)

Grace’s key points for blight programmes

1. Use different modes of action throughout the programme.

2. Avoid block treating with multiple consecutive sprays of the same mode of action.

3. Infinito® is a valuable tool:

   1. Protects against both EU46 and EU43 strains..

   2. Works well if introduced early in the programme such as the second or third spray, then at intervals throughout rapid canopy growth.

Aphid monitoring in potatoes will become more important as crops approach flowering, but Grace suggests starting to keep an eye out now.

Maize: weed control planning

Maize drilling in the West Midlands and North West should be largely completed by late May, with crops starting to emerge. In practice, this means the timing for post emergence sprays like Maister® is likely to be late May into early June so something to mark in the diary for a later date. There could be some earlier-drilled, early maturing varieties or some maize under-film which may reach leaf 2 by late May and so Maister® 150 g/ha + Mero and an additional partner (e.g. a half dose of another suitable herbicide) to widen the broad leaved weed spectrum would be a strong choice.

Final words from Grace

“Barley’s flying and wheat’s not far behind, so May is all about getting those key timings right. If we match our fungicide choices to the actual disease in front of us, protect the awns in barley and the flag leaf in wheat, and keep an eye on beet, spuds and maize as they move, we’ll be in a strong place going into summer.”

Ascra® Xpro® contains bixafen, fluopyram and prothioconazole. Jessico® Fusion contains isoflucypram and fenpicoxamid. Plaxium® contains isoflucypram, fluopyram and prothioconazole Vimoy® (Iblon®) contains isoflucypram. Siltra® Xpro® contains bixafen and prothioconazole. Sivanto® Prime contains flupyradifurone. Movento® contains spirotetramat. Conviso® One contains foramsulfuron and thiencarbazone-methyl. Betanal® Tandem contains ethofumesate and phenmedipham. Infinito® contains fluopicolide and propamocarb. Maister® contains foramsulfuron and isoxadifen-ethyl . Ascra, Conviso One, Jessico Fusion, Vimoy, Iblon, Xpro, Betanal Tandem, Infinito, Sivanto Prime, Movento Maister and Mero are registered trademarks of Bayer. All other brand names used are trademarks of other manufacturers in which proprietary rights may exist. Use plant protection products safely. Always read the label and product information before use. Pay attention to the risk indications and follow the safety precautions on the label. For further information, including contact details, visit www.cropscience.bayer.co.uk or call 0808 1969522. © Bayer CropScience Limited 2026