T3. Tailor product choice to match your local challenges.

T3 application timing and product choice are vital for good disease protection in cereal crops. Early ear emergence, rapid movement of foliar diseases up the plant and farm economics all mean that an effective T3 could be crucial this season. Product choice should not only be focused on controlling the quality and yield losses from Fusarium but also on foliar disease top-up, which will depend on variety and previous fungicide applications.

There are essentially 3 disease challenges in cereals at the T3 timing. Understanding which of these are relevant to your crop will be key to cost effective disease management.

Brown rust

Brown rust is a late season disease, typically associated with warm conditions at this time of year, where it can develop quickly especially on susceptible varieties. Effective management of Brown rust can be achieved cheaply with the use of a tebuconazole product. Apply 125g/ha tebuconazole (0.5L Clayton Tebucon® 250EW). There are a number of key varieties on the recommended list with weaknesses to this disease: Crusoe, KWS Cranium, KWS Guium, SY Insitor and KWS Siskin. Tebuconazole, metconazole and azoxystrobin are all rated 4 by AHDB for Brown rust control.

Fusarium head blight (FHB)

This disease is closely associated with a number of risk factors: rainfall and warm temperatures at flowering significantly increases the risk of infection whilst previous cropping with maize is also a major risk factor. Whilst a number of fusarium species can cause FHB and associated yield loss, Fusarium avenaceum, F. culmorum and F. graminearum are the pathogens associated with legal mycotoxin limit exceedances. Microdochium nivale is widespread and a major cause of yield loss through FHB, although it does not produce mycotoxins.

Product choice and timing are key to the effective management of this disease. Fungicides must be applied at mid-flowering GS BBCH 63-65, shown in the photograph below. High rates of tebuconazole will effectively control fusarium species but prothioconazole is required too for control of M. nivale, and AHDB / ADAS trials show best control can be achieved with products containing prothioconazole as a protectant at early flowering (GS63). Tebuconazole and metconazole both give good activity so using co-formulated products or tank mixes can be a good approach.