Wheat diseases are slow to develop so far this season
Wheat growers who are intent on utilizing early-season fungicides might do well to postpone an application for now.
Despite wheat’s early development (currently ranging from Feekes growth stage 5 to 7), leaf disease levels have been low if not completely absent. For wheat growers that have not yet applied their early fungicide treatment, it may be advantageous to postpone any action until diseases become apparent.
The slow start to spring-time diseases, such as powdery mildew and Septoria leaf spot, can probably be attributed to overly cool and mostly dry conditions during April.
As a reminder, leaf diseases in moderate level cause little yield loss during the early growth stages. It is only when wheat’s flag leaf begins to emerge (growth stage 8) that foliar disease needs to be taken more seriously. In the weeks to come, growers are encouraged to keep an eye for disease infection on the second leaf (the leaf immediately below the flag). If this second leaf shows several new infections, growers might do well to consider a fungicide treatment during full flag or boot stages if conditions favor further disease development. However, where disease development is minimal, growers should consider postponing the treatment until the early flowering stage in order to target both the leaf disease and Fusarium head scab.
A fact sheet titled “Managing common leaf diseases in wheat” shares additional information on the most common diseases and provides a list of currently recommended fungicide products.