With winter wheats moving quickly through growth stages, the flag leaf is now emerging on forward crops.
T1 fungicides may have only been applied to these crops seven to 10 days ago, and the temptation will be to keep to the standard 21-day interval between T1 and T2.
As I write this, I can hear heavy rain at the window, and with active Septoria tritici sitting in the base of some crops my mind turns to rain splash moving spores in the base of the crop up the plant.
With the flag leaf contributing to more than 40% of yield, it is even more important than usual to protect it at the correct timing.
SDHI chemistry in the forms of bixafen or fluxaphyroxad will be employed at T2, mixed with either epoxiconazole or prothioconazole, with the latter forming a good base to control fusarium later on.
A multisite active ingredient such as chlorothalonil or folpet may also be added on susceptible varieties, or if wetter weather is forecast.
Late Weed Flush
Blackgrass control in winter wheat in the form of mesosulfuron + iodosulfuron went on later than the ideal timing in places, controlling smaller plants, but allowing larger, well-tillered blackgrass to grow away to produce seed heads.
To top this off, I’m now finding new blackgrass emerging out of cracks in the ground.
Later emerging broad-leaved weeds are also possibly going to cause problems, as crops are now nearing the cut-off points for most herbicide products, with some products such as mecoprop-P having already passed its cut off point.
In spring crops, the lack of weeds in some places is concerning, pointing to a later flush, especially as it is raining. These may prove tricky to control, particularly in spring barley, sugar beet and peas where intervals between broad-leaved weed control and graminicides need to be observed.