How to keep cereal disease in check this May in the Midlands
Crops were looking pretty well as this is written in the third week of April, but we’ve only had 2mm of rain in April so far at our trials site at Hinton Waldrist, near Oxford, which is not clever and considerably less than 12 months ago in this region.
So while crops have fared well up to this point that’s going to change unless there is some moisture in the next fortnight which at the moment isn’t looking particularly likely. That’s mainly for the nitrogen which is lying on the surface, and without it being washed in, crops are going to be hungry.
That’s the bigger concern at the moment, much more so than disease. There’s a little bit of yellow rust in a few wheat varieties, which has been curbed back by the frosts more than I was expecting, and Septoria is virtually non-existent. Where it is present it is on older leaves and with a little bit of rain could take off, but with more resistant varieties in the ground that will help people out no end.
There is also likely to be a smaller gap between wheat T1 and T2, as the colder weather has delayed leaf three emergence. Some T1s might not be applied until early May, but flag leaf emergence will still likely be around 20-something of May as it will race through growth stages. If you’ve done a half-decent T1 it should stay protected quite easily between the two sprays.
Oilseed rape was growing well, with fewer losses to cabbage stem flea beetle larvae than I expected, but the frosts in April have kicked seven bells out of some crops and stopped it in its tracks. While cool and dry conditions mean Sclerotinia risk is low there is a lot of light leaf spot in some crops, even in tebuconazole-treated more resistant varieties.
Ben’s agronomy tips for May
- Tailor T2 sprays to conditions
- When is the best timing for the second spray in winter barley?
- Decide on one or two sprays in spring barley