Article taken from Agronomist & Arable Farmer, June 2017, written by Agrovista agronomist Stuart Dun.
Cereal crops have perked up after some welcome rain returned in mid May.
Spring barleys have been incredibly variable, depending on how much moisture they were drilled into. Those sown into spring-ploughed land or cobbly seedbeds were only just showing a hint of green two weeks ago, though they are starting to catch up now.
There was little sign of disease in spring barley back then, so most crops received a light rate of fungicide at Tl, based on 0.35-0.45 litres/ ha of Jaunt (fluoxastrobin + prothioconazole + trifloxystrobin) plus plant growth regulator. Midlothian, in the east of my area, tends to be drier so received the lower rate - the weather in Stirlingshire and Lanarkshire is more unpredictable, so crops need a bit more protection.
T2 is the key timing and I'll use Jaunt again, this time at 0.4-0.GL/ha according to disease presence. Depending on budgets, I'll recommend a multi-site partner, either Arizona (folpet) or chlorothalonil at IL/ha. on variable crops we'll have to assess when most of the field is at GS49 and then spray.
Folpet seems to improve Jaunt's activity quite considerably, so I prefer it at this timing. There can be quite a long time between T2 and harvest and Ramularia and Rhynchosporium are a constant threat, especially on Concerto, which makes up most of the malting barley area I look after.
The rise in popularity of Scholar, a high-yielding variety with better disease scores, will help. It is also finding favour because it is stiff - most feed growers don't want to apply a plant growth regulator as they want all the straw they can get.
Spring barley can often run short of magnesium and sulphur. I'll add Headland Magnus at IL/ha to the T2 spray, to enhance chlorophyll production and help maximise grain fill. Some winter wheat crops are looking very well, but others lost a few tillers due to the long dry spell.
Dead leaves, which are not caused by disease, are easy to find in the bottom of crops. However, wheats still have plenty of potential and should compensate for this.
There has been quite a lot of Septoria tritici, despite the lack of moisture. This will have been spread up the plant by the recent rain, so I maintained a robust, SDHI-based programme at T2, which also helped to dry up mildew that was creeping into some crops.
As a result of this strategy, wheat will be in good shape disease-wise . However, T3 will go on as standard - we've not had a bad Fusarium year here for a while but if rain does strike during that early flowering period the risk is always there.
I'll also be looking to top up Septoria control at this point - this far north there can be a couple of months between T3 and the combines moving in, so we need to keep on top of it.
I'll use Monkey, which contains prochloraz + tebuconazole, both of which have good activity on Fusarium and Microdochium fungi that produce mycotoxins in grain. The standard rate is IL/ha, which I'll adjust up or down, depending on disease pressure.
This is a good time to look for brome patches creeping in from headlands. Making a note now of where these occur will help ensure they are not combined and spread across the field, and can be targeted for top-up weed control treatment next time around.
Stuart Dun is an Agrovista agronomist based in central Scotland (stuart.dun@agrovista.co.uk)