Nitrogen rates on wheat crops this season.

[chipchap]

We suffered disease breakdown on the ear at the end of last season, having used a total of about 230 units N, with a robust fungicide programme.
I am considering cutting my N input this season to lower disease pressure.
Varieties Crusoe and Cordiale.
Location Shropshire Herefordshire border.
Maybe we need to just get more. N on earlier?
I would be especially interested in any comments from the Emerald Isle, where I know disease control is a constant battle.
My thought is that disease organisms are evolving faster than the fungicides available can cope with.

 

[John Slejpner]

Crusoe was being slaughtered by brown rust in any trial i saw last summer..i'll bet a bit of Comet would have protected it and i'll bet more that a bit of comet featured nowhere when the fungicide strategy was being drawn up.
Its all about 2 SDHI's and septoria don't you know.

This observation may have no relevance to your situation.

 

[MNBVCXZ]

Not sure you should do this year what you think you should have done last year.
How robust was the programme?

 

[franklin]

Amistar still decent on brown rust. Amistar Opti never seems over dear.

Too much AN, rather than urea, early on doesnt seem to help. You are in a different part of the country to me, so pinch of salt. Given the current season, I dont think it will be prudent for me to reduce N rates. And if it does warm up, I think T0 and T1 may come together. If they do, then I may go old-school of a litre of Amistar Opti, and a litre of Opus. If less brown rust and more mildew, then litre of Mantra.

 

[chipchap]

We did T0, T1, T2, T3, T3.5. Belt and braces job the agronomist and me thought.

 

[Brisel]

Can you do more N splits to reduce the lush growth that boosts plant tissue nitrates and therefore disease susceptibility?

Front loading the N programme is fine but that leaves it open to lodging and early disease whilst reducing grain protein. The hot dry weather last year just suited rust instead of the usual wet that favours septoria that does mean you're on a SDHI based programme. I see you're in South Shropshire - would you say your climate was wet? Some bits can be in the Welsh rain shadow but others make for great grass growing.

 

[chipchap]

Put it this way, we don't irrigate any of our potatoes.

 

[ollie989898]

Conditions during flowering determine likelihood of ear disease, N is secondary. As above put strobilurin on for good protectant activity vs rusts.

 

[Andrew K]

Used 5 sprays on Crusoe last season without any brown rust issues. It depends on climate and robustness and timing of sprays IMO.

 

[Brisel]

Put it this way, we don't irrigate any of our potatoes.

That suggests a wet climate that favours septoria so the rusts ought to be covered by that programme. Prothioconazole seems to be becoming more popular in SDHI mixes. This isn't as good on rusts as epoxiconazole, especially yellow rust. Ascra & Elatus both have prothio so beware of rust activity if using these. There are plenty of good epoxi based products like Adexar that will cover you well for rust too at T2. I'm not sure what Librax is like on brown rust.

 

[ollie989898]

Get the rust out of the crop early, if its there at T0 it can get out of hand by April, its where CTL alone isnt going to cut it. Its the same with mildew, the ground drying out will give localised humidity and give a storm of yuk early I bet. Im not convinced the SDHI sorts everything mentality is accurate.

 

[chipchap]

Rusts aren't often a major problem for us. It's usually Septoria and Ear disease complex.
Thanks for all the interesting replies.