What's happened to my oats?

[Tractor Boy]

Just noticed my Spring oats have gone from green to this over the weekend. First time I've grown oats. Is it some kind of heat or chemical scorch?
Unless it's a kind of Septoria it's not another disease. Is it a nutrient deficiency? Soil type is clay so not droughted.

 

[Gong Farmer]

Can't be certain but could be oat septoria, or dreshlera. Has it had fungicides?

 

[mushnt grummmble]

Has it been sprayed

 

[Tractor Boy]

Can't be certain but could be oat septoria, or dreshlera. Has it had fungicides?

It had epoxiconazole 0.6 plus fenpropimorph 0.33 at gs 31 mid May then Mantra 0.9 plus corbel .3 on 15th June before the sun got too hot I thought.

 

[Tractor Boy]

Has it been sprayed

15 th June last spray and it was green. Noticed it had gone like this yesterday. The whole field is like it!

 

[Tractor Boy]

@Fromebridge if it is dreschlera, is it seed borne? This is my first time growing oats so the seed was C2 and treated. What can I do? Has the disease done its damage or is it going to completely defoliate the ears as well?

 

[Sprog]

I sprayed mine on the 16th and have the same result. Did you have any growth reg in the mix?

 

[Tractor Boy]

I sprayed mine on the 16th and have the same result. Did you have any growth reg in the mix?

No. Just Mantra and Clayton Spigot(fenpropimorph).

 

[Gong Farmer]

@Fromebridge if it is dreschlera, is it seed borne? This is my first time growing oats so the seed was C2 and treated. What can I do? Has the disease done its damage or is it going to completely defoliate the ears as well?

It is seed-borne but most/any seed treatment should control it. I probably shouldn't say this but in your programme the only triazole is epoxi and in one trial we did that was the only triazole that didn't control it.

Not total agreement with the pics here so still can't be certain though (p. 47)

https://cereals.ahdb.org.uk/media/185607/g41-the-encyclopaedia-of-cereal-diseases-2015-branding-.pdf

 

[Cordiale]

As Fromebridge says it looks like drechslera, a seed born disease of oats.
I have seen this twice before, once in winter oats, and once in spring. Both crops were grown from certified treated seed. The springs went on to yield just shy of three ton, the late sown winters were killed by hot weather prematurely but still managed about 2.5.
The only thing that has much effect is pyraclostobin (comet), which from memory is in mantra I think. So hopefully you will have some protection on the bells. Good luck for a decent yield.

 

[Gong Farmer]

Mantra is epoxiconazole, fenpropimorph and kresoxim-methyl.

 

[Cordiale]

Mantra is epoxiconazole, fenpropimorph and kresoxim-methyl.

Well I was close, I knew it was a BASF product, but didn't realise it was their first generation strobe in the mix. I didn't think anybody used kresoxim-methyl much in cereals now?

 

[Tractor Boy]

I can't make out how it's come in if it is dreschlera. Treated seed, fields surrounding and this field haven't grown oats for over 20 years, if at all. This Spring has hardly been a high disease year. Everyone said oats only ever get rust and mildew and a cheap fungicide is all that's needed.

 

[The_Swede]

Just a slightly off the wall thought but grass weeds etc?

http://www.sciencedirect.com/science/article/pii/S0007153684801527

 

[Tractor Boy]

Just a slightly off the wall thought but grass weeds etc?

http://www.sciencedirect.com/science/article/pii/S0007153684801527

That field is actually relatively clean.

 

[Tractor Boy]

Another thought. Is it likely the epoxiconazole entered the leaf( I know it's a slow moving triazole) and didn't dissipate so was in very high concentrations inside the leaf during an extremely hot spell of weather. This hot weather on the leaf has scorched certain areas and killed them.
I know chemical scorch is usually where the stuff races to the leaf tip but as said epoxiconazole is very slow moving.

 

[texelburger]

We have the same symptoms in our spring oats,saw it last year too. They had two fungicides and we're not sure what is causing it.Last year with these symptoms they yielded just shy of 3 t/ac ,so reasonably happy.Wish i knew what it was and if there is something we could do to prevent it,though.

 

[DRC]

If you remember , I had a similar thread when my winter oats showed the same markings. They grew out of it and we reckoned it was chemical scorch, even though we'd been very careful with mixes and timings .

 

[Gong Farmer]

Well I was close, I knew it was a BASF product, but didn't realise it was their first generation strobe in the mix. I didn't think anybody used kresoxim-methyl much in cereals now?

Just oats! The KM still controls oat mildew.

 

[shakerator]

Another thought. Is it likely the epoxiconazole entered the leaf( I know it's a slow moving triazole) and didn't dissipate so was in very high concentrations inside the leaf during an extremely hot spell of weather. This hot weather on the leaf has scorched certain areas and killed them.
I know chemical scorch is usually where the stuff races to the leaf tip but as said epoxiconazole is very slow moving.

I think it's the morphaline . Known to defoliate in hot weather