South – Unseasonably mild weather brings disease

The key observation concerning all crops this autumn has been the prolonged unseasonably mild conditions. We’ve had enough rain to get full germination now in all the cloddy, baked-out backward areas, but it doesn’t look as if there was enough residual herbicide hanging about to be successfully reactivated. Consequently over the last week or so I’ve seen a considerable emergence of blackgrass in places, and follow up treatments are now becoming necessary. The good news is that the mild, growy conditions should mean the Atlantis-type follow ups should work very well.


The mild conditions have brought on an onset of disease, particularly mildew. Net blotch and rhyncho are being found in barley, along with low levels of both brown and yellow rust in wheat. I am taking note of this, but apart from the worst mildew cases in barley on thin soils, I’m not yet taking remedial action. What it means though is my early spring fungicide applications are likely to be extremely robust.

Phoma is now starting to appear in winter oilseed rape, but as it is fairly late in the season and most rape crops are quite big, I don’t think it’s very high risk. I was hoping to time my fungicide applications to coincide with propyzamide/carbetamide applications, but the soil temperatures are still far too high for these to work properly, so it looks like it will have to be a separate pass with the fungicide.


I’m still waiting for a decent cold spell to come along and bring things back into line. If it doesn’t happen I fear we will be in for a very challenging spring. Anybody remember the spring of 2007? There is a certain amount of disgruntlement amongst my growers as I’ve told them they can’t put their sprayers to bed for the winter yet – not until the winter actually arrives.

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