South: Hot conditions a mixed blessing

The current unseasonably warm conditions have helped bring harvest to an end with the last few late crops of linseed and beans finally cleared.

Rape crops have enjoyed the warm conditions as well, putting on a huge amount of growth in the last few days. Most herbicide applications have gone on now and volunteers and broadleaved weeds have mostly been taken care of. Blackgrass levels are generally lower than last year and, yet again, Aramo (tepraloxydim) co-applied with a decent ammonium sulphate water buffer seems to have done an excellent job in this area at least.

I hear reports of phoma, but cannot find any in my crops as yet. My advice would still be to wait until the first lesions are seen before applying a fungicide. You will only get four weeks cover so applying now, before any phoma is seen, will simply result in a repeat application in early November. Leaf miner damage is very noticeable in quite a few crops but doesn’t warrant spraying.

Unfortunately the unseasonably warm and dry conditions are not conducive to good pre-emergence herbicide efficacy on cereals. Most farmers are well ahead with drilling and although seedbed quality is exceptional the performance of any flufenacet-based programme is likely to suffer.

Defy (prosulfocarb) has proven, in dry conditions at least, to perform relatively better. I have therefore tended to go for a mix of 4 litres/ha of Defy with 0.4 litres/ha of Liberator (diflufenican + flufenacet) rather than 0.6 litres Liberator plus 2 litres of Defy. The worst fields have recieved full rates of both.

I won’t even bother mentioning Crystal (flufenacet + pendimaethalin) since the manufacturer has decided to remove the remaining stocks from the UK market and sell it elsewhere. But then there is a sense of déjà vu here, they did exactly the same last year and caused all sorts of problems.

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