West: Herbicide programmes complete and effective

The seasons remorselessly swing round and another growing season looms large on the horizon. The winter has been kind to us in the Southwest and crops are emerging in good order. Most herbicide programmes are complete and working well save for a few later-sown winter bean crops where we could not apply pre-emergence propyzamide and are hoping for a weather window in February to apply carbetamide.

Lower commodity prices mean a sharp eye must be kept on costs this season, although the rents being demanded for some short term tenancies are eye watering.

Winter wheat on heavy, wet soil has turned blue and stressed in the colder spell and 40kg N/ha will go on as soon as weather and ground conditions allow.  Forward Solstice on lighter soils had patches of yellow rust prior to the cold snap but this has now receded. Earlier mildew in Claire and Leeds has dried up. Septoria is abundant on older leaves. Everything seems to be pointing to another expensive fungicide season. Last season’s results show big margins over input costs for SDHI programmes, but strikingly poorer results from azole/strob combinations. Chlorothalonil will continue to play a big role.

Winter oilseed rape is the usual mixed bag, with February canopies ranging from green area index (GAI) 0.5 to over 2. The larger canopies will need careful nitrogen management, it will be great to save a bit of money on this crop, as returns currently look woeful. Pigeons have moved in with a vengeance and unless moved on, will do some serious damage to smaller crops between now and stem extension.

Encouraging signs of grassweed death are now showing up from later-applied propyzamide. You do need to be patient with this product, but used correctly results can be excellent. The photo below shows the characteristic “spring onion” effect on blackgrass stem bases. The foliage may be green, but plant death will soon follow.


Little or no new incidence of Light leaf Spot has yet been seen, but a return to wetter weather could spark things off, so remain vigilant.

The restrictions on new label Galera (clopyralid + picloram) this spring are a headache. There is a 36 month interval before any crop except wheat, barley, oats, maize and oilseed rape, which may be sown within four months. That’s right, no pulses, potatoes, sugar beet or grass to name but a few for three years. Some stringent record keeping will be needed. Straight clopyralid remains an option where thistles and mayweeds are the target, but will be ineffectual on cleavers.  Unfortunately an appropriate dose of clopyralid will cost a lot more than full rate Galera.

Winter barley is classically yellow at the moment. We will not hesitate to get nitrogen on here as soon as possible. Canopies are generally large, so at least the blackgrass is having some competition.

Spring barley drilling has not started in earnest. We prefer to wait for good seed-bed conditions – spring barley forced into a poor seed-bed rarely matches one drilled well a little later. Rhynchosporium can be troublesome in very early sowings.

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