5 May 1995

Winter cereals suffer local frost damage

FROST damage to winter cereals is becoming increasingly apparent as barleys come into ear and consultants and growers examine wheats more closely.

Once again Cotswold growers seem to have been hardest-hit, although the real extent will not be known until full ear emergence. In 1990 forward crops of Torrent winter barley they were badly affected.

Temperatures dipping to -10C (14F) in places on Apr 19-21 have left some growers with up to 80% tiller death. But the problem is regional rather than national, stresses Dr Mike Carver, director of Cirencester-based Arable Research Centres.

ADAS says frost damage is "widespread" with reports from Wiltshire to Kent and other eastern counties. But the effects are localised and mainly confined to frost pockets, according to Cambs-based John Garstang.

Forward Gaelic winter barley has been particularly vulnerable. Damage in wheats is not confined to the early-maturing Soissons. Hussar, Mercia and Riband have all been affected to some degree.

Most obvious symptoms are empty grain sites in emerging barley ears. Outwardly winter wheats appear unaffected. But cutting stems reveals dull watery ear primordia which turn brown as they abort.

Crop consultants in Hants report few problems. But Brian Keen, an AICC agronomist at Burford, Oxon, reckons 90% of winter cereals in his area have signs of damage.

Its extent depends on field aspect and crop growth stage, but some fields have lost 80% of stems. "It seems that those just into GS32 (second node) have suffered most – mainly early drilled wheats, although there is some quite serious barley damage."

ARC experience suggests crops with 70% tiller death are likely to have their yield cut by about 40%, putting them on a par with spring cereal output, says Dr Carver.

With most inputs already in place, scope for further crop management to take account of frost damage is limited, says Mr Garstang. The main aim should be to keep crops clean to allow surviving tillers to "compensate as best they can", he advises.

His advice is not to destroy crops but farm them to their lower yield potential.

But some fields have already been abandoned. "We know of one grower in the Pangbourne (Berks) area who has ploughed up 20 acres of Soissons," says Dalgetys national cereals seed product manager David Neale.

&#8226 Growers intending to plough up frosted crops already listed on IACS forms should inform their Regional Service Centre as soon as possible, says a ministry spokesman.