28 August 1998

On-farm trials study Hagberg test

A new system for predicting

grain quality ahead of

harvest is being assessed on

commercial farms for the

first time this year.

Andrew Blake reports

FIRST signs are that Hagberg predictions using the new Harper Adams test are reasonably accurate.

But delays getting results for southern farm samples taken on Aug 4 meant they arrived too late to influence harvesting patterns.

In the north, where wheat cutting has only recently begun, it is hoped the information may be more useful.

Hagberg forecasts should help growers decide the best order for harvesting to preserve wheat quality. That is the aim of the HGCA-funded £380,000 Harper Adams Agricultural College scheme (Arable July 24). It is being piloted with NIAB and the Association of Independent Crop Consultants.

Five of the first six post-harvest samples taken from four farms by Hants Arable Systems Steve Cook matched the forecasts. Harper Adams project leader Peter Kettlewell anticipated 80% accuracy. For Richard Porter at New Farm, South Warnborough, Basingstoke, one field of Rialto, which NIAB Labtest suggested was unlikely to achieve a Hagberg of 250, achieved 198. Another field of the same variety expected to deliver 250, especially if the weather stayed warm and dry (which it did), registered 261.

At nearby Red House Farm, Monk Sherborne, Peter Boyles Abbot and Spark were both predicted to reach 250, the latter with a higher sprouting risk. They returned 290 and 271, respectively. "To be honest we were 90% done by the time we got the forecasts," says Mr Boyle. "I can see them being useful in other years, but they need to be speeded up."

At Vyne Lodge Farm, Sherborne St John, Basingstoke, manager Mike Dalgarno was also unable to exploit the forecasts in two fields of Hereward. "They were of limited help. But they did show we should probably keep them separate until we get actual results." One field expected to achieve over 250 registered only 214, despite the dry weather.

But other tests on the same lot, which NIAB found had a high sprouting risk, suggest a fully representative result for the take-all affected second wheat is tricky to get. "I had two tests done on it by two merchants straight after harvest and there is tremendous variation. One made it 150 and the other 240."

Peter Cheyney is not surprised to see his 7.7ha (19-acre) field of first crop Rialto at nearby Hyde Farm, Herriard, recording only 148 Hagberg. The forecast suggested it was unlikely to reach 250 in cool, wet weather. Although there was no rain between sampling and cutting, it was already sprouted at combining.

HGCA board and NFU cereals committee member Julian Gibbons of Upper Farm, Bradley, Alresford, had Consort placed in category 4 (unlikely to achieve 250 in cool, wet weather). "But it stayed dry and Hants Grain say it was 250-260."

Spark, which was placed in category 2 (may achieve over 250 in warm dry weather), was not cut first because it was unripe, he explains. "This year we have been lucky with the weather. But in a catchier season and in the midlands and further north I believe the forecast should certainly help."

In E Yorks, where wheat combining began only recently, the AICCs Andrew Beeney has already encouraged some clients to modify combining plans on the basis of the predictions.

Actual Hagberg results are not yet available to determine whether the switches paid off. &#42

HAGBERG FORECAST

&#8226 Early accuracy.

&#8226 Results delayed.

&#8226 NIAB Labtest problems.

&#8226 Limited use in south this year.

&#8226 Northern exercise on-going.

PILOT PROJECT

Rapid ripening and almost uninterrupted progress by southern combines means the exercise has been of limited value this season, admits Mr Cook.

"Local logistical problems meant we were also perhaps a bit late taking the original samples. But we still need the results back sooner." In some cases it took 10 days, by which time fields had been cut.

"Sampling is time-consuming but not arduous," he says. But getting a truly representative sample in partly lodged crops is difficult and could explain some variations.

NIABs John White says the main problem is threshing immature grain. "We also had to reject some samples because they had been taken too early."

He admits the lab was unprepared for the concertina effect of the weather bringing a flood of samples in at the same time. The need for gentle drying of the immature grains which are used in the test caused much of the delay, he adds.

"We have identified the need for some investment, in threshing equipment, for example. We are aiming at a five-day turn-round next year."

Knowing likely wheat quality before harvest could help plan combining and storage, says Mike Dalgarno. But variations within fields remain a problem, he says.