A new Dekalb hybrid oilseed rape variety was trialled by several Farmers Weekly growers this season alongside regular crops. In the last of our series, Philip Case looks at harvest

Winter oilseed rape newcomer DK Expower performed well in trials this year, growers agreed, but some saw little difference in performance compared with the main existing varieties.

Expower proved to be Leicestershire grower Keith Challen’s highest-yielding rape variety this season at 5.4t/ha, ahead of Cabernet 4.5t/ha and ES Astrid 3.9t/ha.

“We are on some very heavy land and the drought has not bothered us. It has retained the moisture,” he said.

“We kept the crop fed well with liquid nitrogen. We got plenty of boron on early in the season and we used some phosphate as well had a big part to play to build yield.”

For next year, Expower will command a third of Mr Challen’s rape acreage with two other varieties out of the same Dekalb stable – Excellium and Extrovert – making up the rest.

Similarly impressed was Humberside Barometer Farmer Jonathan Fenwick, where Expower will command 20% of his total rape acreage in 2012 – double this years amount.

“The Expower was a long time ripening, but it was clean. It was easy to harvest and I’d give it a full score for that,” he said.

Expower yielded 5.2t/ha, giving it the edge over Excalibur and Excel, which both yielded around 5t/ha. But it was beaten by the hybrid Dimension and semi-dwarf variety DK Sequoia, which both yielded 5.6t/ha.

However, Lincolnshire grower Will Howe said his Expower and Excalibur performed similarly, yielding 4.6t/ha and 4.7t/ha, respectively.

“The Expower performed well, but it didn’t break any records,” he said. “But it’s a variety I’d like to keep an eye on and compare with Excalibur.”

Expower was not as easy to combine, though. “It was a bit taller and stood greener in the straw, which slows you up in the combine.”

He also found germination problems with Expower. “We planted it at 70 seeds/sq m, but in places it only had 12 seeds/sq m come through.”

He was still prepared to give Expower another go and has planted a larger area for next year. “It’s already in the ground. We’ve got 50ha – about one-third of my total oilseed rape area.”

Fellow Lincolnshire grower Tony Reynolds also saw little difference. He grew two conventionals – 42.5ha of Alienor and 5.4ha of Sesame – alongside two hybrids – 2.5ha of Excalibur and 1ha of Expower with 1ha of each variety grown alongside Expower to give the trial maximum potential.

All four varieties yielded around 4.4t/ha, but Alienor was marginally better. “Alienor yielded more than we thought,” he said.

No pod shatter resistant products were applied to any varieties, but the Expower pods appeared firmer than the others.

“The Expower was shorter and had a lower biomass than the others. It stood well and was easy to cut, with less shed pods than the average,” said Mr Reynolds.

The driver suspected that given a larger area, Expower would have outyielded the others. “He felt it had better crop potential, but 1ha was not enough.”

However, the Expower did not demonstrate enough of a difference to persuade him to change his three main varieties for next season.

Kent grower Andy Barr, grew a small portion of Expower alongside 116ha of Excalibur. He too found it hard to split the varieties.

His Expower marginally outperformed Excalibur, yielding 4.2t/ha compared with 4.1t/ha. Oil content for both varieties was 44.5%.

Both varieties were similar in the field, but the Expower had more biomass.

“The main difference with Expower was there was more of it. It lodged in places, whereas the Excalibur didn’t.” he noted.

“The Expower, with its hybrid vigour, got away quickly in the autumn and spring, but the Excalibur eventually caught up.”

He reckoned that Expower, with its improved disease resistance profile according to trials data, could be the way forward.

“In a high disease pressure year, maybe it would come through a bit stronger,” he said. Next season, he plans to drill 25ha of Expower in his total rape acreage of 100ha.

However, Cambridgeshire grower Edd Banks had to pull up 1.5ha of his 5ha trial plot of Expower after he drilled it late and the crop suffered from poor establishment on light soils.

• Seven regular Farmers Weekly contributors were among 44 growers who trialled the new Dekalb hybrid Expower, as well as the variety DK Exstorm, which none of our contributors opted for.