LOW BIOMASS conventional oilseed rape varieties could soon challenge higher yielding hybrids, according to Grainseed.

This follows pleasing performance of the Recommended List newcomer, ES Astrid in trials this harvest, explained the firm’s John Hardy.

Latest Home Grown Cereals Authority (HGCA) results show a mean seed yield of 106% of control – the second highest conventional yield (behind NK Grace, 108%) and above some of the hybrids, he said.

Good multi gene phoma resistance (HGCA rated 8) is a key factor in the yields, particularly in areas such as Bedfordshire, Herts, Essex and Suffolk, where phoma is a major concern, he said.

“Increasingly oilseed rape is being grown tighter in the rotation, which means phoma is causing yields to go down, but the more concentrated it [phoma] is, the better Astrid seems to do.”

ES Astrid also did well in Agrovista trials this year, added trials manager, David Blance. At 6.4t/ha, it was the second highest yielding, 0.1t/ha behind Toccata.

“The high stem canker resistance score should make for simple disease control and the variety’s short habit ensures easy combining,” he commented.

But while the variety is rated 8 for stem shortness and resistance to lodging, Mr Hardy said its main drawback is low oil content – averaging 41.6% in 2005 HGCA trials.

Growers should also not take the Agrovista yields literally, he warned. “The plot-based yields are higher than farm expectations, but they do show trends and the potential for a variety.”