WITH AROUND 80% of the Scottish winter oilseed rape crop now in the barn, yields have proved disappointing, according to the Scottish Agricultural College.

Average yields are close to 3.4t/ha, which is about normal in Scotland, but slightly below expectations after reports of good yields further south, said SAC’s Elaine Booth.

The poor performance could be due to wet conditions last autumn and winter which resulted in poor establishment, she said.

“It [wet weather] also let disease into the crop – light leaf spot likes cool, wet conditions, so it thrived. It was also difficult for farmers to get on with sprays.”

Dull weather in July – the main time for pod fill –meant crops did not fill seeds as well as they could have done and may be responsible for more small seeds this harvest, she added.

Results of SAC trials found that Elan, Fortis and Winner all performed well, while Lioness appears to have done better in Scotland than further south, Dr Booth said.

“Elan – which is the only variety we have with an 8-rating for light leaf spot – was over 1t/ha higher yielding than Winner in untreated and all treated plots. Royal also had quite a good year.”

More varieties with better disease resistance ratings are needed, but at present the best newcomer – Verona – is rated 7 for light leaf spot, below Elan, and is also very tall and late, she said.

For a roundup of harvest progress nationally and in your area, visit FWi’s Harvest Highlights.