Combine harcesting oilseed rape© Tim Scrivener

Oilseed rape yields show a near-8% rise in gross output in independent trial sites that established well and were largely free of pests.

Early results show a gross output of 5.7t/ha, above a four-year average of 5.29t/ha, according to three AHDB English trial sites.

“Where crops got off to a good start, established well and were free of pests then the weather conditions suited the crop,” AHDB variety expert Simon Oxley told Farmers Weekly.

See also: Harvest 2015: Top 5 yielding oilseed rape varieties

Gross output is measured by the seed yield adjusted for the oil content, with the Oxfordshire site giving the highest output at 6.16t/ha.

Oil contents for the three trials in Hampshire, Norfolk and Oxfordshire show levels near the norm, ranging from 43.5-45.7%.

All three sites were outside the main hot spot for cabbage stem flea beetle damage – around the M11 corridor – and established well.

The highest yield varieties include Arazzo (111%), Charger (111%), Avator (108%), Fencer (108%), Incentive (108%), Harper (108%), V316OL (107%) and Campus (107%).

Based on four-year averages, the highest yielding varieties to date are V316OL (108%), Incentive (107%), Charger (107%), Campus (106%), Arazzo (106%) and Picto (105%).

The clubroot-resistant variety Mentor had a gross output of 102% compared with the established resistant variety Cracker at 94%.