Growers exploit weather extremes to hit record OSR yields
© Tim Scrivener Oilseed rape growers’ ability to exploit weather extremes has been cited as a key factor in record-breaking yields last season.
Lincolnshire grower Tim Lamyman reclaimed the oilseed rape yield world record after producing 7.7t/ha in the 2025 season.
The achievement came during what was described as one of the driest growing seasons on record.
See also: Adas to pull plug on cereal and oilseed YENs
“The fact that three British OSR growers surpassed 7.5 t/ha is a testament to their skill in exploiting weather extremes,” said Adas head of crop physiology Pete Berry.
Speaking at the UK Yield Enhancement Network Conference (YEN) in Peterborough, he noted early-season conditions played a key role: “October 2024 was warmer than average for almost all of the UK.
“This was followed by a winter without excessive rain and a very sunny March and April.”
Long-term data support this pattern, said Dr Berry.
“Looking at weather data and yields dating back to 1976, this seasonal pattern has been conducive to higher-yielding years for OSR – but growers need to be ready to exploit them.”
Cereal yields
In contrast, cereal crops experienced yield reductions in 2025.
Warmer conditions shortened growth stages, while drought stress at flowering reduced grain numbers.
“With the wheat crops submitted into YEN every year, we have seen the average grain fill period decrease by several days since 2013 as a result of warmer conditions,” he said.
He added that these impacts were “often compounded by factors such as a lack of water, insufficient nutrients, and incomplete disease control”.
The conference marked the conclusion of the Cereal and Oilseed YENs being run by Adas after 13 years.
YEN founder Prof Roger Sylvester-Bradley said: “The YEN has proved hugely successful,” adding that it has helped growers better understand yield gaps and crop potential.
Founded in 2012, YEN has supported farmers across the UK and north-west Europe in benchmarking crop performance and analysing yield potential.