A revised AHDB Harvest Progress Report shows UK wheat yields are down 3.5% on the five-year average, correcting an earlier, more optimistic 1% drop.

The revised report, for the week ending 6 August, shows yields averaging 7.46t/ha – 3.5% below the five-year average of 7.73t/ha – though variability remains high.

The AHDB noted the five-year average includes two poor years, 2020 and 2024. Compared with the 10-year average of 8.1t/ha, 2025 wheat yields are 7.2% lower.

See also: Farmers Weekly Podcast Ep 267: AHDB harvest error triggers investigation

The initial report, published on 8 August, sparked an outcry among farmers, of whom many have struggled with a difficult harvest season marked by drought and challenging growing conditions.

Some growers are reporting yield declines of a third or more.

The Andersons Centre, which provides the data to the AHDB, admitted to a data error and is conducting an internal investigation.

A spokesman told Farmers Weekly: “There was a mistake in the data. We have identified and addressed it. We will publish the next harvest reports this week with the corrected figures.”

The original report, released with just under half the wheat harvest completed, sparked farmer questions on social media about data accuracy and whether growers had been properly consulted.

The data showed only a 1% drop in wheat yields compared with the five-year average, despite an earlier report covering up to 23 July – when only 10% of the crop was harvested – indicating an 11% decline.

AHDB apology

The AHDB acknowledged the error following feedback from growers and the industry. A spokesperson said: “We recognise the pressures cereal farmers have faced this year, with extreme weather and rising costs. We apologise and remain committed to transparency.”

Regional variability

Speaking to the Farmers Weekly Podcast, NFU Combinable Crops Board chairman Jamie Burrows said a 1% average yield drop certainly did not reflect the experience of many cereal farmers this season, although there was significant regional variability.

“It’s so variable, even locally. Some farmers in Cornwall and parts of Wales have had their best harvests ever as they have had regular rainfall… but the majority are just not anywhere near average,” he added.

“I’m sure in the cross-section of farmers that Andersons/AHDB have looked at, they must be about right. It’s just that it’s not giving a full representation of the whole of the UK, in my opinion.”

The report provides early insights into crop size and quality, helping growers with marketing decisions and processors with supply planning.

The AHDB will review its processes with Andersons to ensure future reports are accurate. The next update is due today (Friday 22 August).