Expectations of hefty UK wheat imports, potentially even from the US, strengthened as farm officials confirmed the dismal domestic harvest, pegging yields at the lowest in 20 years, hurt by pressures from "high levels of disease".

The poor quantity, and quality, of the UK wheat crop, coupled with demand spurred by the opening of bioethanol capacity, could see imports "rise as far as 2.5m tonnes, or higher", Jonathan Lane, trading manager at merchant Gleadell said.

"Import amounts continue to rise as millers turn to imports to blend or replace UK supplies," he said, adding that imports of 2.5m tonnes would be "a figure not seen for many years", besides one which has constrained milling premiums despite the weak harvest.

Separately, the HGCA crop bureau, in its first estimate for the UK wheat balance sheet, pegged imports in 2012-13 at 1.7m tonnes, while estimating the country's exportable surplus at, at best, 750,000 tonnes.

"This is an historically low surplus and sugggests very limited export availability," the HGCA said.

The UK has not been a net importer since 2001-02. Last season,  wheat imports in 2011-12 came in at 867,000 tonnes, well below exports of 2.39m tonnes, customs data show.

'Mills have been struggling' 

The idea of significant imports was also flagged by UK grain traders at a major European commodities house, who highlighted talk over the trouble that mills were having generating flour from a poor quality domestic crop.

While lowering to 70 kilogrammes per hectolitre, from 76 kilogrammes per hectolitre, their hurdle rate for specific weight – a key quality metric – they will take for top grade wheat, mills "have been struggling" with the grain.

They have reportedly been "running flat out for 24 hours a day but still are unable to produce enough flour for their customers due to the very poor extraction rates", the traders said.

With German milling wheat "available delivered into the northern mills at about the same price as full spec Group 1s, and with consistent quality and specific weights well over 76 kilogrammes per hectolitre, It's no surprise that millers are turning to this better material".

Imports from the US? 

For Group 3 milling wheat, used in making biscuits, the dearth of supplies may even force millers to turn to US supplies, they said, echoing comments made by US broker Benson Quinn Commodities last month.

"The only alternative is US soft red winter wheat," the type traded in Chicago, which is "less than £20 tonne above our Group 3 prices delivered into the northern mills", the traders said.

"Again, with its better quality it may already be a viable option and we have to remember that once the decision is taken, it turns up in cargoes of 25,000 or 50,000 tonnes."

'High levels of disease'

The comments came as Defra, the UK farm ministry, in its first estimates for the 2012 harvests warned that "yields for all [major] crops have fallen between 2011 and 2012, with wheat and oilseed rape showing the greatest drops", after the wettest summer in a century.

In wheat, "yields have been affected by the poor weather, which led to high levels of disease during spring and summer along with low sunlight levels during the grainfill period".

The wheat yield of 6.7 tonnes per hectare was the "lowest it has been during the last 20 years", with the harvest pegged at 13.3m tonnes, a 13% decline year on year.

The production figure is in line with a 13.25m-tonne estimate last week from the National Farmers Union, with Strategie Grains on Friday putting the crop at 13.4m tonnes, and the US Department of Agriculture on Thursday putting the crop at 14.0m tonnes.