Assessment of milling wheat varieties

Discover how our Recommended Lists (RL) trials provide information on milling wheat varieties to target the requirements of domestic and overseas milling markets.

Bread-making and biscuit-making wheat varieties need to meet minimum grain quality specifications for milling.

Some of these are associated with highly heritable characteristics (strongly influenced by genetics), which are assessed in RL wheat variety trials:

• Grain protein content
• Hagberg Falling Number (HFN)
• Specific weight

Some RL trials are managed to provide specific milling information, which includes trials that produce very high-quality grain to test general milling and baking performance.

RL trial results help categorise milling wheat varieties by their suitability for domestic (UKFM end-use groups) and export markets.

Note: The RL provides information on all the main market options, including distilling potential.

Although many aspects of trial management are similar across the RL wheat trials, there are some critical differences for those that provide data on milling characteristics.

For example, we:

• Select sites known to produce grain to high milling specifications
• Grow varieties as a first cereal to reduce disease pressure (e.g. take-all) and make sure soils have a relatively high level of residual nitrogen
• Apply extra nitrogen in some trials

The main winter wheat trials test all recommended and candidate varieties in a fully randomised design.

The AHDB Nutrient Management Guide (RB209) is followed in all RL trials.

For most wheat trials, nitrogen rates aim to maximise the yields of feed varieties.

Some trials are managed as bread-making (target 13% protein) and biscuit-making (target 11 to 11.5% protein) wheats.

To grow varieties to bread-making specifications, extra nitrogen is required.

This is also applied in line with RB209 guidance, which means the use of granular nitrogen products during stem extension (about GS37) and/or a liquid foliar nitrogen spray during the early milk stage of grain development (GS73).

As biscuit-making varieties require lower protein than for bread-making, they are managed for optimal yield, with no late additional nitrogen applied.

These trials provide specific information on milling characteristics.

For example, the results from the bread-making trials are used to populate the ‘Protein content (%) – milling spec’ line in the RL winter wheat tables.

We also grow a special set of large plots to provide high-quality spring wheat and winter wheat grain samples for use in small-scale milling and baking assessments.

These cover:

• Grain protein content
• Hagberg Falling Number (HFN)
• Specific weight
• Grain hardness
• Other flour and baking property tests

Usually located in Eastern England, the trials test recommended and candidate bread-making and biscuit-making varieties.

These plots are harvested at their optimum maturity state (rather than at a single timepoint) to ensure grain quality is at its best.

In addition to UKFM group recommendation decisions, the results inform variety-specific comments on quality, which include information on whether a variety fully or partially meets agreed specification values.

Some recommended varieties are initially added to the wheat lists with a ‘provisional’ UKFM group status.

Further milling and baking tests on commercial quantities of such varieties (following a protocol set by UKFM and BSPB) determine whether they should achieve ‘full’ status.

This usually occurs in the spring following provisional recommendation.

The samples from the special plots are also used to assess the potential of varieties to meet the AHDB export classifications.

Cereal crops vary in their susceptibility to ergot (which produces mycotoxins).

From the most to least susceptible: rye, triticale, spring wheat, winter wheat, barley and oats (infection of oats is rare).

As information on varietal risk is limited, it is not included on the RL.

However, higher-risk varieties tend to:

• Be open-flowering
• Have a long flowering period
• Produce late tillers