Management of milling wheat

Milling wheat management needs a unique approach. From variety selection and agronomy to harvest and storage, attention to detail is the key to growing success.

Milling crops can be grown as a first or second wheat.

First wheats offer several benefits, especially relatively low levels of soilborne disease and high levels of residual soil nitrogen.

Green bridges (e.g. via annual meadow grass and volunteer cereals), which can potentially transfer BYDV-spreading aphids to new cereal crops, also tend to be less problematic following a non-cereal crop.

Variety choice and nitrogen management are particularly important to reduce the protein-dilution effect associated with the higher yields of first wheats.

The Recommended Lists for cereals and oilseeds (RL) provides information on the performance of milling varieties ordered within four end-use groups.

Grain protein content is critical in milling wheat. It is positively related to grain nitrogen levels.

Although nitrogen levels are highly influenced by genetics (i.e. varietal choice), nitrogen availability to the crop is also extremely important.

As a result, nitrogen needs careful management, especially in bread-making wheats, which require relatively high rates.

The need for carefully targeted nutrition is particularly important when nitrogen prices are high (such as seen in 2022 and 2026).

It is also important to consider factors that constrain yield (without affecting nitrogen transport to the grain) and increase grain protein levels. Such factors include weather (e.g. drought and lodging) and some diseases.

Sulphur deficiency can impair nitrogen utilisation.

It is important to make sure the crop receives adequate amounts of sulphur to build yield and achieve grain quality.

Sulphur-deficient wheat is also associated with an increased risk of acrylamide formation (a processing contaminant) during high-temperature cooking and processing of wheat-based products.

There are no special recommendations for other major crop nutrients (phosphorus and potassium) or micronutrients for milling wheat in the AHDB Nutrient management guide (RB209).

However, it is particularly important to avoid copper and selenium deficiencies, as:

• Copper-deficient soils may produce grain that results in greater variability in bread quality
• Selenium is generally low in soils in many parts of Europe (including the UK), but the nutrient is essential in human (and animal) health

Diseases that impact the quality or condition of grain require closer attention in milling wheat crops.

Infection by fusarium and microdochium species can lead to various symptoms, such as poor establishment, ear blights and lower yields.

The production of toxic mycotoxins (to humans and animals) in the grain by some fusarium species is the main concern.

In wheat, key fusarium mycotoxins include deoxynivalenol (DON) and zearalenone (ZON).

It is important to follow best practice to keep levels below limits, which includes the completion of a risk assessment (see Combinable Crops Passport section), where necessary.

Mycotoxins are also produced in the field by ergot (ergot alkaloids).

The main fungus in stored grain is Penicillium verrucosum.

The pathogen is active at a wide range of temperatures and produces ochratoxin A (OTA).

Permitted levels at intake for grain destined for human consumption can be exceeded in under two weeks, especially when grain moisture content is at or above 18%.

In addition to fusarium head blight and ergot, other ear and grain fungal species can impact grain’s appearance and acceptability to millers (e.g. sooty moulds and bunts/smuts).

Many foliar diseases can also spread to ears/awns and taint grain, such as rusts and powdery mildew.

Insect feeding activity can also damage grain and make it unacceptable to processors.

The feeding of orange wheat blossom midge larvae can:

• Result in small and shrivelled developing grains
• Damage the outer grain layer (pericarp)

Grain with damaged outer layers is more vulnerable to fungal infection (e.g. fusarium and septoria) and allows water to enter (which can cause premature sprouting).

Although grain aphid can spread Barley yellow dwarf virus (BYDV) in cereals, it also causes direct feeding damage and indirect damage by secreting sticky honeydew during feeding.

This sugar-rich liquid encourages sooty moulds to develop and provides a sugar source for flies, including some pest species.

Milling wheat is a food product and requires the highest standards of handling and storage.

As the crop reaches maturity, adverse conditions (wet, cool and windy weather) can severely impact crop quality. For example, by increasing:

• In-field mycotoxins
• Frequency and severity of lodging
• Pre-harvest sprouting

The latter two can reduce Hagberg Falling Numbers (HFN).

When weather is unfavourable, prioritise the harvest and drying of premium crops, such as milling wheat.

Drying costs are often offset by premiums secured, especially when the general quality of the UK crop is low.

Glyphosate is sometimes used before harvest to even up and speed up crop ripening to facilitate combining.

However, it is no longer permitted for preharvest/desiccant use in the EU, which applies to Northern Ireland (pre-harvest use for weed control is still permitted).

Use is permitted in GB, providing the product label lists desiccant as an authorised use.

Discover the insect and mite species that are commonly found in stored grain, including those that damage grain directly and indirectly (mould or hygiene issues), as well as the species that cause no damage.

See the signs of defects and impurities in stored cereal, including physical damage, disease, pests, screenings and weed seeds.

Learn how to take samples to provide a robust, representative record of the quality and condition of all the grain that leaves your farm.

From store preparation to final dispatch, our grain storage guidance illustrates how to identify and manage hazards/risks and details the main grain storage targets (e.g. for moisture, temperature and cooling).

Don’t forget: the grain seller needs to supply an appropriately completed and signed Combinable Crops Passport with every load collected/delivered.