Novel seed treatments reduce nitrogen use

The legacy of very wet conditions has resulted in thin crops and poor grass weed control, leading to a much higher level of grass weeds in seed crops of wheat. The UK Cereal Certification Scheme offers no safeguards to protect farmers from importing blackgrass, brome grasses, or ryegrass. A 2kg sample of C2 HVS (the highest standard) wheat, barley, or oat seed can contain up to four blackgrass seeds, two brome seeds, and two Italian ryegrass seeds. The C2 lower standard seed can contain up to 28 blackgrass seeds and 18 brome seeds. Once blackgrass is established on a farm, the farmer is in for a life of difficulty. NIAB trials on up to 21 combinations of herbicides showed the best control at 98.6%, reducing blackgrass numbers to just over one per square metre at a cost of £135/ha.

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Winter Wheat in feb Ref:RH020224171 Rob Haining / The Scottish Farmer

Hence, it is crucial that farmers insist on zero tolerance for blackgrass, brome grass, and ryegrass when ordering certified seed. It is worthwhile making this part of the contract. Once seed arrives on the farm, retain 5kg from every batch. In the east of Scotland, we have an excellent seed testing station in Forfar. Peter at Grain & Seed Analysis has provided the GSA price list before VAT:

Full germination: £26 (the aim is to sow seeds with at least 95% germination)

Weed search: £32 (to ensure zero tolerance for grass weeds)

Tetra with vigour: £55 (it is important to sow high-vigour seed)

Full seed health check: £41.50 (very healthy seed may not require a seed treatment)

Today, many seed companies, such as Harleys, use colour separators, which are game-changers. These clever machines can remove 100% of grass weeds, other cereals, etc.

Seed vigour describes the establishment potential of the seed. Some seeds produce higher levels of field establishment under stress – these are high-vigour seeds. In very good seedbeds and with good weather, as long as the germination rate is at least 95%, seed vigour makes no difference to establishment. In extreme weather conditions, such as late sowing into poor seedbeds followed by heavy rain, vigour makes no difference – the crop will fail. But in conditions between these extremes, high-vigour seed can make a huge difference to establishment. Agrii tests seed for vigour, and only high-vigour seed is sold as Master Seed. For home-saved seed, GSA can carry out a vigour test. Be wary of seed treatments that claim to increase seedling vigour – it’s much better to sow naturally high-vigour seed.

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Wheat crops

Certified seed will usually come with an SPD seed treatment, such as Beret Gold, to control seed-borne diseases. A typical price for HVS C2 wheat seed may range from £530 to £590 on-farm with Beret Gold seed treatment. Other options will cost extra:

Vibrance Duo: +£50, increases root vigour

Signal: +£115, essential where there is a risk of wheat bulb fly

Latitude: +£210, the only effective treatment to control Take-All

Manganese: +£45, important on light soils to control Mn deficiency

Novel new seed treatments

Nuello iN is a seed treatment that contains nitrogen-fixing endophyte bacteria. My friend Alison Stewart, the Scots-born CEO of the Foundation of Arable Research in New Zealand, did her thesis on endophyte bacteria and believes these show real promise. Consider that a wheat plant grown from treated seed can uptake an extra 30 kg of nitrogen from the atmosphere. These products can be game-changers in reducing the need for applied nitrogen and lowering our carbon footprint.

At £70/t, this could cost the farmer an extra £13/ha. However, 30 kg of nitrogen may cost £26.

In a world where regulations limit the amount of nitrogen farmers can apply, and the market rewards farmers for lowering their carbon footprint, these products are well worth on-farm field-scale trials.

Variety choice for wheat

The lesson from last season is to grow varieties that are not only very high-yielding but also have good genetic resistance to septoria. The latest AHDB 2024 yield results are promising, with percentages over the mean yield of 10.8t/ha.

Soft wheat for distilling

Bamford, 110%: Looked very well in trials. Seed is scarce, but grab some if you can.

LG Redwold, 110%: Do not sow early; very vigorous and will smother grass weeds.

KWS Zealum, 101%: A better option than LG Skyscraper, won 1st prize on my neighbour’s farm.

Hard wheat for feed

Champion, 112%: Looked fantastic, with no need for expensive fungicides.

KWS Extase, 108%: Not suitable for Scotland; too far north, and ear sterility is a real threat.

Graham, 108%: Still going strong, good for early sowing and an early harvest.

LG Typhoon, 105%: Ideal for early sowing.

Ear sterility in wheat can be a problem the further north one farms, so the north of Scotland is more prone than Yorkshire.

When night-time temperatures fall rapidly between stem extension and flag leaf, the ears of wheat may have fewer grains at harvest. We are currently waiting for more information on Bamford and Champion. As with any new variety, try a small area first, or consider a 3-way blend to reduce risks. NIAB is testing several wheat blends to determine the best mix.

Winter barley

Six-row hybrids have extra vigour and can smother grass weeds. For Scotland, there is only one option: SY Kingbarn. In Scotland, increase the seed rate by 20%. Two-row varieties: LG Caravelle in NIAB trials equalled SY Kingbarn for yield. However, if grass weeds are an issue, or if you want a large crop of straw, which today is worth £100/t, grow SY Kingbarn. Another two-row variety that has produced quite high yields is KWS Tardis.