Tips to maximise winter barley yields
©Tim Scrivener
High yielding feed barley varieties that can favourably compete in the rotation have led to a 4% increase in the area of winter barley grown in England and Wales in 2015.
And this AHDB figure is expected to rise again this autumn, but many growers are failing to get the most from the crop and industry experts believe they can raise yields by tweaking on farm agronomy.
Early growth, tiller production and retention are crucial to producing the highest yields, explains Scotland’s Rural College’s crop science team leader Steve Hoad.
See also: Changes to winter barley fertiliser plan drives yield to four-year high
The best conventional barley crops come from an initial target population of 300 plants/sq m and several shoots per plant.
Hybrid barley
Hybrid barley now accounts for 20% of the winter barley area in the UK and promises a yield advantage of up to 1.0t/ha over conventional varieties.
But there are some important management practices that must be adopted to get the best from the hybrid crop, say experts.
Seed rate is critical and this cannot be emphasised enough, says Syngenta’s James Taylor-Alford.
“People still use too high a rate which results in too many tillers and too many ears. Specific weight suffers and that can drag down yields especially if you get a delay in harvest.”
His advice is to aim for 180 plants/sq m in the spring when drilled in mid-September and to apply early nitrogen to stimulate tillering.
“The current recommendation is to apply 30% of the nitrogen at GS25 in mid- to late-February when the crop is actively growing, 50% of the main dose at GS30 and then the remainder at GS32/33,” explains the firm’s James Marshall-Roberts.
Even where crops are thick and well tillered he still advocates applying the nitrogen early, as delaying can result in more secondary tillers, affect grain quality and produce a more conventional level of yield.
As with all winter barley the T1 fungicide timing is critical as barley is sink-limited, so if spikelet survival is compromised then the formation of grain sites will be decreased.
Therefore, robust rates of SDHI, triazole and strobilurin chemistry all have a place at this timing, he says.
Yet over the past couple of years, trials have demonstrated a clear benefit from the T2 on yield, specific weight and brackling, putting almost equal emphasis on this timing.
“Even in the absence of disease we are seeing the benefits, especially in brackling.” Therefore, Mr Marshall-Roberts advises to ensure that T2 is not omitted even in a low-disease year.
“You don’t need the highest rates, but it is worthwhile having a robust T2 whether it is a combination of triazoles, SDHIs and strobilurins or just SDHIs and triazoles.”
Growth regulation is very important too. Early applications of chlormequat (at, GS25-30, help the below ground structure with rooting and tillering, while Moddus + chlormequat at GS31/32 addresses stem thickness and a later application of Terpal helps to reduce height, he adds.
Even establishment is crucial because, unlike wheat, barley is less able to compensate by increasing grains per ear if the establishment is poor, he says.
“Higher tillering [two-rows] or higher ear weight [in six-rows] offers an opportunity to reduce seed rates, perhaps down to 300 seeds/sq m, but it needs to be adjusted based on experience of ear size and yield.”
Raising seed rates doesn’t tend to equate to a yield benefit, but will give more shoots producing fewer seeds per shoot, increasing screenings and reducing specific weight.
Drilling date
Dr Hoad suggests an optimum sowing date between the middle and end of September.
Drilling too early runs the risk of excessive winter growth and a higher lodging risk, plus the increased risk of early barley yellow dwarf virus infection. Going too late means there is less time for the plants to produce sufficient tillers and you might compromise on your final ear populations, he cautions.
To maximise yield the crop needs as many tillers as possible, and early nitrogen before stem extension is key, says Adas principal consultant Pete Berry.
This early timing depends on the region. In the South, it will typically be the end of February, and in northern regions the start of March.
“Current RB209 advice recommends 25% of the nitrogen is applied before stem extension, but our work indicates it might be better to put as much as half before the start of stem extension.”
The rest of the nitrogen should then be applied at GS30/31.
This early nitrogen approach reduces the risk of secondary tillering and often reduces grain nitrogen by 0.1%, he adds.
But Dr Berry cautions against going too early on shallow soils and in high rainfall situations and running the risk of nitrate leaching before the crop has taken it all.
Higher N rates
Recent research suggests that optimum rates for feed winter barley could be as high as 250kg N/ha where soil residual N is low and yield potential is 10 t/ha or more.
A review of trials data funded by AHDB has shown that higher yielding crops needed 27kg N for each additional tonne above 8t/ha compared with RB209 recommendations. The main objective of the AHDB-funded work, led by Adas, is to provide evidence for revising RB209 recommendations.
As long as nitrate vulnerable zone and N-max rules are met, a Facts-qualified adviser is consulted, and growers have evidence of historic yield data, higher rates can be applied, he adds.
Where the total applied nitrogen is more than 200kg/ha, Dr Berry advises three splits, as long as 50% is applied before GS30.
Growers in agronomist Steve Cook’s area in Hampshire have been rewarded with excellent yields by adopting an early nitrogen regime and a robust fungicide and growth regulation programme.
“With barley you have to set up the yield early and it has to be clean to get the bigger heads. Then you have to fill them.”
Disease strategy
He only advocates a T0 if the crop has early mildew or brown rust infection or if there is a lot of rhynchosporium coming out of winter.
“This will help to keep the main timings right. Otherwise, T1 at GS31 is definitely the most important, as lower leaves contribute more to yield, the size of the ear and number of grains,” he says.
Actives
- Adexar – epoxiconazole + fluxapyroxad
- Bontima – cyprodinil + Isopyrazam
- Cerone – ethephon
- Corbel – fenpropimorph
- Cycocel – chlormequat
- Moddus – trinexapac
- Proline – prothioconazole
- Siltra – bixafen + prothioconazole
- Terpal – ethephon + mepiquat
“If you lose disease control on winter barley you lose yield from the beginning and it is difficult to get it back.”
That said, a T2 at the awns-emerged stage is still important and even in lower disease situations a good T2 is necessary.
“If you’ve set up the yield potential by getting it right early on, why waste it later with something that is relatively cheap and will give a yield response in the absence of disease.”
Product-wise, Mr Cook chooses to use a 60% dose of Siltra at T1 and a 40% dose at T2. The key is a good SDHI + prothioconazole, the choice of SDHI doesn’t matter as much, he says.
It is maintaining the gap between T1 and T2, which shouldn’t be more than a three-and-a-half weeks to stop rhynchosporium coming in, that is very important and that may mean growers need to be prepared to put an extra holding spray between T1 and T2, which could be a cheap triazole, he says.
Growth regulation is also more important when applying nitrogen earlier, and Mr Cook suggests and a chlormequat + Moddus early, then Terpal at GS32/33 for height reduction.
“The earlier it [Terpal] goes on the better the effect,” he concludes.
Nigel Durdy, Doncaster, Yorkshire
Neil Durdy ©Jim Varney
Doncaster grower Nigel Durdy returned to growing winter barley last season after a break of several years, primarily to meet the three-crop rule.
Positioned in the second and third cereal position, he needs barley to yield at least 7.5t/ha and fetch a minimum of £100/t for the crop to remain viable in the rotation.
And this year’s yields from KWS Cassia, KWS Glacier and Volume didn’t disappoint, ranging from 8.5 to 11.1t/ha over sandy to medium soils.
Yields at the upper end were from the hybrid, Volume, which delivered an additional 1.2t/ha over the conventional varieties, performing exceptionally well on the lighter land, he says.
Mr Durdy attributes this year’s bumper barley crop to the excellent weather conditions in the spring, combined with a keen attention to detail on inputs.
Aside from the different seed rates, 350 seeds/sq m for conventional and 200 seeds/sq m for the hybrid, all the barley was drilled in the last week of September and treated the same in terms of nitrogen and fungicide inputs.
“Barley needs managing early,” he says.
He applied nitrogen in two almost equal splits – the first with sulphur, which he believes is important for the crop, when the barley was beginning to move out of the winter, and the balance as urea at stem extension.
A robust three-spray fungicide programme, which included manganese at each timing last spring, included a Corbel + Moddus + Cycocel at T0, a Bontima + Proline + Moddus + Cycocel at T1 and Adexar + Cerone at T2.
With a lower spend than a second wheat and a better tolerance of blackgrass on the heavier soils, Mr Durdy believes that his barley is performing better than second wheat, with average yields of 10t/ha at £130/t.
That is why barley will stay in the rotation for a while and he will increase the area of hybrids this autumn to reflect the success on the more marginal soils.
