Triticale’s suitability for bioethanol production is up for debate after the release of an ADAS report.
Using triticale instead of wheat as a feedstock for bioethanol production can reduce the greenhouse gas emissions associated with the overall biofuel process by almost 14%.
That’s the main finding of an HGCA-funded report assessing the performance and potential of modern triticale varieties and their value for the bioethanol market.
Richard Weightman of ADAS, who co-authored the report, says that triticale produces lower GHG emissions than wheat, giving the crop scope for meeting future biofuel accreditation schemes with tight emissions or carbon-accounting targets.
“The lower nitrogen requirement of triticale is the main reason for its better performance on GHG emissions,” he says. “It may be slightly lower yielding than wheat in many situations, but it does have better environmental credentials.”
Very high yielding first wheats also rate well as a bioethanol feedstock, because high yields also maximise GHG savings, he adds. “But they have to be grown with the lowest nitrogen inputs possible.
“The benefits fall off once you move to second and third cereal situations, when yields decline and nitrogen inputs are often increased. This is where triticale becomes particularly valuable.”
Cereals, in general, have a good story to tell compared with other feedstocks on carbon accounting, Dr Weightman reports. “And triticale, with its reduced nitrogen fertiliser requirement, offers an opportunity to produce bioethanol at lower economic and environmental costs.”
These environmental credentials could become even more relevant once carbon reporting of biofuels is introduced, he believes.
That reduced need for nitrogen fertiliser saves growers 70-80kg/ha of N, calculates Dr Weightman. “Given the price of nitrogen at the moment, that’s a very good cost saving. High input and energy prices have prompted much closer attention to costs, so a second period of them in the future will see the balance shift again.”
Another reason why growers might want to take a closer look at the crop is that the varieties have come on considerably since the first ones were introduced in the 1980s, he notes.
“Triticale has always been associated with poorer, marginal land. But when today’s varieties are grown in decent soils, yields of 9t/ha can be achieved. That makes them very competitive with second and third wheats, especially where take-all is a problem.”
Triticale has a soft grain, similar to the soft wheats preferred by the distilling industry, which is required for good alcohol yields, he adds.
“In our studies it gave alcohol yields (litres per tonne of grain) comparable to those of Istabraq – a known distilling wheat variety – at equivalent grain protein contents. Certain varieties showed better-than-expected alcohol yields.”
For the report, Dr Weightman and his team looked at 20 samples of triticale, representing 13 different varieties. Each was assessed for grain size, hardness, starch and protein content, as well as alcohol yield.
Varieties giving the best alcohol yields included Grenado, Fidelio and SW Fargo, all of which are on the HGCA Descriptive List for 2009/10.
“As with wheat, there was variation in grain size and diameter. But there were similarities – we’ve always known that Riband achieves high alcohol yields through having large, well filled grains – so too does Fidelio.”
Triticale does tend to have higher viscosity than wheat, he reports. “That needn’t be a problem with biofuel production, as enzymes can be used to deal with it.”
Chris Green of Senova says there have been some significant developments in triticale varieties, making the crop easier to grow than is often perceived.
“We now have shorter, stiff-strawed types,” he says. “It means they can be grown on more fertile sites, without any lodging issues – many of them now have viscosities similar to those of soft wheat.”
Fidelio was the first of a generation of semi-dwarf types, but it has now been joined by varieties such as Grenado and Borwo, which have lifted yields and grain quality further, he explains.
“Borwo is the highest yielding variety on the Descriptive List at 110. Grenado is the shortest variety, with excellent standing ability and good specific weight. They can give continuous wheat some serious competition.”
The crop should be sown before the end of October at a seed rate of about 150kg/ha. Nitrogen use on the stiffer strawed varieties is about 170kg/ha, with first applications being made in late February, followed by the remainder before first node.
As a minor crop, it isn’t scored for disease resistance on the Descriptive List, points out Mr Green. “But that information is available – Grenado, for example, shows good resistance to both brown and yellow rust.”
Nick Oakhill from Glencore Grain , wheat supplier to the Ensus bioethanol plant in Teesside, thinks the UK is unlikely to go down the triticale route at the moment. “There is little value in using triticale over wheat and UK plants have not expressed an interest in the product.”
Wheat’s higher yields and marketability are also more attractive to growers, says David Sheppard, managing director, Gleadell Agriculture. “Triticale only has one market, compared with several for feed wheat, so I can’t see it taking off with growers.”
However, Sweden, Canada and South Africa are all using triticale as a bioethanol feedstock.
The Swedish company Agroetanol opened its first plant in 2001, using a blend containing 40% triticale to produce 55m litres a year. Further investment is taking capacity up to 200m litres, with growers being paid on the starch content of the grain.
Elsewhere, the Canadian government has just announced a $15.5m investment in the Canadian Triticale Biorefinery Initiative, which is a 10 year programme to develop triticale as a dedicated biorefining crop.
And in South Africa, spring triticale is the focus of a four-year contract between Stellenbosch University and PlantBio, with the aim of producing the crop for bioethanol production in the Western Cape.
Triticale Pros and Cons
- Lower greenhouse gas emissions than wheat
- New higher yielding varieties available
- Lower nitrogen requirement
- Slightly lower yielding than wheat
- Bioethanol is the only market
- Little interest from UK plants at present