New-generation dwarf durum variety DBA Vittaroi (PBR) is giving growers in southern New South Wales an irrigated cereal option able to hit quality targets and break yield barriers.

The variety features short stature and strong straw, the best forms of resistance against lodging, and has come from the GRDC-invested national Durum Breeding Australia (DBA) program's northern node, in Tamworth.

The program's northern node is led by NSW Department of Primary Industries (NSW DPI) Tamworth-based breeder, Dr Gururaj Kadkol, while the southern node is led by the University of Adelaide's (UA) Associate Professor Jason Able. Both nodes exchange breeding material and run crossing and selection programs.

"Through EGA Bellaroi (PBA) and then DBA Vittaroi (PBA), our germplasm has given the irrigator the best ability to produce the top durum grade of ADR1, and with best management practices," Dr Kadkol says. "DBA Vittaroi (PBA) is yielding as high as 12 tonnes per hectare.".

Profit per megalitre

DBA Vittaroi (PBA) is comfortably achieving yields of 10t/ha, as well as making ADR1 specifications, which include a minimum 13 per cent protein and maximum 5 per cent screenings.

The DBA program has irrigated trials in four locations:

• NSW DPI's Breeza Research Station
• The Irrigated Cropping Council site at Kerang, in Victoria
• Private properties at Spring Ridge and Hillston, in NSW.

Griffith-based consultant Barry Haskins is running the Hillston trial. He says benchmarking undertaken by his AgGrow Agronomy and Research consulting business has shown durum to be the most profitable of all irrigated winter crops.

AgGrow Agronomy and Research agronomist Barry Haskins in a trial of durum wheat at his Beelbangera farm near Griffith, New South Wales. Photo Nicole Baxter

"It's yielding around 2t/ha more than bread wheat and, in dollars-per-megalitre terms, it's continually ranking well above most other crops, both winter and summer," Mr Haskins says.

"Irrigators would be disappointed if they weren't achieving $300 to $400 per megalitre, and durum is commonly at the top end of these figures with the benchmarking we've done."

It's yielding around 2t/ha more than bread wheat and, in dollars-per-megalitre terms, it's continually ranking well above most other crops, both winter and summer.

While bread wheats suited to irrigation are ideally planted in May, durum can be planted in June, which Mr Haskins says makes it an appealing crop to follow autumn-picked Riverina cotton.

Improved nutrition

Dr Kadkol says not all durum varieties are able to put nitrogen into increasing grain protein while maintaining a high grain yield and low screenings, a trait for which varieties from the Tamworth program are selected and developed.

Mr Haskins says this improved genetic feature, when matched with careful plant nutrition management, is delivering the high yields and quality.

"The protein target we set is 13.5 per cent, and levels of 14.5 per cent are common, even in crops yielding more than 10t/ha," he says.

"Going back five or 10 years, we didn't have the runs on the board to grow durum crops like that, as the varieties would lodge if we pushed them too hard with nitrogen. We were always under-fertilising, or applying fertiliser at the wrong time, and that took away the profit that the crop could generate."

Mr Haskins says the improved strategy includes balancing the nutrition plan according to soil tests and paddock expectations, starting with an adequate base level of nitrogen and applying nitrogen at a rate of 25 kilograms per hectare for every one tonne of durum in the target yield.

Irrigation scheduling is also extremely important and Mr Haskins says durum can now capitalise from later water than bread wheat because of its large grain size.

"Agronomically, we've nailed how to grow durum on irrigation, and it can supply a feed market and a durum market," he says.

Acid-tolerance goal

Dr Kadkol says the project is working on adapting durum to soils with low pH and aluminium toxicity to turn it into an option for dryland growers in southern NSW.

NSW Department of Primary Industries durum wheat breeder Dr Gururaj Kadkol checks trials at the Tamworth Agricultural Institute, where advanced breeding lines were being assessed for crown rot tolerance. Photo Nicole Baxter

CSIRO's pre-breeding program, run by Dr Manny Delhaize, which has transferred some aluminium-tolerant genes from bread wheat into durum, is also playing a part.

On acidic soils, durum has traditionally carried a yield penalty compared to bread wheats, and Mr Haskins and Dr Kadkol believe varieties in the pipeline hold promise to narrow the gap. In the northern region, dryland durum is typically grown on clay vertosols with a pH of more than 8.0, which contrasts with the higher acidity of soils in southern NSW.

"With the varieties we have now, durum needs a pH of at least 6.0 to perform well," Dr Kadkol says.

"Our germplasm specifically needs to adapt to lower pH, but we haven't got the results just yet."

DBA is also running additional trials at locations, including Cowra and Beelbangera near Griffith, to identify genetics that can cope with lower pH in dryland conditions.

Broad scope

In the 1940s, the NSW Government started the durum project that has delivered many successful varieties to the grower community - which now extends north and south from durum's traditional heartland on the slopes and plains of northern NSW.

Durum is also a significant crop in South Australia and pockets of Victoria, supported by the southern node of DBA located at the UA, which has bred DBA Aurora (PBA) and DBA Spes (PBA).

DBA Aurora (PBA) is the main variety grown in South Australia, but DBA Vittaroi (PBA) is also starting to be grown in the Mid North and Yorke Peninsula regions.

"DBA is very interested in developing varieties which expand and diversify Australia's durum production area and our ultimate aim is to provide varieties that will stabilise and increase durum production in Australia," Dr Kadkol says.

Australia typically produces 500,000t of durum per year, but very low 2018 production in northern NSW - due to a lack of planting rain - and a dry outlook for 2019, are likely to have reduced the national figure to about 250,000t.

More information: Gururaj Kadkol, 02 6763 1232, gururaj.kadkol@dpi.nsw.gov.au