New variety a disease-resistant game changer

On the cricket pitch, when a bowler sends down a ‘seamer’ it is considered a winning delivery due to the difficulties it presents for the batsman.

In the paddock, plant breeders are hoping a new variety of chickpea called PBA Seamer will also prove a game changer for growers.

The new desi chickpea variety has the highest resistance yet to the fungal disease ascochyta blight and was developed by GRDC-supported research partners: the New South Wales Department of Primary Industries (NSW DPI) and Pulse Breeding Australia (PBA).

PBA Seamer, which will be available for sowing in 2017, has a cricket moniker to match the naming theme of other chickpea varieties, such as Howzat, Yorker, Flipper, PBA HatTrick and PBA Boundary.

The pulse-breeding project led by NSW DPI researchers had trial sites across the GRDC’s northern grains region, including Queensland, which saw Queensland Department of Agriculture and Fisheries (DAF) researchers also contribute to the PBA Seamer trial data.

Queensland DAF senior plant breeder Merrill Ryan, who works on the PBA program at the Hermitage Research Station, predicts the new variety will be a “game changer” because it has high disease resistance and northern growers are likely to face high disease pressure this season.

Photo of Queensland DAF plant breeder Merrill Ryan

Queensland DAF plant breeder Merrill Ryan says this is the first time growers have had a chickpea variety with an ‘R’ (resistant) rating to ascochyta blight fungal disease.

PHOTO: Toni Somes

"Ascochyta is the biggest issue facing chickpea growers, so PBA Seamer’s superior resistance to the disease is very significant. This is the first time we have been able to give a chickpea variety an ‘R’ (resistant) rating,” Dr Ryan says. “Under very high ascochyta blight disease pressure, PBA Seamer outperforms other varieties with minimal yield loss (2 to 15 per cent), compared with a 76 per cent yield loss in the industry benchmark chickpea variety PBA HatTrick.

PBA Seamer also offers moderate resistance to phytophthora root rot, which is equivalent to PBA HatTrick.”

As a result of its ascochyta resistance, Dr Ryan anticipates the new variety will require less fungicide, meaning reduced input costs for growers. Importantly, however, it is also expected to match or exceed the yield of existing varieties grown in Queensland and northern NSW.

“We have five years of yield data on PBA Seamer from trial sites north of Clermont to Dubbo, which gives us great confidence in the role of this new variety in northern farming systems.”

Dr Ryan’s optimistic outlook for the new variety is shared by Queensland grower Wade Bidstrup, who has hosted some of the trials on his family property on the western Darling Downs. “Chickpeas are rapidly becoming one of the most popular crops to grow and while prices are around $400 per tonne that trend is likely to continue and new varieties, like PBA Seamer, increase the crop’s appeal,” Mr Bidstrup says.

PBA Seamer agronomy

PBA Seamer is an earlier-flowering variety than PBA HatTrick, but takes the same amount of time to reach harvest maturity. It also has a larger seed, which is preferred by end users because this means greater milling yield. It is a semi-erect plant with better lodging resistance compared with other chickpea varieties. Queensland DAF senior extension agronomist Kerry McKenzie says PBA Seamer plants are shorter than other varieties and have a lower pod height, but stand better at harvest, which is critical in years when crops have a large biomass. It is generally well adapted to Queensland’s Central Highlands, the Darling Downs and the Maranoa region; and NSW’s Central and North West Slopes and Plains.

PBA Seamer has similar yields to PBA Pistol in Central Queensland and PBA HatTrick in southern Queensland and northern and central NSW,” Mr McKenzie says. “But it is not recommended for southern NSW chickpea-growing regions where trials showed yields were lower than currently recommended varieties.

Photo of PBA Seamer

Researchers have collected yield data over five years from PBA Seamer trial sites across the northern grains region from Dubbo, NSW, to north of Clermont, Queensland.

PHOTO: Toni Somes

“The combination of semi-erect habit, excellent lodging resistance and ascochyta blight resistance make PBA Seamer well suited to the higher-rainfall environments in southern Queensland and central and northern NSW.”

He says trials have shown PBA Seamer yield is optimised in these environments when the variety is planted on narrow rows of 25 to 50 centimetres, with a plant density of 25 to 30 plants per square metre.

Mr McKenzie says optimum results can be achieved where growers target the optimum planting window for their region, avoiding very early sowing to help minimise the risk of lodging. Later sowing also helps to reduce plant biomass, decreasing the risk of foliar diseases, he says.

“Sow high-quality seed at rates to achieve 25 to 30 plants per square metre, so typically, 60 to 75 kilograms per hectare depending on germination percentage and planting conditions. We also advise inoculating with Group N chickpea rhizobial inoculum.”

He says PBA Seamer is moderately intolerant of salt, and this intolerance is similar to PBA HatTrick and PBA Boundary, but there is no evidence the new variety is more sensitive to frost than other desi chickpea varieties.

Disease management and crop rotation

In Queensland and northern NSW chickpea-growing regions, PBA Seamer will generally only require a fungicide spray when disease is first detected, rather than the current practice of spraying after the first post-emergent rain event.

Ascochyta blight

However, NSW DPI senior plant pathologist Kevin Moore says growers need to be vigilant given forecasts for high ascochyta blight pressure this season.

“Yield loss in trials have demonstrated that PBA Seamer is significantly more resistant to ascochyta than PBA HatTrick and PBA Boundary,” Dr Moore says.

PBA Seamer’s resistant ascochyta rating means that disease development will normally be very slow, with minimal yield loss in most seasons.

Photo of sack of PBA Seamer chickpeas

Under high ascochyta blight disease pressure, the new PBA Seamer chickpea variety outperforms PBA HatTrick variety.

PHOTO: Toni Somes

“So in most seasons, there would be no cost benefit in applying fungicide before ascochyta is detected. However, in seasons with high disease pressure, a reactive foliar fungicide program and at least one pod protective spray may be warranted.

“However, as the ascochyta inoculum levels for the 2017 crop could be very high, I recommend growers consider applying fungicide to PBA Seamer before the first post-emergent rain event.”

Dr Moore also advises growers to monitor their crops 10 to 14 days after a rain event and to consult their agronomist if ascochyta is detected.

Phytophthora root rot (PRR)

PBA Seamer is rated as moderately resistant (MR) to phytophthora root rot, which is similar to PBA HatTrick resistance, but Dr Moore recommends a cautious approach to paddock selection where this disease has been detected. “Avoid paddocks that have a history of phytophthora root rot in chickpeas, irrespective of when chickpeas were last grown, as well as paddocks that are likely to have prolonged waterlogging after heavy rain.”

Botrytis grey mould (BGM) AND botrytis seedling disease (BSD)

Dr Moore says PBA Seamer is moderately susceptible (MS) to botrytis grey mould, and its superior lodging resistance compared with other varieties is an advantage under high crop-biomass conditions.

“Registered fungicide seed dressing is highly recommended for early control of seedling root rots, seed-transmitted ascochyta and botrytis seeding disease. Seed treatment has no effect on botrytis grey mould.

“Monitor for botrytis grey mould in spring as temperatures and humidity rise. Apply a fungicide containing either carbendazim and mancozeb once botrytis grey mould has been identified within a crop.”

Crop rotation

Dr Moore says it is vital growers continue to be careful about crop rotations, and allow a minimum of three years between chickpea crops to help reduce disease pressure and prolong the commercial life of the new variety.

“It’s important growers continue to pay close attention to paddock selection, crop sequence, variety choice, seed treatment, and have their strategic fungicide regime under control,” he says.

“It is particularly critical heading into what we anticipate could be a high-inoculum-level season, which has the potential to impact on productivity.”

More information:

Merrill Ryan, Queensland DAF,
07 4660 3610,

merrill.ryan@daf.qld.gov.au

Kevin Moore, NSW DPI,
0488 251 866, 02 6766 1133,

kevin.moore@dpi.nsw.gov.au

Useful resources

New era for northern chickpea production

PBA Seamer Desi Chickpea – fact sheet

End of GroundCoverTM #126 (northern edition)
Click to read the accompanying GroundCoverTMSupplement:

Statistics for the Australian Grains Industry


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