Frost management high on western cropping agenda

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Grain growers in some frost-prone areas of Western Australia celebrated the 2013 season without a damaging cold snap. But long-term trends indicate frosts are becoming more frequent and growers in the region need to actively manage for potential frosts each season

Photo of man with wheat and hay bales

Western Australian grower Wade Hinkley says his ideal frost-prevention toolkit would include a practical strategy to help make ‘hay or harvest’ decisions for frosted paddocks, rather than relying on visual assessment to gauge if crops are still growing.

PHOTO: Evan Collis

With six of the past 10 years delivering frosts significant enough to wipe out a large proportion of Western Australian crops it is no surprise that most growers in the region rank frost management at the top of their research, development and extension wish list.

As president of the local Facey Group, Tincurrin, WA, grower Wade Hinkley keeps a close eye on research – especially frost research.

Wade says his ideal frost-prevention toolkit would include a practical strategy to help make ‘hay or harvest’ decisions for frosted paddocks, rather than relying on visual assessment to gauge if crops are still growing.

“We had a really bad frost in September 2012 and lost 50 per cent yield in some paddocks,” he says.

“We baled the worst of the frosted wheat, which tripled our returns compared to the areas we left to harvest.”

Although hay offers an alternative market and helps drought-proof their livestock the family also relies on a ‘prevention’ strategy based on variety selection and management.

They use the Department of Agriculture and Food, WA, online tool Flower Power calculator to identify varietal seeding dates to target optimal flowering.

Grazing is sometimes used to manipulate flowering until after the frost period. Other frost-management strategies include:

  • thermal imaging, which has identified a 3ºC to 4ºC difference in minimum temperatures between paddocks, guiding where frost-sensitive varieties are planted;
  • planting frost-prone paddocks last to help avoid the high-risk frost period;
  • using paddock records to monitor frost history; and
  • planting according to frost-prone areas, such as concentrating pasture crops and hay varieties on sandy zones and around creeks.

Farming frustration


Peter Roberts identifies frost as his most frustrating farming challenge, but the WA grain grower says he is optimistic research is edging closer to delivering wheat varieties that are more resistant to these extreme cold snaps.

Rather than sow crops later and take a hit on yield potential, Peter today sows a range of crops and varieties with differing flowering times.

On low-lying parts of the farm he sows barley and oats. Where wheat is grown on frost-susceptible areas, the later-flowering variety YitpiPBR logo is preferred. He has tested FangPBR logo wheat in small plots, but found its growth period too long for his environment.

“As growers, we often sacrifice yield to mitigate the damage that frost could potentially do to our crops by sowing later and with less profitable cultivars, such as oats, on frost-prone sites,” he says.


‘HAY OR HARVEST’ TOOL

New ‘proof-of-concept’ research planned for 2014 will investigate the possibility of using remote sensing technology to detect frost damage in wheat and the likelihood of these damaged crops going on to yield sufficient grain.

If a tool, based on the potential method, could be developed it would help growers decide how much of a frosted crop to cut for hay or grain.

The goal is to combine biomass and yield estimates via satellite or aerial imagery with a measure of frost damage collected via grower records and yield mapping data.

Using this information researchers will then attempt to calculate a frost-induced yield map.

Growers with yield mapping capabilities will be approached to identify at least five paddocks in which wheat has previously suffered frost damage.

A further five non-frosted paddocks close to the frost-prone paddocks will be selected as controls. The 10 paddocks will then be mapped using satellite imagery and yield maps. From these, the relative yield impact of frost-induced stress will be calculated.

Satellite images with 28 metre by 28 metre spatial resolution will be obtained for the time points immediately before and in the weeks following the defined frost events.

A range of analytical procedures will then be assessed for their capacity to predict the yield of frosted paddocks.

 

Instead, Peter has sought to maximise yield from the same level of inputs by sowing early with effective weed control.

Rather than wait for the seasonal break, Peter adopts a sow-by-the-calendar approach, planting dry and using technologies that allow him to chase weeds. Two examples of available technology are Clearfield® wheat and barley and Roundup Ready® canola. In 2011, he bulked up new Intervix®-tolerant varieties of wheat and barley.

Photo of kneeling, smiling man

Western Panel chairman and grower Peter Roberts
rates frost as his most frustrating farming challenge.

PHOTO: Nicole Baxter

 

“The biggest driver of higher yields is time of sowing,” he says. “Crops have to be in the ground early.”

More immediately, he says, a “kicker” for improving farm profit in high-rainfall areas is integrating crop and livestock systems through grazing canola and grazing cereals, which has been validated through the GRDC’s investment in Grain & Graze 2.

“It can take guts to open the gate on a bulky canola or wheat crop,” he says. “But we can do this with our current best adapted varieties. All that’s needed is the opportunity to sow early, have good weed control and then graze them hard. This allows more crop to be grown other than by reducing stock numbers.

“Studies so far have shown there is very little decrease in yield, usually an increase in protein and the extra benefit of being able to push back the flowering window, which also helps in managing frost.”


More information:

Dr Juan Juttner, senior manager discovery, GRDC,
02 6166 4558,

juan.juttner@grdc.com.au

 

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Late frosts cause southern concern

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Identifying frost in wheat

GRDC Project Code UWA00160, DAW00234, DAW00162

Region West, National, North, South