WESTERN Australian research presented at last week’s GRDC Grains Research Update in Perth has confirmed barley is better than wheat when getting the best from early-sown crops in frost-prone landscapes, but oats is also a viable option.
The Department of Primary Industries and Regional Development (DPIRD) trials at medium production zones, Kulin and Quairading, and high production zones, Wickepin and Dale, examined the performance of longer season varieties of wheat, barley and oats impacted by frost.
DPIRD senior research officer Ben Biddulph said barley was more able to maintain grain yield and gross income than wheat in all sowing windows from mid-April to mid-May, under moderate and severe frost.
“Under moderate frost environments, longer-season barley varieties sown in early to late May produced the highest grain yield and gross income of all crop types evaluated,” Dr Biddulph said.
“Under severe frost, long-season oats were able to maintain higher grain yield and gross income compared to barley.
“However, the lower historical price and lower grain yield potential in low rainfall environments of oats relative to barley, reduces their usefulness as a frost management tool.”
Dr Biddulph said choosing a crop depended on the terrain, position in the landscape, growing season rainfall and growing season length.
“In Kulin, which is a low rainfall area with frost prone areas, it would be best to grow Bannister oats and barley in mid April.” he said.
“The difference between wheat and oats in this area was between $700 – $900 a hectare, with wheat being the losing grain.
“Early June sowing showed a benefit of barley over oats with wheat still lowest, but more frost resistant at this time with Scepter being the best performer for wheat.”
In Quairading early-sown oats were the best return but as it goes into early May barley becomes more competitive with wheat still lacking, with the best income coming from sowing barley late, oats early or wheat in early June.
In the higher production environments and seasons at Wickepin and Dale, longer season strong and mild photoperiod responsive wheats such as Forrest, sown in early May, and the mid-long varieties such as Cutlass, sown in late May, were able to maintain grain yield, quality and gross income competitive with barley in mild frost environments.
In early June, mid-season wheat varieties such as Scepter generally produced the highest gross margin of the wheats available.
“Optimising crop and variety choice at sowing time to minimise frost exposure is still the most important way farmers can minimise frost damage,” Dr Biddulph said.
He said growers should be mindful of the opportunity cost of sowing mid-season varieties of all crop types in late April and early May, as they did not optimise grain yield and quality compared to mid and late May sown crops.
In a high rainfall areas, with 350 millimetres plus of annual rainfall, in mid April the best returns would come from seeding Bannister oats, and long seasons wheats.
Dr Biddulph said if seeding late April, the barley should out perform the oats but the longer-season wheats should still come out in front.
“Growers should consider planting longer season oats, barley and then longer maturity wheat varieties when early opportunity arises, rather than the commonly used mid-season varieties,” he said.
“This will ensure adequate biomass is accumulated both above and below ground, and can be converted into grain yield, while managing frost risk.
“This may also reduce the potential opportunity cost associated with lower yield and greater frost damage in seasons when frost occurs and affects grain yield and quality.
“In high and medium production environments, sowing oats and barley in late-April to mid-May, and then mid-long wheats in late May, is still the management practice which achieves the highest gross income in frost-prone environments.”
