The Grains Research and Development Corporation has released the results of 150 canola trial results from across the country with the major finding that genetically modified canola did not significantly outyield Clearfield.
Proponents of GM canola said this was always to be expected, and that GM canola was not being grown for its yield advantage, but rather for its rotational benefits, while critics said it was a case of Roundup Ready technology not living up to the hype.
The findings came from the National Variety Trials at the 15 GM canola trial sites.
There were five GM trial sites each in three states, NSW, Victoria and Western Australia, across a range of climatic zones, and GM glyphosate tolerant varieties were tested against both triazine tolerant (TT) and imidazolinone tolerant, or Clearfield lines.
Of the 15 trials, three failed: one in Temora, NSW, due to the drought; one in Lake Bolac, Victoria, due to blackleg; and one in Frankland, WA, due to contractor error.
The trial data backs up long-term statistics that show TT canola is lower yielding that other lines, but when comparing Clearfield and Roundup Ready lines, things became more blurred.
The GRDC found that in three trials the Clearfield varieties were the highest yielding, while the RR lines were clearly better in two trials.
In five trials, there was little difference between the Clearfield and RR lines; in one trial there was no statistical difference between all three lines; while one trial was considered too varied to publish.
Over all the trial sites combined, there was a slight, not statistically significant, yield advantage for RR at 2.08t/ha over Clearfield at 1.97t/ha, and TT at 1.87t/ha.
GRDC’s manager gene discovery Dr Juan Juttner said this year’s data was not a conclusive answer as to the yield ranking of canola varieties, although it was better than 2008 when drought meant there were virtually no trial results.
"We have 11 trial sites successfully harvested and analysed, but it’s still a limited dataset and difficult to draw any firm conclusions on one variety’s performance compared to another," he said.
"There is an inherent level of variability in the results of variety trials across locations and years, so you need multiple trials across a number of years to confidently predict variety performance."
He said more GM canola trials will be planted in 2010, including a greater number in Western Australia following the State Government’s decision to lift its moratorium.
Gene Ethics director Bob Phelps said little could be drawn from such a small-scale trial.
"The trials suffer from being small scale and widely scattered, with very mixed and inconclusive results. No general conclusions can be drawn from 15 sites, especially when 20pc failed," he said.
He also called for conventional canola lines to be included in the GM trial
"GRDC intentionally makes no comparison of herbicide tolerant types with the best conventional varieties," he said.
"The most accurate comparisons of different canola crops would be gained from well designed surveys of commercial plantings.
"Such surveys would include the conventional varieties and would show RR GM is a mediocre performer."
Monsanto officials said they were pleased with the results.
James Neilsen, Monsanto canola systems specialist, said the NVT results showed RR had good yields, combining with its agronomic flexibility.
"These results clearly show that the Roundup Ready canola system offers growers higher yields in addition to superior weed control," he said.
He said the NVT results were a well-regarded information tool for farmers making planting decisions and that it was good to see RR measure up well against the other varieties.
Copyright ©2010 Fairfax Media
