The International Grains Council backed concerns that Australian rains have fallen short of levels needed to resolve dryness, as it cut its forecast for the world rapeseed crop, downgrading European Union hopes too.
The intergovernmental group lowered by 1.3m tonnes to 68.5m tonnes its forecast for world rapeseed output in 2014-15.
While still a strong result, that would represent a fall of 2.5m tonnes from the record high set by the latest harvests.
Although Ukraine production was upgraded to 2.2m tonnes, after autumn-sown crop survived the winter "well", the estimate for China's harvest was trimmed by 300,000 tonnes to 14.7m tonnes, with yields expected to fall back from last year's record high.
The European Union harvest, the world's biggest, was downgraded by 300,000 tonnes to 21.1m tonnes, "with the crop in the largest producing member state, Germany, placed below last year, at 5.6m tonnes".
For Australia, the IGC slashed its production forecast for production of canola, the rapeseed variant, by 700,000 tonnes to 3.0m tonnes, citing the threat from dry weather in eastern Australia.
"Recent rainfall has provided some temporary relief, but was deemed insufficient to provide any substantial benefit," the council said.
"With planting due to begin around April, weather conditions over the next month will be crucial for canola prospects, as insufficient soil moisture could cause some farmers to switch to planting other crops such as wheat or barley, which are more tolerant to dry conditions."
Indeed, the IGC, while in line with Australia's Abares bureau on canola prospects, was more upbeat on hopes for wheat, pegging the 2014-15 harvest at 25.5m tonnes.
Abares earlier this month forecast the Australian wheat crop at 24.8m tonnes.
The IGC said that, despite its forecast for a 200,000-tonne decline in German rapeseed production this year, it was upbeat on prospects for other major EU growing countries.
"The region's output is seen rising by 1% year on year amid a favourable yield outlook in many countries, including France and the UK, where productivity is expected to recover significantly despite a very wet winter."
Separately on Friday, producers' group Copa-Cogeca pegged the EU rapeseed harvest at 21.0m tonnes, just short of the IGC estimate, and last year's 21.3m-tonne crop.
The group highlighted a "positive situation" for oilseed and protein crops in many European countries "due to the mild winter this year and good winter sowings".
Indeed, although "it is still very early on in the growing season, crops look in very good condition", Copa-Cogeca said, adding that it "is expecting good production for the 2014 harvest.
In rapeseed, "EU growers are expected to provide a good harvest and sufficient meal for EU livestock producers which may alleviate the impact of possible cuts in production in the southern and northern hemisphere".