The heavy rains in Canada, which have revived canola and spring wheat prices, are forcing some growers to resort to take to the air to finish seedings, while threatening others with a wipeout.

Growers in Saskatchewan, which produces nearly half of Canada's canola and wheat crops, have on average nearly one-third of their 2010 crops left to seed.

However, in eastern areas, where "there has been very little farming activity for a few weeks", some farmers have only 5% of their crop in the ground, and with the window for plantings nearly closed.

"Some producers are indicating that, by the time the land can support equipment, it will be too late to seed anything," a report from Saskatchewan government farm officials said.

'Large tyre ruts'

The poor conditions, caused by rainfall of up to 11 inches over the last two months, are prompting growers to turn to fast-maturing crop varieties, or leaving land fallow.

"Working in the wet fields is difficult. Sprayers are getting stock and leaving large tyre ruts," the briefing said, reporting that growers were increasingly resorting to spraying from aircraft to avoid damaging fields.

In neighbouring Manitoba, officials reported that "aerial seeding has been used in some areas", a technique usually associated with extreme conditions, and which tends to produce lower yields.

Meanwhile, crops already in the ground are suffering from the wet conditions, with an "increasing number of fields showing symptoms of water stress" in Manitoba, and 10-60% of crops in parts of the east of the province exhibiting yellowing symptoms.

Estimate cuts

The reports come as analysts are cutting by more than 500,000 acres their forecasts for Canada's canola plantings, which had been expected to rise by 4% to 6.8m hectares, according to official data.

Some 1m acres of spring wheat sowings have yet to be sown, according to US broker Benson Quinn Commodities.

The revisions have fostered a rise of 6% in Canadian canola prices this month, which closed on Thursday at Can$394.00 a month for July delivery, a five-month high for the spot contract.

They have also fostered an outperformance by wheat prices in Minneapolis, the home of dealing in US spring wheat, over those in Chicago, which trades the soft red winter variety.