Wheat prices clawed back into positive territory as fears rose that Russia's output may fall below drought-hit levels of 2010, curbing the drag from lower corn and soybean markets, which were depressed by Midwest rains.
Wheat for September delivery closed up 0.3% Chicago, rebounding from losses of 1.7% at the intraday low.
Wheat in Minneapolis and Kansas also recovered from of their early low.
The revivals followed confirmation at the weekend of a 290,000-tonne wheat order from Saudi Arabia, a further evidence of demand even at elevated price levels.
And on Monday, SovEcon cut its estimate for the Russian harvest to 72m-75m tonnes.
'Consider threat seriously'
The downgrade, trailed to Agrimoney.com by SovEcon managing director Andrey Sizov last week, included a cut to 40.3m-43m tonnes in the forecast for Russia's wheat harvest, from a previous estimate of 46.5m tonnes.
That could see it the crop end up below the 2010 level of 41.5m tonnes, a harvest which prompted Russia to ban grain exports, underpinning higher prices.
Crop prices as of close on Monday
Chicago wheat, (September): $8.93 ¼ per bushel, +0.3%
Kansas wheat (September): $8.96 per bushel, unchanged
London wheat, (November): £191.50 per tonne, -0.3%
Chicago corn (December): $8.05 per bushel, -0.6%
Paris wheat, (November): E258.50 per tonne, -1.0%
Chicago soybeans, (November contract): $15.84 ¼ per bushel, -2.8%
The debate from the respected Moscow-based consultancy follows conflicting talk last week on the size of the Russian harvest, which a government source told Reuters could top 50m tonnes, and efforts by officials to downplay the risk of fresh export curbs.
"You have to consider the threat of some kind of action [by Russia] seriously," a UK grain trader told Agrimoney.com, flagging to risk to Russian livestock producers from a squeeze on grain supplies.
"When you are talking about a harvest that low, you would not expect the Russian government to stand idly by and watch grains leave the country, and undo the efforts it has made to build up the livestock industry."
In the US, broker Doane said: "The continued deterioration of crop estimates for Russia is reviving warnings that country may have no choice but to suspend new grain sales like it did in 2010, even though last week Prime Minister Medvedev decidedly ruled that out."
'Story for wheat only beginning'
The comments come amid continued concerns too for wheat crops elsewhere in the former Soviet Union, and in Argentina, Australia and parts of Europe, where dryness has also been a threat.
In the US, the drought, if it continues into autumn, could hamper sowings of winter wheat for 2013 too.
Matthew Pierce, trader at GrainAnalyst.com, said: "Heading into the planting season for soft red winter wheat and hard red winter wheat, the story for wheat is only beginning while the story for corn feels played.
"Problems in Australia, Argentina, Russia and Kazakhstan - the issues with wheat are expanding by the day."
Rains – at last
However, corn and, in particular, soybean prices fell after rains refreshed Midwest crops over the weekend to a far greater degree than forecasts had anticipated.
"Waves of strong thunderstorms on the weekend produced more than one inch of rainfall on 65% of corn and soybean farms," Gail Martell at Martell Crop Projections said.
"It was the best weekly rainfall since late May in the grain belt."
US Commodities said: "The weekend's rains should help soybean prospects but is likely too late to give much help to corn."