China, the biggest wheat producing country, has underpinned hopes for the country's wheat harvest just as Russia, the growing export force, is cutting grain output forecasts.

The Chinese agriculture ministry said it expected winter wheat production this year to come in slightly ahead of last year's. While failing to give figures, the estimate bodes well for the overall wheat harvest, after cold weather setback the spring crop.

Winter wheat accounts for 90% of China's total wheat crop, which the USDA has forecast declining 2.5 million tonnes to 112.0 million tonnes this year.

Meanwhile, Russia's farm minister, Yelena Skrynnik, has cut the estimates of the grain harvest to 88-90 million tonnes, from 97 million tonnes.

The reduction reflected worsening estimates for the damage caused by a cold winter, which destroyed 30-40% of crops in some areas, and the impact of a late spring on sowings.

However, industry figures have voiced prospects of a significantly larger crop, with the Russian Grain Union standing by a forecast of production potentially topping 100 million tonnes, if weather for the rest of the season proves benign.

Some observers have raised doubts about levels of winterkill, which have, in Russia as well as in neighbouring Ukraine, proved contentious.

"There is scepticism within the trade that winterkill figures and production declines are being inflated in order to support domestic prices and increase grower returns," analysts at Rabobank said.