Unusually hard early-season rains made this season's wheat vulnerable to water-born fungi that attacks plants' protein content. Floods posed other logistical problems as harvesting machines sank in the mud and access roads were washed out.

“Yields in the main wheat region of the country did not reach what was estimated at the beginning of the season due to crop health problems, excess water in August, several heat shocks in November and bouts of hail and strong winds during the harvest,” the ministry said in its monthly report.

The season started at a disadvantage when many farmers shifted to soy and other crops to skirt the export curbs that the government places on wheat. Growers planted 3.5 million hectares with wheat, down 25% from the 2011/12 crop year.

The Buenos Aires Grains Exchange issued its weekly crop report saying it expects Argentina's 2012/13 wheat harvest to come in at 9.8 million tons, a good 30% under the 2011/12 crop.

“The loss is principally due to the inter-annual reduction in planting area,” the exchange said. “Yields were also affected by excessive rains.”

The ministry kept its soybean area estimate unchanged at 19.35 million hectares and corn estimate unchanged at 4.6 million hectares.

Argentina, the world's No. 3 exporter of soybeans and corn after the United States and Brazil, is expected to produce record harvests of both crops this season.

The government sees the soy harvest at 55 million tons or more and it expects a corn haul of 28 million to 30 million tons. But the country needs rain by the end of the month to support corn flowering, maximize yields and realize that forecast, farmers and agronomists say.

According to the exchange, 93.4% of Argentina's 2012/13 commercial use corn is in the ground, marking an advance of almost 5 percentage points during the week.

Argentine farmers have planted more than 96% of their 2012/13 soybeans, having advanced 5.3 percentage points over the week the exchange said.

MercoPress