US officials countered gloom on Argentina's row crops by saying it was too early to give up on corn, despite considerable rain delays to plantings, adding that there was "plenty of time" for soybean sowings.

The US Department of Agriculture's Buenos Aires office cut its estimate for Argentina's wheat crop, which is in the early stage of harvest, because of the "very rainy and humid" conditions which have prompted "serious flooding" in some areas.

"The humid environment is encouraging the occurrence of diseases, which producers are treating the best way possible given the complicated situation of roads and soil conditions," the bureau said, pegging the harvest at 10.8m tonnes, below the USDA's official estimate of 11.5m tonnes.

The forecast for 2012-13 wheat shipments from the southern hemisphere's second-ranked exporter to a 17-year low of 4.8m tonnes –a slump of 62% year on year.

Not all bad

However, on corn, the office raised its harvest forecast, to 28m tonnes, putting it in line with the USDA figure, flagging a silver lining to the downpours hampering sowings.

"Although planting is delayed on account of the very wet spring, the amount of water in the soil is likely to guarantee a very good crop."

The comments contrast with those on Thursday from the Buenos Aires grains exchange which - estimating that farmers had completed 40% of seedings compared with 57% usually by now – cautioned that flooding had leached away fertilizers and caused soil damage which was threating "normal emergence" of some crops.

Indeed, many analysts foresee a crop far lower than the USDA bureau expects.

"Informed sources advise us that Argentine corn crop closer to 25m tonnes," Richard Feltes at broker RJ O'Brien said, adding that such an outcome would "further tighten an already snug global corn supply and demand balance".

'Plenty of time'

The USDA bureau also flagged that the Argentine soybean area could rise, depending on long flooding lasts, with the oilseed having a later sowing window, and requiring less fertilizer to grow.

There is plenty of time for producers to start planting [soybeans]," the office said, flagging that while "corn returns are higher than soybeans', the investment needed is roughly 70% more".

Although the bureau did cut its estimate for Argentina soybean exports, that was down to an expansion in the domestic crush rather than reduced hopes for output, and balanced by raised expectations for soyoil and soymeal shipments.

"Since there have been policy changes from the government with the goal to provide incentive to the crushing industry and promote crushing at full capacity, it is likely that more soybeans will be crushed in the coming year."