Argentine farmers are to cut corn plantings by 19% this season, the Buenos Aires Grains Exchange has said, in the latest dent to the country's reputation as an agricultural powerhouse.

Farmer have started corn sowings with the intention of plant 2.0m hectares, down from 2.46m hectares last year, the exchange said.

The exchange appeared to suggest that the decline reflected in part farmers' escalating row with the government over measures including export taxes, noting that "the lack of clear perspectives for the market" and "farmers uncertainty" were leaving growers reluctant to commit.

Farmers, who have longstanding complaints over levels of export duties, particularly on soybeans, are on Friday due to start a one-week strike.

Relations between President Cristina Fernandez and growers were further damaged this week by her rejection of part of a farm law that would have exempted some farmers hurt by Argentina's drought from export duties.

Yield challenge

The exchange rated fears over dry weather, which was beginning to take its toll on wheat seedlings in western areas, as another reason that farmers were holding back on corn.

The drought conditions which prevented sowings, and hurt yields, led to a 40% slump to 13.0m tonnes in Argentine corn production in 2008-09.

The US has forecast output reviving to 15.0m tonnes in 2009-10, a figure which would require yields coming in near the 8 tonnes per hectare achieved three years ago.

The exchange has pegged Argentina's wheat sowings this year down 40% at 2.75m hectares, reflecting continuing dry conditions in many areas.