Argentine soy and corn prices posted sharp losses on the week at the Rosario Grain Exchange Thursday (October 2), in line with losses at the CBOT.

The sharp sell-off on Wall Street spilled over to commodities this week on concerns about a worldwide economic slowdown and decreased demand for grains.

"Grain prices fell under the influence of Chicago and the lack of buying interest – the start of the farm strike tomorrow will make deliveries difficult and buyers were hesitant to buy big lots," the Rosario Grain Exchange said.

On Tuesday, the leaders of Argentina's four top farm groups announced a new six-day strike starting Friday. At the end of the strike, they will meet to discuss their next moves.

The farmers vowed not to block roads, but will stop buying and selling grains for export and live cattle, Rural Society President Hugo Biolcoti said.

However, the sale of goods from drought-stricken areas won't be blocked, Biolcoti said.

Farmers are protesting a series of government interventions in the sector, including high export taxes and limits on beef, corn and wheat exports.