Growers in the soy region of Alto Jacui and larger land owners in the state, many of whom have been planting GM soy for three years, drove over 1,000 tractors into the main plaza of the town Nao-Me-Toque, an important soy center for the northeast region of the state, to demand an end to the ban.

Meanwhile, about 2,500 small farmers that grow conventional, or non-GM, soy marched in the state capital of Porto Alegre last week demanding the segregation of illegal transgenic crops from their conventional soy crops along the production chain of shipping, storage and processing.

"We want the right to sell our conventional and organic crop," said Aureo Scherer, coordinator of the Small Farmers Movement (MPA).

The movement represents farmers with 50 hectares (124 acres) or less who fear that they will get lower prices for their soy if it is considered to be transgenic. Their march was directed at the state government, which has spoken out against the segregation of GM and conventional crops.

"If we separate the crops, we would cause chaos in trading and there would be a certain disqualification of the value of our crop," Odacyr Klein, state agriculture secretary, told Reuters.

The State Granary Warehouse Company (Cesa) would not distinguish between GM or non-GM soy coming into storage, according to Klein.

"There won't be separation (of grains) in Cesa," said Klein. Cesa has a static storage capacity of 800,000 tonnes and can move about 2.4 million tonnes or 30 percent of the state's soy harvest of 8.5 million tonnes.

ANTI-GM PRESSURE

Small farmers account for some 50 percent to 70 percent of Rio Grande do Sul's output, according to the state and federal governments. And the segregation of the soy crop is favored by the Workers' Party (PT), the party of President Luiz Inacio Lula da Silva.

Federal PT deputies from the state filed an official request to the state and federal government to guarantee the separate commercialization of the GM and conventional crops with special measures for the storage, transport and examination of seeds.

On Wednesday, the MPA protested in front of the Porto Alegre offices of Monsanto Co. (MON.N), accusing the company and the state Agriculture Federation (Farsul) of facilitating a black market in illegal GM seeds in the state and demanding remuneration from the company for any losses.

"We know who planted and it would be possible to identify who is responsible," said the MPA's Scherer.

Monsanto said in a statement this type of protest could be attributed to Brazil's lack of judicial clarity and definition over the cultivation of genetically modified plants.

Monsanto is one of Brazil's largest sellers of conventional seeds and agrochemicals.

"Monsanto always conducted its activities in a transparent way and in accordance with Brazilian law," the statement said.