Says unilateral moves by Poland, Hungry will not be tolerated.

Multiple factors taking a toll on farmer profitability.

Economic sanctions remain sticking point for May 18 deadline.

Cheap prices had sparked farmer protests.

When geopolitical tensions escalate, free trade is often a casualty.

State grains buyer GASC makes tender for two May deliveries.

Grain production, infrastructure to be aided by agreement worth 40 million euros.

Company operates Don river terminal on Sea of Azov.

Farmers angry over falling prices due to influx of grain.

Move comes day after Cargill says it will stop elevating grain July 1.