Workers in Argentina’s main grains port of Rosario will begin an indefinite strike on Friday over labor conditions, according to a statement by the country’s powerful CGT labor organization on Wednesday.

Argentina is the world’s No. 1 exporter of soymeal livestock feed and third-biggest supplier of corn and raw soybeans.

The CGT statement did not provide details of the labor conflict but said a decision would be taken on Monday whether to continue the work stoppage, which comes at peak harvest time for soy and corn.

A source close to the situation said the dispute stems from a request by the General San Martin Port Service Cooperative, which loads and unloads cargo ships, for higher tariffs to be paid by grains exporters.

Strikes and other labor disputes are common in Argentina, where inflation of 30 percent often leads to high wage increase demands.