Dock workers in Argentina’s Rosario grains hub demanding higher salaries will begin an indefinite strike from midnight (0300 GMT) on Wednesday, a senior union official told Reuters on Tuesday.

Strikes and labour disputes are common in Argentina. With inflation estimated at more than 30 percent, one of the world’s highest rates, Argentine unions have hunkered down for a tough round of wage talks.

“We start this strike at midnight and by 6 a.m. (0900 GMT) all terminals will be affected,” said Humberto Reynoso, Secretary General of the Union of Grain Recipients of Argentina (Urgara) in Rosario.

The work stoppage would come at the height of Argentina’s harvest of soybeans and corn. The South American country is the world’s top exporter of soyoil and soymeal, as well as its No. 3 supplier of corn and soybeans.

Port labourers went on strike briefly in June, disrupting the loading of more than 100 vessels.