Argentinian union workers blocked access to several ports around Rosario city on 7 July, impacting export activity in the key export hub of the Up River complex, AgriCensus reported.
Rosario is located on the west bank of the Paraná River and UOCRA union workers blocked access to the ports of San Martin, San Lorenzo and Timbues, the report said.
The actions started on Tuesday morning, when workers stopped trucks carrying grains and other commodities into the installations of the exporter Molinos Agro, located north of Rosario in the Up River hub city of San Lorenzo.
The company was only able to process volumes held in stock, while all daily arrivals were cancelled, according to local press reports.
Blocking other ports would also have impacted export activity.
"Not letting trucks in with primary products [to be processed and exported] makes the ports inoperable," an industry source told AgriCensus.
Workers were demanding a bonus for subcontractors that provided a yearly maintenance service to export plants.
Argentina is a key exporter of agricultural commodities globally, including corn, wheat, soybean oil and meal and animal feed.