SAO PAULO, July 3 (Reuters) - A national protest by Brazilian truck drivers appeared to be winding down on Wednesday and the union leading it said it was scheduled to end at 6 a.m. (10 a.m. GMT) on Thursday, after several state governments secured injunctions to stop drivers from blocking public highways.
Local media showed trucks that had been abandoned in Mato Grosso, Brazil's leading soy producing state, while drivers demonstrated on the Anchieta highway that links Sao Paulo to Brazil's main Santos port. Private highway operator Ecovias said protesters had caused a 4 kilometer (2.9 mile) traffic jam.
President Dilma Rousseff, whose popularity plunged in recent weeks during Brazil's largest nationwide demonstrations in 20 years, rebuked the truckers and pledged in a televised address to the nation to keep roads in running.
The 72-hour truck strike, organized by Rio de Janeiro-based truckers union MUBC, was unrelated to demonstrations in which Brazilians have voiced grievances over public services and transportation, corruption and healthcare.
Among MUBC's demands is a subsidy for diesel fuel and exemptions on highway toll payments for drivers. The national union's spokeswoman did not respond to repeated requests to confirm that the protests would end on Thursday.
Dockworkers staged a separate protest on Wednesday at the entrance of Santos port, provoking six kilometers of congestion, but they did not block the entrance, a port spokesman said.
Calls for a general strike have so far gone unheeded, although dock workers at Brazil's main port of Santos have called for a walkout on July 10 and 11.
Analysts have said the three days of roadblocks are unlikely to affect exports of Brazil's record soy, corn and sugar crops as exporting companies keep enough supplies in private storage facilities near the ports to keep loading ships.
Some two-thirds of grains shipments in Brazil arrive to the port via truck.
The union staged a week-long strike a year ago, disrupting the flow of goods in Brazil's heavily populated southeast region and raising concerns over food inflation.