On Sunday, patrons shopped at the South End Open Market for the first time since a bitter personal and legal feud with the market’s former landlord last year forced it to leave its longtime Harrison Avenue home and move down the street. Meanwhile, the former landlord, Mario Nicosia, debuted his rival market at the original site, dubbed the SoWa Open Market. Near right, a jewelry vendor at the South End Open Market; far right, a produce stall at the SoWa Open Market.