May 21 (Reuters) - Canada’s main stock index rose at open on Friday, drawing support from energy stocks tracking a rise in crude oil prices as economic reopening raised summer demand hopes, while a rise in retail sales also lifted sentiment. * At 09:31 a.m. ET (13:31 GMT), the Toronto Stock Exchange’s S&P/TSX composite index was up 61.08 points, or 0.31%, at 19,604.03. Reporting by Shivani Kumaresan in Bengaluru; Editing by Vinay Dwivedi Our Standards: The Thomson Reuters Trust Principles.