Bad weather derailed Martha Stewart’s plans to ride in a giant pumpkin on a lake in Windsor, Nova Scotia. But residents who braved a downpour to watch competitors in the annual Pumpkin Regatta already were calling on Stewart to try again next year. Her flight was grounded Sunday morning at a Maine airport as heavy rains fell across the East Coast. Stewart had been expected to settle into a giant, hollowed-out pumpkin and paddle her way across Lake Pesaquid, alongside 40 other competitors. Stewart’s film crew arrived in Nova Scotia the day before the race to decorate the 660-pound pumpkin. It was painted in stripes of pastel blue, orange, yellow and green. Canadian officials initially had refused Stewart, 64, entry into the country because of her conviction for lying about a stock sale. That issue had been cleared up.