Cold, nasty weather and a cooling economy put a decided chill on March retail sales in the US, which came in sharply below already-tempered plans for most retailers the Wall Street Journal reported today. Shoppers particularly shunned department stores, but even some of the country's most popular chains, such as Kohl's Corp. and Talbots Inc, also lost steam last month. Sales have been so soft that both Wal-Mart Stores Inc and Sears, Roebuck & Co, warned that first quarter earnings may fall short of Wall Street estimates. Their projections dragged down retail stocks, though some rebounded by the end of the day.