Abstract
During January-February 2010, a black root rot (BRR) disease of carrot (Daucus carota L.) was observed in vegetable markets of Riyadh, Saudi Arabia. The recovery of Thielaviopsis basicola from local carrot fields indicated its appearance in propagules ranged between 8.32-10.15 (total count/g soil). This report describes the first evidence of black root rot disease of carrot caused by T. basicola in vegetable markets of Riyadh (Saudi Arabia).