to determine the role of fusarium species associated with sugar beet root and crown rot, diseased samples were collected from different fields of sugar beet in iran including khorasan, khuzestan west azarbayejan, qazvin, tehran, kermanshah ,kerman,lorestan ,hamedan,charmahal va bachtiary provinces during growing seasons 1999-2002. in total, 94 isolates of fusarium were obtained. based on morp...