Abstract
Early infection of sugar beet plants with BYV reduced fresh weight and length of plant and root by 25,33,17,20 and 33% respectively ,in addition to the reduction of sugar percentage and root content by 18.5 and 51% respectively .Also early infection with BCTV reduced fresh weight of aerial and root content by 28.5 , 40 as well as shoot and root length respectively .reduction of the percentage of root sugar and its content in root by 17.4 and 50.2% was recorded. The screening study for the susceptibility of sugar beet plant to BYV and BCTV ,demonstrated that triple variety was the least susceptible to BYV whereas semarive was the most susceptible. Also Triple showed resistance against BCTV among other varieties. the varieties Viro, Tenor and S.H.1613 were susceptible .
