The field experiments were conducted at two locations, Tag EI-Ezz
experimental station and Belkas region in Dakajhlia Govemorate during agricultural
seasons (1997/98 and 1998199) in clay loam soil to study the effect of some factors
(sowing dates 15th, 30th October and 151h November) and some sugar beet varieties
(Top, Gloria, Oscar and Pamela) to know the effect of these factors on yield and
some diseases. The varieties which were planted at 151h of October gave the least
percentage of diseases and the highest yield, followed by the 30th of October, while
those of 15111 of November gave the highest percentage of infection and the lowest
yield. The main results of this study revealed that sugar beet sown at 15th October
gave the highest yield of root as well as sugar yield. Delaying of sowing date to 15th
November reduced sucrose contents.
The cultivar Top was the best cultivar when gave the lowest percentages of
Damping-off, Cercospora leaf spot and Root-rot diseases and the highest yield
followed by Gloria, Oscar while Pamela gave the highest percentage of infections and
the lowest yield. The interaction between sowing dates and varieties gave different
effect of infection percentage and yield in two agricultural seasons.