Two field experiments were carried out at EI-Serw region in Northern
Faraskour district Damitla Governorate to investigate effect of planting dates, nitrogen
levels and biofertilization treatments as well as their interactions on yield and quality
of sugar beet (Beta vulgaris, L.) variety Top. The main results could LJe summarized as follows: Some yield components character i.e. root length, root diameter, root fresh
weight, foliage fresh weight, and root /top ratio (in the second season) were exerted a
significant effect as a results from planting dates treatments. The treatment from
planting dates which gave the high values was planting on 15th of October of all yield
components except root diameter (in the second season only) and rootltop ratio in
both seasons. In the first season root quality characters (TSS, Sucrose and juice purity %)
were insignificantly affected due to the planting dates treatments. The highest values
of yield quality characters were planting beet on 15th of October over both seasons). Planting dates treatments had significant effect on root yield, top yield, sugar
yield and harvest index. Planting dates on 15th of October gave the highest values of
yield characters except harvest index.          -    Raising nitrogen fertilizer levels from 0 to 20, 40, 60 and 80 kg N/fad showed a
significant increase on all yield components and yield in both seasons except
root/top ratio resulted from fertilizing beet with 40 kg Nlfad. Vice versa the
highest values of TSS, sucrose and purity % were obtained from control
treatments (without N-fertilizing) in both seasons.          -    Biofertilization treatments had significant effect on all yield components and yield
and the best treatment with biofertilizer was rhizobactein treatment except root
/top ratio were obtained from uninoculation seeds. - TSS %, sucrose % and juice purity %, the highest values of these characters
were obtained with uninoculation treatment (control). The interaction between
planting dates and nitrogen levels had significant effect on all yield components
and yield characters except root ftop ratio. - The interaction between planting dates and biofertilization treatments had
significant effect on root diameter (in the first season), foliage fresh weight in the
second season (at harvest), juice purity (in the first season only), root, top and
sugar yields.           -    The interaction between nitrogen levels and biofertilization treatments had
significant effect on all yield components, yield quality and yield except root /lop
ratio, TSS treatments had Significant effect on root diameter, root and foliage fresh weights,
root and top yields.