Two field experiments were conducted throughout 2001/2002 and 2002/2003
seasons in EI-Fayoum governorate to study the effect 0 f inoculation of sugar beet
seeds (Beta vulgaris L. cv. Farida) with a mixture of nitrogen fixers namely.
Azosp < /em>irillum sp. and Azotobacter sp. and phosphate dissolving bacteria (Bacillus sp.)
under different levels of mineral fertilizers i.e. O. 25, 50 and 100% of the
recommended rates (RR). 150 kg N Ifed. and 30 kg/ P 2 05 / fed. 0 n photosynthetic
pigments. root Quality, yield and its components and anatomical structure as well as
to minimize costs of fertilization and environmental pollution. The main results of this
investigation could be summarized as follows:
Raising the rates of mineral fertilizers from 25 to 100% showed a significant
increase in chl.a, chl.b.cbl.a+b and carotenoids until they reached the maximum
increase (11.42% in chl.a, 35.12% in chl.b, 20.75% in chl.a-b and 175.51% in
carotenoids) with the highest rate of 100% mineral fertilizers treatment compared to
the control. The application of mineral fertilizers decreased significantly sucrose and
purity percentages in the first season as well as purity and recoverable sugar
percentages in the second season in sugar beet plants. Whereas, recoverable sugar
and sucrose percentages in the first and in the second seasons were indifferent to
those of the control; respectively. On the other hand, TSS% increased significantly
with increasing the application of mineral fertilizers from 25 to 100% in the first season
while, insignificant effect was recorded in the second season. Such treatment
increased significantly i mpurities(Na, K and a-amino nitrogen) content and sucrose
loss to molasses % with raising mineral fertilizers levels up to 100% in the first and
second seasons except thai of Na in the second season where the differences among
mineral fertilizers levels are not significant. The application of the highest level of
100% mineral fertilization gave the highest significant increase being. 84.38 and
85.47% for root length, 78.57 and 64.94% for root diameter. 95.14 and 82.80% for
root yield tonlled., 45.71 and 42.11% for top yield ton/fed. and 74.01 and 43.42% for
sugar yield tonffed. in both studied seasons; respectively.
6iofertilization treatments had significant effect on chl.a. chl.b, chi. a+b and
carotenoids of sugar beet leaves by 1.51. 2.20. 2.17 and 10.68% more than the
control; respectively. On the other hand, showed insignificant effect in sucrose, purity
and recoverable sugar percentages in both seasons except that of sucrose and purity
percentages which were decreased significantly in the first season. Whereas. such
treatment showed significant increase in T55% in the first season and no statistical
effect in the second season. Biofertilization treatment increased significantly impurities
(Na. K and a-amino nitrogen) and sucrose loss to molasses in both studied seasons