Two field experiments were conducted in 2008/2009 and
2009/2010 seasons in Sakha Agricultural Research Station, Kafr ElShiekh Governorate. The main goal of this study was to investigate
the response of five multigerm sugar beet varieties (Florima,
Cleopatra, Heracule, Avantage and Alamas) to three sowing dates (1st
Sept., 1st Oct. and 1st Nov.) and three harvest ages (180, 195 and 210
days after sowing). A split plot design with four replications was
devoted for each sowing date where harvest age was allocated in the
main plots and varieties in the sub-plots. A combined analysis over the
three sowing dates and two seasons was undertaken.
Sowing dates markedly affected sucrose and purity
percentages as well as root and sugar yields/fed. Over both seasons,
sugar beet sown early on the 1st of Sept., and/or 1st Oct. recorded at
par the highest root and sugar yields/fed. Sugar beet varieties differed
significantly in their yield potential. Cleopatra variety recorded the
highest sucrose %, while Florima and Heracule varieties produced the
highest root and sugar yields/fed. Harvesting sugar beet after 210 days
from sowing was the proper age to obtain the highest sucrose and
purity percentages as well as root and sugar yields/fed. The interaction
between sowing dates and varieties exerted a significant effect on root
yield/fed. Florima variety recorded the highest root yield in the early
sowing date (1st of Sept.), while Cleopatra and Avantage varieties
recorded their maximum root yields when they were planted in the
second sowing date (1st of Oct.). The interaction between sowing date
and harvest age significantly affected almost all the studied traits.
Regarding this interaction effect on sugar yield/fed, the
response equations indicated the need for more delay in harvest than
210 days after sowing particularly for the early sown sugar beet in 1st
of September. Under the conditions of this work, sowing Florima and
Heracule varieties on the 1st of Sept. or 1st Oct. and harvesting them
after 210 days from sowing can be recommended to obtain the highest
root and sugar yields/fed.