Influence of Potassium Fertilization and Foliar Application of Zinc on Sugar Beet Plants Grown on a Calcareous Sandy Soil

This study was conducted at El-Ghorieb Exp. Farm, Assiut University, Assiut,
Egypt, during 2010/2011 and 2011/2012 seasons to investigate the effect of
potassium fertilization (48 and 72 kg K2O fed.-1) and the foliar spray with three
zinc chelate levels zero, 75, and 150 mg l-1 as Zn-EDTA (15% Zn) on yield and
quality as well as Fe, Mn and Zn contents of sugar beet plants grown on a calcareous
sandy soil.
- All plant characteristics and quality traits of sugar beet i.e., top and root
fresh and dry weights, sucrose content, sugar recovery, recoverable sugar yield,
as well as Fe, Mn and Zn contents were significantly increased by increasing the
K level from 48 to 72 kg K2O fed.-1 in both seasons.
- Increasing the potassium level caused an increase in the sucrose percentage.
Moreover, a remarkable increase in the recoverable sugar percentage was
observed as K level increased. Potassium fertilization showed a significantly increase
on sugar beet yields at 48 kg N fed.-1 level as well as 72 kg K2O fed.-1 for
top yield and recoverable sugar yield.
- With regard to zinc foliar application, significant decreases on impurities
and increases on sugar loss to molasses and sucrose percentage were observed. It
also had an insignificant effect on the recoverable sugar percentage. In most
cases, increasing Zn level up to 150 mg l-1 significantly increased the sugar beet
yields fed.-1
- Potassium fertilization x zinc foliar application interaction had a significant
effect on Na content in beet roots in both seasons. Moreover, significant effects
were observed only on K content in beet roots and sugar losses to molasses
in the first season as well as top yield fed.-1 in the second season. It could be concluded
that application of the K fertilization at 72 kg K2O fed.-1 along with the
foliar application of zinc had a positive effect in increasing all growth traits of
sugar beet