| dc.description.abstract | Study on the roles of nitrogen and potassium to phosphoenolpyruvate carboxylase (PEP-Case) activity in the
leaves of ratoon crop of M 442-51 and PS 60 cane varieties were conducted in the Indonesian Sugar Research
Institute (ISRI) Pasuruan, East Java. The experiment was arranged in a factorial trial using a completely ran-
domized block design with three replicates. The factors used as a treatments in this experiment were: (1) sugarcane
variety,
i.e. M
442-51
(V1)
and
PS
60
(V2),
(2)
plant
category,
i.e.
plant
crop
(PC)
and
second
ratoon
crop
(RC2),
(3)
dosage
of
nitrogen,
i.e.
1 q AS/ha
(N1)
and
8 q AS/ha
(N2),
and
(4)
dosage
of
potassium,
i.e.
1
q
KCl/ha
(K1)
and
5 q KCl/ha
(K2).
PEP-Case
activity
variable
was
observed
on
0,
1
and
4
weeks
after
treatment
(wat).
The
results
of
experiment
showed
that
nitrogen
(N)
and
potassium
(K)
nutrients
as single
or
mixture
treatments
were increasing
the
activity
level
of
PEP-Case
in
the
cane
leaves
significantly.
There
was
indication
that
the
effect of
N
is stronger
than
that
the
effect
of
K
to
PEP-Case
activity
in
the leaves
of
cane.
On
the
other
hand,
it was
found
that
the
activity
of
PEP-Case
in
M
442-51
was
higher
than
that
on
PS
60.
However,
when
the
availability
of both
nutrients
was limited,
the
decreasing
activity
of PEP-Case
on
PS
60
was
sharper
than
that
found
on
M
442-51. Study
on
plant
category
showed
that
the
activity
of
PEP-Case
on
PC was
higher
than
that
found
on
RC2.
Reducing
of
PEP-Case
activity
on
RC2
was
predicted
as one factor
that
caused
reducing
of
RC2
productivity.
Base
on
these
findings,
it can
be
concluded
that
PEP-Case
activity
model
in
the
leaves
could
be
used
as an
early characteristic
of
cane
ratooring
ability. There
were indications
that
the
ability
of
both
Mn
and
Cu
nutrients
affected
the
increasing
of PEP-Case
activity
better
than
that
influenced
by
N and
K
nutrients,
but
it
needs
further
investigation. | en_US |
