Let
G
G
be a connected reductive algebraic group over an algebraically closed field of characteristic
p
>
0
p>0
,
Δ
(
λ
)
\Delta (\lambda )
denote the Weyl module of
G
G
of highest weight
λ
\lambda
and
ι
λ
,
μ
:
Δ
(
λ
+
μ
)
→
Δ
(
λ
)
⊗
Δ
(
μ
)
\iota _{\lambda ,\mu }:\Delta (\lambda +\mu )\to \Delta (\lambda )\otimes \Delta (\mu )
be the canonical
G
G
-morphism. We study the split condition for
ι
λ
,
μ
\iota _{\lambda ,\mu }
over
Z
(
p
)
\mathbb {Z}_{(p)}
, and apply this as an approach to compare the Jantzen filtrations of the Weyl modules
Δ
(
λ
)
\Delta (\lambda )
and
Δ
(
λ
+
μ
)
\Delta (\lambda +\mu )
. In the case when
G
G
is of type
A
A
, we show that the split condition is closely related to the product of certain Young symmetrizers and, under some mild conditions, is further characterized by the denominator of a certain Young’s seminormal basis vector. We obtain explicit formulas for the split condition in some cases.