UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
August
18,
2004
Dear
Stakeholder:

The
Agency
recently
received
a
number
of
letters
from
grower
groups
requesting
changes
to
the
mitigation
proposed
in
the
diazinon
IRED,
which
was
signed
in
2002.
Specifically,
these
requests
pertained
to
grapes
and
Brussels
sprouts.
The
purpose
of
this
letter
is
to
acknowledge
receipt
of
these
public
comments
and
address
them.

Five
growers
submitted
comments
regarding
the
Agency's
decision
to
remove
from
the
label
foliar
applications
of
diazinon
to
Brussels
sprouts.
The
dominant
message
in
all
of
these
letters
was
that
there
is
a
need
for
diazinon
late
in
the
growing
season
for
control
of
aphids,
because
diazinon
is
the
only
material
with
a
short
PHI
that
has
fuming
activity.
The
growers
argue
that
loss
of
foliar
applications
of
diazinon
would
require
the
use
of
slower
acting
preventative
treatments
and
disrupt
well
established
late
season
IPM
programs
for
aphid
control.
Several
of
the
growers
specified
that
they
use
diazinon
in
combination
with
other
7
day
PHI
materials.

EPA
acknowledges
this
comment;
however,
the
Agency
believes
that
there
are
enough
effective
alternatives
to
diazinon
for
aphid
control.
Acetamiprid,
imidacoprid,
and
pymetrozine
also
have
short
PHIs
and
endosulfan
and
fenpropathrin
have
longer
PHIs.
The
Agency's
database
and
an
informal
survey
done
with
Agency
entomologists
do
not
support
the
need
for
diazinon
for
foliar
treatment
of
Brussels
sprouts.
The
importance
of
diazinon
for
its
fuming
properties
is
unclear,
since
the
benefits
of
foliar
use
of
diazinon
on
vegetables
are
low
compared
to
the
risks.
Therefore,
the
Agency
stands
by
its
decision
to
cancel
foliar
treatment
of
Brussels
sprouts
with
diazinon.

In
addition,
a
grower
group
representing
wine
grape
growers
submitted
a
letter
requesting
that
EPA
allow
grapes
to
remain
on
diazinon
labels
for
control
against
the
Glassy­
Winged
Sharpshooter
and
the
Vine
Mealybug.
The
group
stated
that
continued
pressures
exist
from
Glassy­
Winged
Sharpshooters
and
that
recently
increased
pressures
exist
from
Vine
Mealybugs.
The
group
argued
that
the
grape
industry
has
a
limited
array
of
resources
to
use
for
control
of
these
insect
species,
and
that
a
widespread
infestation
could
result
if
farmers
do
not
have
access
to
diazinon.

EPA
would
like
to
point
out
that
because
neither
the
Glassy­
Winged
Sharpshooter
nor
the
Vine
Mealybug
is
currently
on
diazinon
labels,
allowing
use
of
diazinon
on
grapes
to
continue
would
not
necessarily
result
in
availability
for
use
against
these
two
pests.
In
addition,
there
are
effective
alternatives
available
for
control
of
the
Vine
Mealybug,
namely,
chlorpyrifos,
imidacloprid,
buprofezin,
and
horticultural
oil.
Therefore,
the
Agency
also
stands
by
its
decision
to
cancel
diazinon
use
on
grapes.

If
you
have
further
questions
on
these
issues,
please
contact
Stephanie
Plummer
of
my
staff
at
(
703)
305­
0076
or
plummer.
stephanie@
epa.
gov.
Thank
you.

Sincerely,

Debra
Edwards,
Ph.
D.
Director
Special
Review
and
Reregistration
Division
