Cursory
assessment
of
disulfoton
use
in
coffee
in
Puerto
Rico
By
:
Nikhil
Mallampalli,
BEAD/
HIB
To
:
Christina
Scheltema,
SRRD
As
per
DP
Barcode
#
:
279009
Disulfoton
is
available
only
in
the
15
%
granular
form
for
coffee
production
in
Puerto
Rico.
It
is
registered
under
a
section
24(
c)
label,
for
control
of
leafminers
(
larvae
of
the
moth,

Leucoptera
coffeella
)
.
This
insect,
left
uncontrolled,
can
cause
up
to
50
%
reduction
in
photosynthetic
activity
and
40
%
reduction
in
yield
1
.
As
such,
this
pest
can
pose
a
major
economic
problem,
since
coffee
crops
in
Puerto
Rico
provide
a
gross
income
of
approximately
$

30.3
million
3
.

Of
about
50,000
acres
planted
to
coffee
in
2000,
approximately
15.3
%
(
7,636
acres)

were
treated
with
disulfoton
1
.
The
insecticide
is
also
applied
to
plants
in
nursery
production,

with
an
unknown
amount
of
the
total
product
being
treated.
Treatment
of
coffee
in
the
field
is
carried
out
exclusively
by
government
employees
(
known
locally
as
the
A
Brigades
@
)
,
as
this
is
cheaper
for
individual
growers.
Nursery
applications
are
carried
out
by
growers
themselves
1
.

Rates
of
application
in
fields
vary
according
to
the
age
of
the
plants
involved.
They
are
0.25,
0.5
or
1
oz
for
newly
planted,
2
nd
year,
and
 
in­
production
 
trees,
,
respectively.
This
represents
20
lb
(
=
3
lb
active
ingredient)
,
30
lb
(
=
4.5
lb
active
ingredient)
,
and
60
lb
(
=
9
lb
active
ingredient)

per
acre,
of
granular
15%
disulfoton
2
.

These
estimates
are
based
on
an
assumption
of
1,000
trees
per
acre
2
,
though
some
newer
varieties
can
be
planted
at
1,500
trees
per
acre.
Fields
with
these
(
unspecified)
varieties
would
require
commensurately
greater
active
ingredient
1
.
Nursery
applications
are
broadcast
at
an
approximate
rate
of
0.5
gm
(
=
0.08
gm
active
ingredient)
per
plant.
Plants
in
nurseries
are
kept
in
polyethylene
bags,
3
 
3.5
inches
in
diameter
and
10
inches
deep
1
.
All
applications
of
disulfoton
are
made
using
a
bucket
and
spoon.
This
is
their
time­
honored
method,
and
has
been
used
for
about
37
years
1
.
Early
attempts
to
use
a
 
Swiss­
Mix
 
,
a
belly­
grinder
type
of
spreading
device
used
in
Puerto
Rico
to
apply
aldicarb,
were
unsuccessful,
due
to
rapid
damage
of
the
mechanism
from
the
abrasive
disulfoton
granules
1
.
Growers
and
extension
staff
appear
receptive
to
alternative,
more
closed,
systems
of
application.
It
is
noteworthy
that
the
application
rates
quoted
above
are
based
on
efficacy
studies
done
in
the
1950s,
by
Puerto
Rican
scientists
who
used
a
10
%
granular
formulation
of
disulfoton
2
,
as
opposed
to
the
currently
used
15
%
formulation.

Aldicarb
(
Temik)
is
the
only
currently
available
alternative
to
disulfoton
in
this
crop
that
is
believed
to
have
some
effectiveness
against
leafminers.
It
is
considered
by
growers
and
extension
service
staff
to
be
less
effective
than
disulfoton,
and
was
applied
to
only
about
3,500
acres
in
2000
1
.
Aldicarb
is
also
 
slightly
more
expensive
 
than
disulfoton
1
.
Azadirachtin
is
also
registered
for
use
against
leafminers
and
a
variety
of
other
insects
in
coffee,
but
is
unlikely
to
be
as
beneficial
as
disulfoton,
since
it
has
no
systemic
residual
activity,
and
breaks
down
on
plant
surfaces
rapidly.
The
extension
service
staff
that
were
consulted
do
not
list
it
as
a
control
option
for
coffee
growers
in
Puerto
Rico
1
.

Sources
1.
Acin,
N.
,
R.
Ingles,
and
M.
Monroig.
University
of
Puerto
Rico,
Mayaguez,
PR.

2.
Cibes,
H.
,
and
M.
Perez.
1957.
Informe
Oficial
EEA,
UPR,
No.
33.

3.
Office
of
Agricultural
Statistics
(
OAS)
.
1999.
Gross
farm
income
of
Puerto
Rican
agriculture;
1997­
1998.
Puerto
Rican
Department
of
Agriculture,
San
Juan,
PR.
Pp
20­
21.
