Welcome to the Grower Pesticide Safety
Course. This is Chapter 18, Drift of
Pesticides. Chapter 18 starts on page 179
of the manual. There are 22 slides in
this presentation and it will take us about
20 minutes to review. By the end of this
lesson you will be able to define drift,
describe how nozzles and spray droplets
affect drift, list ways to manage drift
considering equipment, environmental
conditions, and the pesticide. Drift is
the movement of pesticides through the
air, away from the target area. There are
two types of drift --  spray drift and
vapour drift. Our goal is to get the
pesticide from the application equipment
to the intended target and avoid harmful effects to adjacent crops, nearby
plant and animal life, and areas of human
activity. Spray drift is the movement of
spray droplets away from the target area during the application. Small droplets
drift more easily than large droplets.  Granules and powders drift as well.  For
example, pesticide particles drift when
planting treated seed. Sometimes the
pesticide granules and the treated seed
will come off as a planter goes through
the field. So we need to prevent spraying
or particle drift. Vapour drift is the
invisible movement of pesticide vapors
from the target area. So you really won't
see vapour drift happening but vapors
will be released from some pesticides
more than others and some pesticides
change into the vapor state
after a period of time in the soil, air or
on the plant. Pesticide vapors may travel
several kilometers.
Factors affecting spray drift. We're
going to look at equipment, nozzles
travel speed, pressure, nozzle to target
distance, and specialized equipment. Then
we'll talk about the environment, wind
speed, wind direction, temperature
relative humidity, sensitive areas to
watch for, and we'll also think about the
pesticide. There are more volatile
formulations. There are adjuvants we
could add to a product so it's less
volatile or to reduce spray drift and
we'll go over reading the warnings on
the pesticide label. So first the nozzles.
The nozzles are the most important way
to manage drift. Managing drift starts
with that initial size of the spray
droplet when it comes out of the
application equipment.  And small droplets
drift further than large droplets.  The
initial droplet size is determined by
the type of nozzle and of course the
operating pressure, it must run at. So we
need larger droplets.  So we need to use
nozzles that will produce those larger
droplets. Now let's talk a little bit about the
spray nozzle classification. On the right
hand side you'll see the colors and the
categories of droplets from nozzles.  So we
go from very fine, fine, medium, coarse,
very coarse, extremely coarse, and now we
even have ultra coarse nozzles. And they
are color coded to what's in the catalog. So you can look aside and see a
depiction of the catalog there. If we're
looking for coarse nozzles coarse
droplets from a particular nozzle. So we
look over and we can see all the blue
with the letter C in them
and we be able to go in and buy a coarse
nozzle that gives us a coarse droplet. Pesticide labels will state the droplet
size that must be used, so look on the
pesticide label. Most labels will say
medium to coarse. Now we have some label
saying very coarse, extremely coarse, and
ultra coarse nozzles. Nozzle description -- 
what do the letters and numbers mean?
Example, here's an AI 110 04 VS.  So the
AI means air induction --  the air mixes
with the spray liquid and it's going to
produce that larger droplet for us. 110
is the spray angle of 110 degrees -- the
angle that it's coming out of the nozzle.
All the droplets make an angle of 110
degrees. O4--0.4 US gallons per minute
that refers to that nozzle rate, the flow
rate of the nozzle and V S is the
material that it happens to be made of.
This is a visi flow stainless steel
hence the V S as the short form for the
material of the nozzle. So that's what
the letters and numbers mean. The color
of the nozzle represents the nozzle rate.
For example, the red nozzles have a
nozzle rate of 0.4 US gallons per minute.
So this is a different colour code than
the one for the droplet size that
relates to the catalog colours. This is
the actual colour of the nozzle and that
relates to the U.S. gallons per minute
flow rate. When choosing nozzles don't
confuse a nozzle rate colour code with
the droplet size colour code. All right.
Operate nozzles at pressures
recommended to give you the spray
pattern and the angle you need. Spray
droplets change
size with pressure. Higher pressures
usually create the smaller droplets. And
use the pressure recommended for the
nozzle. There may be specialty nozzles
and to get the exact size of the droplet
that you need, you need to follow the
recommendation of the pressure for those
particular nozzles. Spray angle 80
degrees or 110 degrees. Nozzles with that
110 degree spray angle allow the boom to
be closer to the target than the 80
angle nozzles so you're able to reduce
drift, you're just getting the nozzle a
little bit closer to the target. Travel
speed and nozzle the target distance -- two
other things regarding your equipment
that can help you manage drift. With
travel speed, a faster travel speed
could increase drift because this faster
speed creates the air currents and could
break the droplets up into smaller
droplets and distort the pattern before
it gets to the target. And talk about
target, position the boom at the height
recommended for the nozzles. The height
usually recommended for a 110 degree
nozzle is 50 centimetres, 20 inches
above the target. For air blast spraying,
position to match the profile of the
target and redirect the spray for
different crops of different heights.
Specialized equipment, the last thing
under equipment we'll chat about, there
is some specialized equipment you can do
which can eliminate and reduce your
drift.  So wick weeders can be used across the
field. You're wiping the pesticide onto
the higher weeds. Deflectors over the
boom. Perforated screens and nozzle hoods -- They're all available helping to get
reduce the drift. I'm going to also
mention planting treated seeds. Soil
particles become contaminated with
pesticides when planting treated seed
with especially the vacuum planters, so
adjust your planter by mounting the air
intakes for the vacuum meters up high
out of
way so the field dust doesn't enter the
planter system, where field dust will will
pick up the pesticide residues. So be
concerned as well when you're planting
treated seed and that there's actually
drift happening, pesticide drift
happening, at that time as well. Wind
speed --  we're talking about some of the
weather conditions now, and apply when wind speeds are light to moderate
and we're usually talking between two to
ten kilometers per hour and if you're
still thinking, miles per hour,
two to six miles per hour, higher wind
speeds of course increase the chance of
drift. You need some wind when spraying.
There's a danger of drift with no wind. So you want some circulation. When there
is no wind spray droplets can hang like
a cloud or fog and stay suspended so we
don't want that to happen we want the
you know droplets to get down to the
target to the plant so if wind develops
later the spray cloud may blow off
target so we need a little wind to
prevent this cloud that may happen.
Best practice: delay spraying
until there is some wind movement
happening. Now best to measure
your wind speed. Measure the wind speed
at the boom height with the wind meter.
Write it down to keep a record. Do this
for each application not first thing in
the morning not at lunchtime not at 5
o'clock but each time and maybe every
hour in the field would even be good.
Look for signs of wind speed so you can
have a flag with you -- a flag in the field
and look for signs of wind speed. Flags
waving slightly,leaves are rustling, okay,
green light, good for spraying. If we're
at the stage where the flag is straight
out and there's small tree swaying,  this is
not the best wind speed.  So red light and
don't spray. Wind direction, spray
when winds blow away from sensitive
crops and public areas. So in this case,
on a diagram here we have wind coming
off the lake, off the creek and it's
blowing this way, away so then you know
your any drift that would happen
would be direct blowing away from the
sensitive area. Use a compass to
determine the wind direction and write
it down. Feel the wind in your face then
point the compass into the wind to take
the reading. That's how you would do a
reading for direction. Keep monitoring
the wind direction. Stop when the
direction shifts towards sensitive areas.
You want to make sure you're always
spraying where the wind is coming off of
those sensitive areas. Temperature and
relative humidity -- Drift can increase on
a hot dry day when temperature is high
relative humidity is low you have a very
hot dry day. On hot dry days spray
droplets will evaporate quickly and they
become smaller so that's the danger
if it's a really hot drying day
Spray when the relative humidity is
above 70 percent. Surface inversions can
cause drift and several hours after
application so we have to be very
careful with surface inversions. Cool
dense air near the ground is trapped
under a layer of warm lighter air. So spray droplets may float like a fog
over the treated area. We talked about
this a little bit earlier. So delay
spraying in the morning until
temperature has risen by two or three
degrees and winds start to move the air. So again we need some air movement
happening if it's really dead calm this
is not the time to spray, you're
probably in temperature or surface
inversion. And this is when there's cool
air and it is trapped by that warmer air
on top. Sensitive areas --  buffer zones are
areas that are left untreated to protect
sensitive areas. Read the label for
buffer zones you need to use. There will
be a buffer zone chart under directions
for use. So terrestrial habitats, 
terrestrial means land habitats, so wood
lot, pastures, shelter belts.
Freshwater habitats- lakes, rivers, ponds,
marshes. There could be two different
buffer zone requirements  -- one for the
land terrestrial habitats or one for the
freshwater habitats.  So check that on a
pesticide label and then make sure that
you are leaving that buffer zone when
you're spraying. Drift awareness --  spray
drift awareness zones on a map of your
farm quickly identify sensitive areas
within an area of one kilometre of the
area you plan to spray. So do this ahead
of time and think through how your farm
is situated next to other things. And in
this case, we can see there's a
residential area, there's a golf course,
there's a sensitive crop, open water and
species at risk. All things that you need
to be thinking about that's surrounding
you. And note that droplets could move beyond
even this one kilometer zone but if you
even examine your area within one
kilometer and think about ways you can
manage the drift and prevent drift from
these sensitive areas. Know the
characteristics of the pesticide. This is
the last thing we're going to talk about
and we've just got two more slides left. Know the characteristics of the
pesticide. Volatile formulations  -- choose
formulations with low volatility to
prevent drift and if you're using a
volatile formulation, do everything you
can to reduce the drift. Read the label. Follow the label directions. Dicamba
is a herbicide that is known to drift. Dicamba product formulations have been
improved over the years to help reduce
drift. but do follow that label. Adjuvants
-- an adjuvant could affect droplet size
and reduce drift. Use an adjuvant
when the label directions state to use
an adjuvant. And label statements about
environmental hazards. Those will be
under the precaution section on the
label. And buffer zones will be under
directions of use and you will find
those there, droplet size warnings, boom
height, positioning of that boom can be
a statement on the label, wind speed and
temperature, so look for all those
environmental factors and stay within
what the label recommends for that
pesticide. If you do have a pesticide
drift incident on one of your sensitive
crops, to report a pesticide drift
incident phone the district office of
the Ontario Ministry of the Environment
and Climate Change. Outside of the hours
of 8:30 to 5:00 p.m. you can call the
Spills Action Center but best if you
want to search online for the phone
number of the MOECC district office
for your area. Just put that those words
in your search and you will find the
district office that will respond to
your area and you can report your drift.
And that's it, we have to be really
careful about spraying pesticides. We
want to get our pesticides where they
need to be so a lot to think about
with conditions of the equipment and
the conditions of the weather and also
the pesticide we're using.
