This video will show you how to downward
spray a pesticide using water.
You will need your pesticide label
your knapsack sprayer and nozzle; clean
water;
canes or sticks; and personal protective
equipment
as directed by your pesticide label.
From the pesticide label you will know the amount of pesticide to be applied;
the water volume rate to use and the type of nozzle advised.
You will have used some of this information to find out the size of nozzle you will need
and so will now also know your row or swath width;
your comfortable spraying
speed; the nozzle flow rate and
the pressure of the knapsack sprayer.
In this demonstration the label advises us to use a hollow cone nozzle to
spray smaller 'Fine' drops
and we will use 200 ml of a contact insecticide
in 400 L of water to control the pest.
We have calculated that the nozzle size
we need has
a flow rate of 1.2 L/minute; the swath width produced by the nozzle is 0.5 m
and the sprayer will be pressurized 2.3 bar.
Our operator will be spraying with the
nozzle 50 cm from the foliage
at a speed have 1m/second or 3.6 km/hour.
When practicing spraying only use clean
water
and wear your PPE so that you
get used to wearing it
and can adjust it so that you are
comfortable.
When spraying downwards pull your coverall or long sleeve out and over the glove
so that the glove is worn inside the
sleeve.
Some pesticide labels will permit the use of
long sleeved shirt and trousers as dedicated PPE.
A better option is to wear to a coverall.
This knapsack has already been cleaned
checked and calibrated.
If you are not familiar with how to do this please have a look at our separate videos.
As you approach the start point of the
row to be sprayed,
walk at your preferred spraying speed -
the speed which you used to calibrate your sprayer.
As you reach the start point, start spraying
with your nozzle 50 cm from the foliage.
Walk slightly to one side of the spraying nozzle
to avoid contact with the sprayed vegetation.
If you are spraying a band or row,
spray only the target surfaces. For instance,
adjust your swath width so that only spray
the crop row or the row of vegetables.
If possible spray with the wind at your back
blowing from you towards the nozzle.
Monitor your spraying pressure
and keep your spraying speed constant.
Constantly check that your nozzle is producing
the right spray pattern and drop size.
Check that the spray is reaching the target surfaces.
Avoid spraying too much pesticide
so that the drops run off the leaves.
This is too much.
Check that spray is reaching the leaves
of the potato canopy that are lower down,
as well as those at the top of the canopy.
Contact insecticides and fungicides
will only control the pest where the spray has made direct contact with the pest.
So check that every leaf and stem
that is sprayed, has a cover of drops over the entire surface.
Contact herbicides also need an even coverage
over all of the weed.
You can use the same techniques for the spraying of
systemic herbicides, however there is an
opportunity with all systemic pesticides to use
larger drops rather than the smaller sizes.
The spraying of larger drops of systemic sprays will be safer for you
as you are less likely to inhale the
droplets and safer for the environment
as large droplets are less likely to drift.
When air is coming out the nozzle and the spray liquid is
all used, place a stick at this point. This will mark the
point where spraying will continue with the next load.
Leave a small un-sprayed area which can
be sprayed later with the water used to
clean the inside of the sprayer.
© 2015, Syngenta. All rights reserved.
