The Conservation Farming Unit
CFU established in Zambia in 1996 – www.conservationagriculture.org
Spraying and Herbicide Information Booklet
Whilst the Conservation Farming Unit does not formally promote the use of specific herbicides or
other Crop Protection Products (CPP), farmers know from their own use of these products, whether
in Conservation or Conventional Farming systems, that herbicides, when applied correctly will save
many hours of backbreaking labour. For farmers who correctly apply these products there are
substantial reductions in time and cost when compared with paying hired labour for hand weeding.
Commercial suppliers and manufacturers have made herbicides and other CPP widely available in
Zambia and across the region and many farmers are now purchasing and using them routinely on
their farms, often without the benefit of adequate training.
Farmers, whether CF or Conventional, will and do use these products as part of a farming system to
increase cash generated and therefore to enhance their family’s quality of life. As one of the largest
and most experienced providers of CF training in Zambia and beyond, it would be irresponsible on
the part of the CFU not to provide the training farmers need to apply CPP correctly and safely.
The CFU continues to provide comprehensive herbicide and sprayer use training to all of its staff. This
training is passed on by the CFU Field Officers to the Farmer Co-ordinators who in turn pass this
knowledge to all farmers who attend their training sessions. These training sessions are open to all
who wish to attend and are free of charge. Many MAL staff members and staff from other NGO’s
have benefited from this thorough and interactive training.
This handbook has been produced by the CFU as a summary of the safe use and correct herbicide
application training already provided to many thousands of farmers and spray operators and is not
intended to be a substitute for face to face training.
2
Knapsack Sprayers
Before considering the herbicides that are
available to control weeds in field crops grown in
Zambia, we must first become skilled in the
correct way to apply these products using a
knapsack sprayer.
When choosing a knapsack sprayer it is important
that a good, well made sprayer is chosen. Do not
buy poor quality. A good quality sprayer will give
many seasons of service, a cheap bad quality
sprayer may last only one or two seasons, “buy
cheap, buy twice”! Spare parts for good quality
sprayers are normally available from the main
supplier. This may not be true for cheaper
sprayers.
Opposite are some examples of good quality
sprayers.
3
The External Components of a Knapsack Sprayer
1. Trigger valve
2. Pressure control valve
7. Delivery tube
3. Pump
8. Tank lid
4. Pump handle
9. Spray tank
5. Lance
6. Nozzle holder and nozzle
4
How Do Knapsack Sprayers Work
The heart of a knapsack sprayer is the pump (3*). The pump is situated inside the spray tank (9*) and is
worked by the operator moving the pump handle (4*) up and down. The upwards movement of the
handle will bring diluted chemical from the tank into the pump, the downwards movement of the handle
compresses this liquid inside the pump. Some operators will place a piece of plastic under the tank lid to
seal it as they think that pressure will be lost here but the tank is never under pressure. There is a nonreturn valve in the lid which if sealed in this way will not be able to operate and will interfere with the
proper functioning of the sprayer.
When the trigger valve (1*) is squeezed open by the operator, the compressed diluted chemical is
allowed to flow from the pump, through the delivery tube (7*) and via the trigger valve filter through
the lance (5*) to the nozzle holder (6*). The diluted chemical then flows through the filter in the nozzle
holder and to the nozzle (6*) where it is broken up into droplets to form a spray cloud. Some sprayers
are fitted with a pressure control valve (2*). This device maintains a constant pressure at the nozzle even
if the sprayer is pumped too fast, if the sprayer is pumped too slowly the valve will shut off the flow of
the product to the nozzle.
For details of how to spray see pages 9 - 11 of this booklet.
For sprayer operator training contact your nearest CFU office (see contacts on page 27).
* The numbers above refer to the numbers
on the diagram on page 4
5
Filters
There are three filters fitted in most quality knapsack sprayers which help to prevent the nozzle from
becoming blocked. These filters must always be in place and must always be kept clean or the sprayer
may not function correctly, daily cleaning is recommended. Be very careful not to cross-thread when
replacing the trigger valve or the nozzle holder, if this happens the sprayer will leak, involving an
expensive repair.
The first filter is a sieve
and is found under the
tank lid (8*)
The second filter is usually found
inside the trigger valve (1*)
The third filter is situated in the
nozzle holder behind the nozzle (6*)
This type of filter is known as a “top
hat” filter.
* The numbers above refer to the “External
Parts of the Sprayer” diagram on page 4.
6
Nozzles
The most important part of any sprayer is the nozzle. A variety of nozzles are available from retail
outlets, it is essential that you buy the right type. Different nozzles are used for different purposes and
for different products. One type is used for insecticides, fungicides and spraying animals only; this type
of nozzle is known as a hollow cone nozzle, it must never be used for spraying herbicides.
Flat Fan Nozzles
Hollow Cone Nozzle
Above is the hollow cone
nozzle; this must never be
used
for
applying
herbicides
The correct nozzle
must be used or
money will be
wasted by applying
either too much
herbicide,
which
could cause crop
damage, or too
little which will lead
to
poor
weed
control.
These are the nozzles that the CFU
recommend for the application of herbicides
with a knapsack sprayer. These are known as
flat fan nozzles
7
A nozzle will not last for ever, they are usually made of plastic and will wear out. The nozzle outlet hole
will get bigger with use, as it gets bigger it will emit more liquid, wasting product and your money. You will
save money by buying new nozzles every other season.
If a nozzle becomes blocked the
blockage must be cleared:
 Never blow through the nozzle to
clear it, if this is done herbicide will
get in your mouth and possibly
your eyes, this is dangerous.
 Never use a wire or a pin to clear a
blocked nozzle. Nozzles are
manufactured
to
very
fine
tolerances, if a hard point is used,
the nozzle opening will be enlarged
and distorted; the output of that
nozzle and the spray pattern will be
altered making that nozzle
effectively unusable.
To unblock a nozzle, drop it
into a bottle, add some clean
water and shake the bottle.
Remove the nozzle and hold it
up to the light, if the blockage
is still visible push the
blockage back through the
nozzle opening with a clean
grass stalk, check the outlet is
clear and wash the nozzle
once more in the bottle with
clean water.
8
How to Spray Correctly
When spraying the operator must walk at the correct speed.
Walking too fast will result in a low rate of herbicide being applied,
walking too slowly will result in a higher rate of herbicide being
applied.
CFU Operator Training; Using Clean
Water Only
To walk at the correct
speed; hammer two pegs
50 meters apart into the
ground in a nearby open
space. Fill the sprayer
with clean water only. Ask
a friend or colleague to
time you as you walk
between the two pegs.
You are walking at the
correct speed if you walk
the 50 metres in 45
seconds.
Align
nozzle
correctly
Direction
of travel
The nozzle slot must be set at
right angles to the direction of
travel.
Keep your nozzle clean, do not let
it drop in the soil when you are
not spraying, as this will cause
nozzle damage or blockage.
It will take time and
practice to get this right
every time.
9
The operator must also pump at the right speed, too fast
pumping will result in too high a rate of herbicide being
applied, too slow pumping, too low a rate.
To learn to pump at the right speed
you will need a helper, a measuring
jug and a stop watch. Fill the sprayer
with clean water only, place the
measuring jug under the nozzle,
open the trigger valve and pump
with a steady slow action into the
cylinder for one minute, measure the
result in millilitres (cc’s).
If using the orange nozzle you should
pump 300mls into the cylinder in 1
minute, for the blue nozzle pump
1200mls in 1 minute.
CFU Sprayer Operator Training
You can make a measuring jug from
an empty 2litre plastic bottle. Using
the measuring cup that is included
with your new sprayer. Measure
300mls of water into the bottle and
make a mark on the outside with a
permanent marker, add another
900mls and make another mark; 300
+ 900 = 1200mls, as above.
10
The nozzle must be held at the correct height above the target. The target will be either the weeds or the
ground depending on which herbicide is used, this will be explained later in this manual.
The correct height above the
target for crops grown in 90cm
rows and when using a flat fan
nozzle is 50cms.
To make a guide for nozzle
height; use a weight, an old car
wheel nut is perfect, and a
length of string. Tie the string to
the weight.
Cut a piece of timber to exactly
50cms. With a helper, place the
nozzle on top of this and tie the
string with the nut attached,
behind the nozzle holder so that
the nut just touches the ground
when the nozzle is resting on the
timber. The nut should brush
along the target whilst spraying
this will ensure a nozzle height
of 50cms.
CFU Spray
Operator Training
Setting the Correct
Nozzle Height
After
you
have
perfected
both
walking speed and
pumping speed one
after
the
other,
practice walking and
pumping
together
whilst also holding
the nozzle at the
correct height, all at
the same time. This is
not easy but practice
makes perfect.
50cms
11
Categories of Herbicides
There are many different types of herbicides which have specialised uses in crop and non-crop situations.
If you use the wrong herbicide you may damage your crop.
Herbicides are either selective (these herbicides will kill the weeds and not the crop) or non-selective
(these herbicides will kill most green plants). Non-selective herbicides, if sprayed on to your crop, will kill
or severely damage it.
Systemic
herbicides will
move through the
plant’s system,
from the site
where they settle
on the weed,
through the
leaves into the
roots, killing the
whole plant.
Herbicides are also either
systemic or contact
Droplets of herbicide
Soil level
Contact
herbicides do
not move
through the
the plant,
complete cover
of the weeds is
essential for
total kill.
Root System
12
Herbicides are sprayed either pre or post emergence of the crop, the weeds or both.
Pre-emergence herbicides are sprayed before the crop or the weeds or both have emerged from the
soil, they usually work in the soil by killing the germinating weed seedlings.
Post-emergence herbicides are sprayed after the emergence of the weeds or the crop or in some
cases both.
Always follow the product manufacturers label recommendations for the correct amount of
chemical and the correct time to apply.
Finding the right herbicide for the correct crop situation is complicated, it is
essential that the right product is chosen and applied safely and accurately. The
CFU Field Staff have been comprehensively trained in the use of herbicides and
sprayers and will be able to advise on which herbicides to use in most crop
situations. The CFU Field Staff also offer sprayer and application training.
Contact the nearest CFU office for herbicide training before choosing and
applying any herbicide.
See page 27 for the contact details of your nearest CFU office.
13
The image below shows the damage that can be done to a potentially good crop by uninformed,
untrained spray operators using herbicides.
Training in the use of herbicides and in sprayer operation is essential before attempting to use these
products.
See page 27 for the details of the CFU office in your area where advice can be sought and training
arranged.
Severe Crop Damage Caused by an Untrained Spray Operator
14
Herbicides Used in CF
Pre-planting Herbicide - Glyphosate
Glyphosate is one of the most used and most useful
herbicides in CF. Known by many trade names; Round Up
is probably the most well known name for this product.
Glyphosate is a post- emergence, non-selective*,
systemic* herbicide.
CF farmers use glyphosate to kill weeds, both annual and
perennial, pre-planting of any crop. It could be said that
glyphosate replaces the weed control gained by the
turning of the soil by the plough or the hoe. The
difference is that once the weeds are treated with
glyphosate they will not grow back, even perennial
grasses and their rhizomes, if sprayed correctly, will be
completely killed.
Glyphosate is deactivated on contact with the soil,
therefore only the weeds that you can see that have
emerged from the ground will be killed.
If a pre-planting spray of glyphosate is the only treatment
that you will use, you may also need to hand weed your
crop once during the growing season.
Glyphosate should be applied after the
first rain showers have induced some weed
growth and just before planting the crop.
Read the product label for rates to use.
Always use an orange nozzle for the
application of glyphosate.
Remember to walk and pump at the
correct speed. (Refer to page 10).
Never spray your crop with
glyphosate, it is non-selective and
will kill your crop if it is sprayed with
this product.
Never spray onto wet weeds.
Do not spray if rain is expected,
Glyphosate needs at least 4 hours of
dry weather after spraying to work.
Glyphosate may take up to 2 weeks
to completely kill weeds
*Refer to page 13 for
explanation
15
Inter-Row Weeding Herbicide
Paraquat
Although a useful tool, paraquat is a very toxic chemical to humans and animals. There is no
antidote for paraquat, if it is drunk it will kill. Do not use paraquat or any other herbicides
without being trained in their use. As a precaution the CFU does not recommend or promote
paraquat but will advise farmers on its use if it has already been purchased.
Paraquat is marketed by many companies in Zambia under the names of Gramoxone, Muparoxone,
GAP paraquat and as just Paraquat, amongst others. Unfortunately paraquat is very similar in colour
to most cola drinks, making it imperative to keep this product out of the reach of children.
The manufacturers of Gramoxone included a number of safety additives many years ago; a colour, a
stench, a thickener and an emetic (vomit inducer). These additives help in distinguishing Gramoxone
as different from a cola drink but may not save a life if the product is drunk.
Read the safety instructions on pages 24 - 26 of this booklet and approach CFU staff for training
before attempting to use paraquat or any other herbicide.
Paraquat is a non-selective, non-systemic, post emergence herbicide. The main use for paraquat in
CF in Zambia is for inter-row weed control mostly in maize, as a “chemical hoe”. The maize must be
0.5 - 0.75m high before paraquat can be used inter-row
This product can also be used as a pre-planting herbicide but as it is a contact, non-systemic
herbicide it will not kill perennial weeds.
16
Paraquat: continued
For inter-row weed control use the blue
nozzle, held low between the maize rows. As
paraquat is a contact, non-systemic herbicide,
any chemical that does come into contact with
the bottom leaves of the maize will kill only
those leaves, not the whole plant.
Most annual weeds will be killed, perennial
weeds will re-grow but may be shaded out by
the crop for the remainder of the season.
One person can easily spray 0.5 of a hectare,
inter-row, in a working day. Hand weeding of
the same area would take 8 – 10 days (CFU
figures), there are therefore, potentially
substantial savings in time and cash to be
made by using chemical weed control instead
of hiring labour for hand weeding.
The Effect of Paraquat When Used as an Inter-row
Herbicide
17
Maize Herbicides
Blazine, Maize Weed Killer and Excel
These products contain the same two chemicals, atrazine and cyanazine. They are selective, pre or early
post emergence, systemic herbicides for maize only.
Atrazine will control many annual broad leafed
weeds whilst cyanazine will control many
annual grasses. This product will not control
perennial weeds such as kapinga.
The chemicals in this product will continue to
kill germinating weed seedlings for up to 8
weeks, long enough for the maize to shade out
new emerging weed seedlings.
These products work best if they are sprayed
immediately post planting of the maize. They
work by killing the germinating weed seedlings.
The soil must be moist when sprayed (as it will be
if sprayed immediately post planting) and must be
followed by rain within 7 days to work effectively.
Follow the label instructions as to the rate of
product to use per hectare. This will vary with soil
type.
How to Use These Maize Herbicides
First, spray with glyphosate to kill the weeds
pre-planting of the maize using the orange
nozzle. Spray again with atrazine/cyanazine just
post planting. Using this method most of the
annual broad leaved and grass weeds will be
controlled for the duration of the maize crop.
This will save much time, labour and cash, giving
you a much better profit from your crop.
This product can be sprayed post emergence of
the crop and weeds but never after the four leaf
stage of the maize crop.
Use the blue nozzle to spray these products.
18
Maize Herbicides
Stellar Star
Stellar Star is a selective, systemic, post emergence herbicide for maize only. The active ingredients of
Stellar Star are topramesone and dicamba.
How to Use Stellar Star
Spray with glyphosate, pre-planting of the maize, to kill the existing weeds using the orange nozzle.
Wait until the correct growth stage of the weeds and the maize and spray again with Stellar Star.
Stellar Star works by bleaching the chlorophyll (green colour) of the weeds, disrupting their function
and eventually killing them. Stellar Star is not immediate in action, it will take some days before this is
noticeable.
Stellar Star will control most annual grasses and broad
leaf weeds in maize. It is sprayed post emergence of the
crop and the weeds.
It will not control perennial weeds such as kapinga but
may suppress them long enough to allow the maize to
shade them out for the rest of the season. It is most
effective if sprayed when weeds are at the 3-4 leaf stage
but has a wide application time window.
This herbicide does have some soil residual action, this
will not affect following field crops.
Use the blue nozzle to spray Stellar Star.
The Effect of Stellar Star
19
Soya Bean and Ground Nut Herbicides
Selective Broad-Leafed Weed Herbicide – Classic,
Bean Weed Killer
Classic and Bean Weed Killer (BWK) both contain
the active ingredient chlorimuron ethyl, which is a
post emergence, (of weeds and crop) systemic
selective, annual broad leafed weed killer (BLW)
for use in soya beans and groundnuts.
How to Use Selective Broad Leafed Herbicides in
Soya Beans and Groundnuts
First, spray existing weeds with glyphosate, preplanting, use the orange nozzle. Then spray with
Classic or BWK when most of the weeds have
emerged either on its own or in a tank mix with a
selective grass herbicide; see page 21.
Crop Damage Caused by Spraying Callisto on
Sugar Beans.
This product may be sprayed separately or tank
mixed (two or more products mixed together in
the spray tank) with the correct rate of any of the
grass weed killers described on page 21 to provide
selective control of annual broad leafed weeds
and all grasses in soya beans and groundnuts.
Never use Classic on its own or in mixture with a
grass weed killer to control weeds in sugar beans
or any other crop or damage will be caused.
Use the blue nozzle to spray these products
20
Soya Bean and Groundnut Herbicides - continued
Selective Grass Herbicides - Fusilade and Orca, Pantera, Quizate, Nova and Grass Killer, Miyidima.
Fusilade and Orca contain the active ingredient fluazifop butyl; Pantera, Quizate, Nova and Grass Killer
contain the active quizalofop-P-terfuryl and Miyidima contains the active haloxyfop-P-methyl.
All these herbicides are very similar and are post emergence (of weeds and crop), systemic, selective
grass weed killers for use in broad leafed crops such as soya beans and groundnuts. All of these
herbicides will kill annual and perennial grass weeds including kapinga if sprayed at the correct rate of
product and growth stage of the weeds.
How to Use Selective Grass Herbicides in Soya Beans and Groundnuts
First, spray with glyphosate after the first rain showers, pre-planting, to kill the weeds, including the
perennial weeds; use the orange nozzle.
Plant the crop, wait for the weeds to grow and spray with either a grass herbicide or a BLW herbicide or
a tank mix of the two.
The visible action of these grass weed herbicides will take some time to appear. It may take two weeks
before the effect of these herbicides is visible and will be seen as a reddening of the grass weed leaves.
Use the blue nozzle to spray these products
21
Cotton Herbicides
Cotton Weed Killer and Herbicon
These are two of the products sold in Zambia
containing the active ingredients fluometuron
and prometryn. They are pre-emergence,
selective, systemic herbicides for cotton only,
which will control most annual grasses and
broad leafed weeds, if sprayed correctly. These
products will not control perennial weeds.
Herbicide Treated Cotton
How to Use Cotton Weed Killer and Herbicon
First, spray with glyphosate, pre-planting, to kill
existing weeds, including perennials. Use the
orange nozzle.
Immediately post planting, spray with one of these products. The soil should be moist when these
products are sprayed and rain should be expected within 5 days of application for these products to
work effectively.
Use the blue nozzle to spray selective herbicides in cotton.
22
Cotton Herbicides - continued
Fusilade and Orca, Pantera, Quizate, Nova and
Grass Killer, Miyidima.
If annual or perennial grass weeds are a problem
in cotton these can be controlled selectively, post
emergence of the cotton by applying one of the
above systemic grass weed killers at the correct
rate. These products can be applied at almost any
growth stage of the crop and will even control
kapinga and other destructive perennial grass
weeds if sprayed at the recommended rate.
How to Use Selective Grass Herbicides in Cotton
First, spray with glyphosate, pre-planting to kill
existing weeds. Use the orange nozzle.
When it is thought that most of the perennial
grass weeds have emerged, spray with one of
these products at the label stated rate.
The action of these herbicides is not immediate,
wait for two weeks for the herbicidal action to
show.
A Weed-Free CF Cotton Crop
Where maize is being rotated with cotton and/or
soya beans and groundnuts, perennial grass weeds
can be controlled in the standing crop, effectively
cleaning the field of these weeds before the
planting of the maize crop in the following season.
See page 20 for the list of active ingredients
contained in these products.
Use the blue nozzle to spray these products.
23
Safety
Reading and adhering to safety guidelines is usually considered tiresome, especially by farmers, who
are used to their freedoms.
However, all pesticides including herbicides, can be dangerous to the spray operator,
those that are close by when these products are being used, the operator’s family and the
environment, if these products are not applied correctly.
On the next two pages are rules which must be read and adhered to by farmers and spray operators
and passed on to all potential users of these products by CFU staff, lead farmers and experienced
operators.
Potential operators should not attempt to use crop protection products unless they have been
properly trained.
See page 27 for the details of the CFU offices. Staff will provide free herbicide training.
24
The Safety Rules
 No pesticide or herbicide can ever be described as safe. CPP’s must always be handled with great
care.
 Always read the container label before use.
 Never use a product that is not in the original labelled container or has a broken seal.
 Always wear the correct clothing. Read the label for recommendations Ideally, when handling
concentrated products wear; rubber gloves, overalls, gum boots and eye protection. When
spraying, operators also should wear the above but long trousers, stout shoes (no holes) with
socks, a long sleeved shirt with the cuffs and top button fastened and a hat is usually
recommended.
 Never eat or smoke whilst spraying. Take a break, wash your hands and then eat or smoke.
 If the sprayer develops a leak, fix it immediately; do not continue spraying until it has been fixed.
 After spraying any plant protection products, keep people and animals out of the sprayed area.
Read the product label, it will state for how long to do this.
 Always handle plant protection products in a well-ventilated place, preferably in the open air.
25
Safety Rules: continued
 Never transport or store these products next to food or medicine or cigarettes. Transport and store
these pesticides separately.
 When storing these products, keep under lock and key, outside your house, in a well-ventilated
place and out of direct sunlight
 Never re-use a chemical bottle. It must not be used for any other purpose. Wash the empty bottle
three times with clean water (using roughly 10% of the volume of the bottle); pour these washings
into the sprayer. Destroy the bottle by making holes in it. Dispose of the bottle; the most
convenient method of doing this is to drop it into a pit latrine.
 Never blow through nozzles or filters to clear them of blockages; wash these in clean water (see
page 9).
 Never spray in windy conditions. The product will drift in the wind polluting the environment and
possibly causing damage to neighbouring crops. In a light breeze start spraying from the downwind
edge of the field so that any drift is blown away from the operator.
 After the days’ spraying, take a bath and change your clothes. Wash the contaminated clothes
separately from the family wash.
26
Never use herbicides without professional training.
Without proper training the use of these products could damage your crops and your
health.
The 70 CFU Field Officers and almost 1900 Lead Farmers can train you to use herbicides safely and
efficiently. This training is free of charge; for more information contact your CFU regional office:
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Central Region, Kabwe;
House No. 27, Marshal Avenue Street. P.O. Box 80742
Tel: 05 222343. Cell: 0965238087
Western Region, Mumbwa;
House No: 652, Kalenda Street, Low Density Area, Behind New Bus Station. P.O. Box 830080.
Tel: 0211 800311. Cell: 0965 238086/ 89
Eastern Region, Chipata;
P.0.Box CFU 511013.
Tel: 0216 223663. Cell: 0965238092/93/96
Southern Region, Choma;
Plot 938, Riverside, Choma. P.O. Box 630257.
Tel: 0213 221412. Cell: 0965238034/32
Mkushi;
Plot 745, Prison Street, Medium Cost.
Cell:0965238094/139
Mongu;
ZARI Complex, BOMA Area. P.O Box 910064.
Cell: 0965238039
Senanga;
Plot 227, Mwanambinyi East.
Cell: 0965238053
27
Conservation Farming Unit
Plot 297/A/9/10 Leopards Hill Road, Lusaka, Zambia. Tel: 0965238058
Email: info@conservationagriculture.org www.conservationagriculture.org