Bow & Arrow Herbicide - Calibrate your Spraying Equipment

Failure to Calibrate your spraying equipment WILL highly likely result in either turf DAMAGE or POOR results.

To understand what Calibration is, (and why dilution rates DO NOT work) read on.


Bow & Arrow Herbicide - How to Calibrate

What is Bow & Arrow Herbicide’s Mixing Ratio / Dilution rate… there isn’t one. That’s right that was not a typo.

Bow & Arrow Herbicide is a product that requires a set amount of product over a set area. There are no dilution rates, dilution rates don’t work… because if 2 people (YOU and ‘John Smith’) were to use the same equipment and do the same dilution rate and John Smith walks twice as quick as YOU then John Smith is under-dosing by half compared to YOU…… or you are double-dosing compared to John Smith.

Therefore, you need to calibrate your equipment, to make sure YOU know what water volume YOU are using over a set area, once YOU know this you can then add the Bow & Arrow rate into the water volume that YOU use for the area. Unless YOU know how much water YOU will use over 100 m2 YOU can NEVER get a set amount of Bow & Arrow evenly over 100 m2. Water is your only carrier and vehicle to apply Bow & Arrow Herbicide, without knowing the water volume YOU spray per 100 m2, YOU can never achieve the Bow & Arrow Herbicide ‘rate per 100m2’ evenly over 100m2, so calibration is a MUST.

If you do not calibrate and you do a mixture of 50 mL in 5L of water but you actually spray at 10 L of water per 100m2, then you will spray at double the rate and you will cause DAMAGE to your turf.

Let us use Bow & Arrow’s 50 mL per 100 m2 rate as an example. 50 mL in 2 to 5 L of water per 100m2. With Bow & Arrow you can spray any water volume between 2 to 5 L of water per 100 m2. Once you have established YOU spray a certain amount of water over a set area (100 m2), you can then add the 50 mL of Bow & Arrow into that volume and spray 50 mL of Bow & Arrow evenly over 100 m2. For example, if John Smith sprays at 4.5 L per 100 m2 then John Smith puts 50 mL in 4.5 L of water to spray 100 m2, if YOU spray at 4 L of water per 100 m2 then YOU put 50 mL in 4 L of water to spray 100 m2.

Once you have established you can spray a set volume over that area, dose the 50 mL into that volume and away you go over 100m2. If using a hand sprayer it’s unlikely you will be able to spray as low as 2L per 100m2, therefore a range of 4 to 5L per 100m2 is what is more achievable.

How to Calibrate Pedestrian Spray Equipment

Spraying straight water on a concrete area is always best as it shows you how even or uneven you are and how little water you need to cover an area well. Your aim should be to simply wet the concrete evenly, DO NOT flood it or make the water run/move, just evenly wet it.

Do a blank run with JUST WATER in the sprayer so you can get your walking speed and spray pattern right. Practice on a concrete driveway (or any concrete) with JUST WATER, measure out a concrete area of 10 m2 (yes that's TEN square metres - i.e. 5 m x 2 m rectangle area or 3.17 m x 3.17 m square area) to calibrate and practice. This will show you how even or uneven you are actually spraying, once you think you are spraying evenly and correctly let the concrete dry, then spray the 10m2 again with water and time yourself with a stopwatch/iPhone.

For this Example, let’s say it took you ‘50’ seconds (we have made up 50 seconds – don’t use this figure to bypass calibrating your equipment), you then put your spray nozzle into a measuring container (i.e. measuring jug) and you turn it on for the same amount of time, in our example ‘50’ seconds, at the same pressure you just sprayed that 10 m2 of concrete evenly, be sure to maintain the same pressure as you did spraying the 10 m2 of concrete (i.e. maintain hand pumping for pressure with manual pressure units).

Let’s say (for our example) you measure 460 mL of water, so you have used;

460 mL over 10 m2.

Which is 4,600 mL over 100 m2.

Which is 4.6 L over 100 m2.

[Note: if you have more than one nozzle (i.e. 3 nozzle boom) either measure volume from all 3 nozzles or measure 1 nozzle and multiple by the amount of nozzles.]

So, using Bow & Arrow rate of 50 mL, we would then put 50 mL of Bow & Arrow Herbicide into 4.6 L of water and spray exactly like we just did on the concrete in terms of pressure, wanding pattern and walking speed and we will evenly spray 50 mL of Bow & Arrow Herbicide over 100 m2.

This is an example, please DO NOT simply take this as a dilution rate of 50 mL in 4.6 L of water. To get a result you need to calibrate, if you don’t your weed control will be limited and or overdosing can lead to turf damage.

If your calibration figure of water is over the water amount allowed, in this case for Bow & Arrow Herbicide over 5L of water per 100 m2, then you need to start again and do it quicker, an example of this would be if you measured a water volume of 680 mL per 10 m2 (which is 6.8 L per 100 m2) then you need to do it again quicker, applying a little less water to get to at least 5 L (or lower) of water per 100 m2 as per the prescribed water volume required on the Bow & Arrow Herbicide application directions .

If an end-user reads the Bow & Arrow label and says, “right the dilution rate / mixing rate is 50 mL in 5 L of water per 100 m2 – because that’s what it says!”, and they go physically apply 10 L of water (dilution) per 100 m2 then they will have actually applied Bow & Arrow at 2 times the rate per 100 m2 rate. This is when turf damage WILL occur. Furthermore, if they mix at a dilution rate they think is right based on Zero calibration they can also use too much water (leading to too much spray run off the weed foliage) and underdose which will lead to poor weed control.
If you are not getting a result or getting damage you are applying these products incorrectly. Turf Culture’s products require a ‘set rate’ over a ‘set area’ in a ‘specified amount of water’. YOU need to achieve and know the water volume within the specified amount of water by how you spray with YOUR spraying equipment. Water is your only carrier and vehicle to apply these products, without knowing the water volume YOU spray per 100 m2, YOU can never achieve a ‘product rate’ evenly over 100m2 (or your desired area).

Without calibrating your equipment when you spray an area you are almost guaranteed to be either over-dosing or under-dosing, you will never know. Hence without calibrating your equipment when spot spraying you are well and truly DOOMED.

By simply turning a sprayer on and off whilst NOT moving the nozzle (NOT wanding back and forth evenly over an area) gives overdosing and will guarantee turf DAMAGE. Spot spraying can only work after calibration.

First - Calibrate.

Second - Imagine each single weed (or small group of weeds) are in the middle of a 1 or 2 metre squared area, spray over that 1 or 2 metre squared area just as you did when calibrating on concrete.

© Copyright - Turf Culture

Turf Culture



Bow & Arrow Herbicide
Active Constituents:
20 g/L CLOPYRALID present as the potassium salt
300 g/L MCPA present as the potassium salt

For the Control of various Broadleaf Weeds in Turf such as White Clover, Plantain, Capeweed, Cat's Ear, Bindii (Jo-Jo, Onejunga), Cudweed and Creeping oxalis.
APVMA Approval No.: 64580
For more information: PRESS HERE