water quality can have a big impact on herbicide performance. In fact poor quality water can cause some herbicides to fail completely resulting in a waste of time and money. Water quality issues such as water pH, turbidity, and whether it is hard water can all result in poor performance. Simply using a spray tank buffer like Manta Ray with glyphosate can lead to significantly improved results with your spray programme.

1. 2023 How water quality effects
herbicide results

2. ● Water is the used as the main carrier When you
make herbicide applications water is the main
carrier that you use.
● Spray solutions commonly contain 95% or more
water
● How a herbicide behaves in a tank mix is a result of
the water and herbicide chemistry

3. Factors that can effect how well a herbicide will work
include:
● Water pH
● Hardness
● Alkalinity
● and turbidity.
Water pH is the concentration of H+ ions.
The amount of calcium, magnesium, sodium and iron
will give you water hardness.

5. ● Hardness is expressed as an equivalent of calcium
carbonate.
● Turbidity is caused by suspended solids, soils, or
organic matter
● Alkalinity refers to carbonate and bicarbonate levels
in water
● An irrigation suitability analysis should have this
information

6. Below are the common ions found in water but other
ions can also have an effect
Cations (+ charge). Anions -
charge
■ Calcium. Sulphate
■ Magnesium. Chloride
■ Sodium.
Bicarbonate
Carbonate

7. ● Dirty spray water can deactivate herbicides with
high Koc values
● Clean water is very important for these herbicides
● Herbicides with low Koc values are not affected

8. Sulfonylurea herbicides

9. The solubility of sulfonylurea herbicides (Destiny,
Duke, Tribute, Monument increases with higher pH
● The amount of dissociation depends on the pH of
the water
● Dissociated herbicide molecules have a negative
charge
● Herbicides with high Koc values are sensitive to
turbid water

10. Glyphosate

11. ● Glyphosate has a high Koc and is greatly affected
by turbidity. Effects can be reduced by
● Using higher rates
● Adding sulphate of ammonia to the spray solution
or adding a spray buffer like Manta Ray
● Using the spray immediately after mixing
● Using low volume sprays.

13. ● Common to get poor results
● Poor Water quality often the reason
● Hardness higher than 350 mg/L can affect low rates
and over 700mg/L can affect high rates

14. Tank mixing sequence for spray
buffer

15. 1 2 3
Half fill spray
tank with water
and commence
agitation
4
Add the appropriate amount of
Manta Ray Buffer.
5
Add the appropriate
amount of herbicide,
fungicide or foliar fertilizer
Continue agitation
Top up with water