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DX50 Chlorine Dioxide

Southwell Fungicide

Southwell Fungicide

Regular price $69.00 NZD
Regular price Sale price $69.00 NZD
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Improved fungicide

"Southwell Fungicide definitely works, no doubt about that. I have sprayed 50:1 for fireblight before the sun comes up or on cloudy days and the disease disappeared within few weeks"  Faizal Mohammed, fireblight treatment on apple trees, Auckland, Sep 2022.

With Southwell AC Broad-spectrum Fungicide, viticulture and horticulture have an advanced product that helps control both fungal and bacterial diseases of plants.

  • Ideal for small-scale home users 
  • No residue
  • An effective anti-bacterial, anti-fungal, anti-viral product
  • Highly selective oxidation
  • Not subject to bacterial or fungal resistance
  • Wide kill range (pH 2-11)
  • Highest EPA rating
  • No withholding period
  • Cuts through Biofilm

​How does Southwell AC work?

Southwell AC Fungicide is Chlorine Dioxide in an aqueous solution which kills by penetrating the cell wall of the target organism and disrupting its food supply. The triggering action for Southwell AC is the sugar-like substances that are an integral part of the target pathogen cell walls. Due to this mode of action, disease-bearing organisms cannot build up resistance to the product.   

Under certain conditions (heavy rain, high humidity, specific temperatures), disease multiplication can be very aggressive in susceptible host plants. Southwell AC kills rapidly on contact so early detection of disease should be followed by an application of Southwell AC Fungicide.

Winning the War

Fungal growths are easy to fight because they’re visually apparent. Bacterial diseases, however, are harder to combat because they are caused by an unseen, well-organised enemy. These concealed microbes spread disease by fooling plants into keeping their defences down. What makes fighting these pathogens even more difficult is their ability to develop a resistance to most chemicals. 

Except for Southwell AC Fungicide. Southwell AC controls both fungal and bacterial diseases and is not subject to bacterial or fungal resistance.




Apples, Pears

Fire Blight

5-10L per Ha (1:50/1:100)


Grey Mould (Botrytis)

5-10L per Ha (1:50/1:100)

Stone Fruit

Brown Rot

5-10L per Ha (1:50/1:100)

Kiwi Fruit


5-10L per Ha (1:50/1:100)


Alternaria Citri

5-10L per Ha (1:50/1:100)

Berry Fruit


5-10L per Ha (1:50/1:100)



20L per Ha (1:25)

Greenhouse Tomatoes


5-10L per Ha (1:50/1:100)

Fine Turf + Cotula

Fusarium Patch
Red Thread Brown
Dollar Spot
Leaf Blight

20L per Ha (1:25)

Flowers + Ornamentals

Botrytis Stemphylium Alternaria

5-10L per Ha (1:50/1:100)


"Great product. Cleared my lawn of red thread in 3 days . An amazing cost effective product. I have also sprayed my roses and scrubs and they all look to have marked improvement Happy to recommend this product" Noel Birchfield.


Please scroll down to see more reviews.

Shipping & Returns

We offer free delivery on all orders of Products over $150 shipped within New Zealand.

We offer a flat rate of $18 for shipping across New Zealand and $11 for 2Ltr container.

All orders are processed within 1-5 business days.

Please read our Return Policy


Store in cool, dry area.

Do not store above 30 C.

It is recommeneds that this product should not be exposed to light (especially UV light) as it will break down quicker.

Keep container tightly sealed when not in use.

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Customer Reviews

Based on 20 reviews
C J Brumby (Auckland, NZ)
Really Effective on Buxus

Used it on a buxus headge with blight. Sprayed soil surrounding as well. Really effective with new growth in earler dead patches. Good order process and delivered promptly..(The headge needs a cut I know)

Ross Ellis (Te Puke, NZ)

Don't need a handler's certificate for this. Helped dry up the botrytis in our flowers.

Grahame Johnston (Wellington, NZ)
No results so far

Prompt delivery. Easy to deal with. Sprayed my lawn for brown patch virus. Two weeks now and still spreading. Applied a second spray, waiting to see.

Merv Fair (Whangarei, NZ)

This product was completely new to me so l have held off making a comment until I had established how well it works. I am pleased to advise that it completely killed any existing botrytis and, to this point, has prevented a recurrence. Exceeds my expectations. Do you have a similar product that deals to blight?

Hi Merv,

We are delighted to hear about your success with Southwell Fungicide in treating botrytis. It's important to highlight that Southwell fungicide is most effective when used preventatively, so be sure to apply it before the issue resurfaces.

Regarding your question, Southwell Fungicide is also effective in addressing fire blight.

Cameron Burns

Very good results

Leslie Thompson
Need more time to give an honest review

It’s only been two sprays so far need longer to give an honest assessment

Noel Birchfield (Christchurch, NZ)
Dx50 fungicide

Great product. Cleared my lawn of red thread in 3 days . An amazing cost effective product. I have also sprayed my roses and scrubs and they all look to have marked improvement Happy to recommend this product

Rafe Hammett (Auckland, NZ)

Didn’t stop the fungus growing

Steve Woodward (Wellington, NZ)

Service and delivery excellent. I have sprayed fruit trees and roses once but it is a little early to see any results yet. Also I am not sure how often I need to spray or when is the right time to spray. I purchased this product to eradicate brown rot and leaf curl mainly in stone fruit. I would really appreciate some guidance on this if possible.

Stevo Devo (Auckland, NZ)
Southwell AC Broad-spectrum Fungicide

I sought out and purchased this product due to our lawn suffering from ‘Red Thread’ & Brown Spot’ fungus, probably due to our warm and wet summer.

The small (200ml) and expensive ($25) products available at the garden centres did not appeal, as I wanted to be able to treat regularly as required. I scarified our lawn and sprayed using this fungicide; it certainly looks like it’s doing the job for me so I’m more than happy with the results. A very effective and economical (5Ltrs. $79.35) solution to a common problem in Canterbury.