Disinfectants

Posted on by Better Bananas

Disinfectants prove to be an integral part of on-farm biosecurity

Using disinfectants as part of your cleaning regime is vital to minimise the spread of Panama disease. Research shows that various disinfectant products are effective in killing fungal spores that cause Panama disease.

Products listed in the table below are examples of disinfectant products which were shown to be effective when applied at 1% solution. 

 
Disinfectants used in vehicle dip for low risk vehicles.
Example of disinfectant products registered to control Panama disease in bananas

Remember...

Before using any chemicals always check the current registration status and read the product label.  A minor use permit is available for banana growers to use these products off-label (PER 86485) http://permits.apvma.gov.au/PER86485.pdf. Label and permit details can be accessed via APVMA website: www.apvma.gov.au

It is important to note that soil reduces the effectiveness of disinfectants. Different soil types have varying impacts on the effectiveness of the products. However, research has shown that once the equivalent of 1g of soil is present in 20mL of solution (1% product) then the effectiveness of products is compromised or reduced. 

Investigations into DDAC products (e.g. Steri-maX®, Path-X™, Sporekill® made at 1% solution) has found that when there is no soil contamination, these products remain effective as a disinfectant after being exposed to sunlight, temperature and humidity for up to 12 months. 

Quaternary ammonium compound test strips have shown to be an effective tool that measures the concentration of the active ingredient DDAC or BZK in disinfectant products. These easy-to-use test strips do not require dilution of the sample and are used by comparing the colour development on the test strip to the colour scale.

In summary:

  • DDAC and BZK disinfectant products used at the correct concentration and as per label or permit specifications (contact times) do kill the fungal spores that cause Panama disease. 
  • It is important to remove all soil and organic matter before applying any disinfectant product and replace solutions if they become contaminated.
  • Easy-to-use test strips can be used to regularly test solutions in footbaths, spray shuttles and wash-down facilities.

More info...

Remember: Always follow and adhere to product label rates and instructions. Label and permit details can be accessed via APVMA website: www.apvma.gov.au 

This research was funded as part of project BA14013 Fusarium wilt Tropical Race 4 – Biosecurity and sustainable practices which was funded by Hort Innovation, using the Banana research and development levy, co-investment from the Queensland Department of Agriculture and Fisheries and contributions from the Australian Government. Hort Innovation is the grower-owned not-for-profit research and development corporation for Australian Horticulture.

How can I test my QA disinfecting products?

Posted on by Better Bananas

Test strips can help determine the effectiveness of your disinfecting solution

Disinfectant products that contain the active ingredient didecyl dimethyl ammonium chloride (DDAC – e.g. Sporekill®, Steri-max® and Path-X™) or benzalkonium chloride (BZK – e.g. Bactex, Agriquat) have shown to kill fungal spores that cause Panama disease. 

For these products to be effective, it is important they are mixed at a 1% solution. Our researchers have investigated a range of test strips to measure the concentration of the active ingredient of disinfectant products used in footbaths, spray shuttles and drive-through dips.  

High level (0 – 1500ppm) or extra high level (0 – 10,000ppm) quaternary ammonium compound test strips are an easy method of testing the active ingredient DDAC or BZK by comparing the colour development on the test strip to a colour scale.

For your information...

1% solution of 120g/L DDAC (e.g. Steri-max®) equates to 1200ppm
1% solution of 100g/L BZK (e.g. Bactex) equates to 1000ppm
1% of solution of 250g/L BZK (e.g. Agriquat) equates to 2500ppm *

*(either dilute and use high level test strips or use extra high level (0 – 10 000ppm) test strips)

For best results, make up a 1% standard solution of the DDAC or BZK disinfectant product you are using. This will allow you to directly compare the exact colour of a 1% solution to the colour of the disinfectant sample you want to test.

Keep this solution in a sealed container for future use.

It is recommended...

It’s recommended that you dip your test strip into the 1% standard solution and the disinfectant sample (e.g. footbath) simultaneously, that way you can compare colour instantly.

1. Dip

Dip test strips into the 1% standard solution and your disinfectant sample and remove immediately.

2. Compare

Immediately compare test strip to colour scale (maximum reading time of 5 seconds).

The colour of your disinfectant sample should be ≥ the 1% standard solution (as per image above with green tick).

In summary:

  • Use test strips to regularly check the disinfectant solutions in your footbaths, spray shuttles and wash-down facilities to ensure they are at an effective concentration (1% solution).
  • Ensure there is less than 5% soil in footbaths and wash-down facilities – that is equivalent to 1g of soil to 20mL of disinfectant solution (1% DDAC or BZK product).
  • Be aware that soil with a high clay content may have the potential to influence test strip results.
  • Different water sources do not appear to influence the test strip results.
  • With no soil present in your disinfecting solution, DDAC products prepared to a 1% solution are still effective at managing spores that cause Panama disease. 

For more information about this work or for details on where to purchase the test strips contact the better bananas team –betterbananas@daf.qld.gov.au or 13 25 23 

Please note...

There may be factors beyond the scope of the research that has been undertaken using the quaternary ammonium compound test strips which have the potential to influence results. 

This trial was funded as part of project BA14013 Fusarium wilt Tropical Race 4 – Biosecurity and sustainable practices which was funded by Hort Innovation, using the Banana research and development levy, co-investment from the Queensland Department of Agriculture and Fisheries and contributions from the Australian Government. Hort Innovation is the grower-owned not-for-profit research and development corporation for Australian Horticulture.

Are cleaning and disinfectant products corrosive?

Posted on by Better Bananas

Are cleaning and disinfectant products corrosive?

Infrastructure such as footbaths and wash-down facilities are important components of effective on-farm biosecurity. Demonstration trials have been conducted to investigate the potential corrosive ability of various cleaning and disinfectant products on different metal surfaces.

Two demonstration trials were conducted and the same treatments were used in both.  Products included a detergent (Farmcleanse (10%), three quaternary ammonium products made to a 1% solution (Sporekill®, Steri-max® and Path-X™), and water as a control. Both trials demonstrated the effects of the above products on five different metals; unpainted steel, painted steel, galvanised, aluminium and stainless steel (grade 304).

The first experiment consisted of the metals being completely submerged in solution for 8 weeks, whilst in the second experiment the metals were treated by being dipped in the solutions frequently (2-3 times a week) then exposed to field conditions (temperature and humidity) for a total of 12 weeks. 

Metals submerged in solution.
Metals being dipped.

Outcomes of this research

The demonstration trials showed that the detergent and disinfectant products caused low levels of surface rust development over the 8-12 week period for the majority of metals. Unpainted steel was the most susceptible to surface rust development, while galvanised steel, aluminium and stainless steel were the least susceptible.

When submerged in solution, the detergent and disinfectant products did not corrode the metals significantly more than water alone. The water treatment appeared to have similar corrosive abilities as the other products trialled in this experiment. 

When dipped frequently and exposed to field conditions, all three QA products appeared to be more corrosive on unpainted steel compared to the water and detergent treatments. Furthermore, the QA’s had shown to be more corrosive on unpainted steel when dipped frequently as opposed to the submerged in solution application method.

Remember...

Always follow label directions for cleaning and disinfectant products. After the appropriate exposure time you can rinse metal surfaces with clean water to minimise the risk of rusting. 

What did the corrosion demonstration trial show?

Unpainted steel

Submerged in solution
  • Water appeared to have similar corrosive abilities as the disinfectant and QA products.

Dipped frequently

  • The QA products appeared to be more corrosive than the detergent and water treatments with frequent dipping application.

Painted steel

Submerged in solution
  • The paint bubbled and peeled across most treatments, with water only having the least amount of damage to the paint.
  • Rust development was present on the cut edges for all treatments.

Dipped frequently

  • The paint remained in good condition for all treatments.
  • Minor rust development was present where there were chips in the paint.
  • Rust development was present on the cut edges for all treatments. 

Stainless steel (grade 304)

Submerged in solution
  • The stainless steel remained in good condition for the duration of the experiment against all treatments.
  • Rust development was present on the cut edges of most treatments with the detergent having the least amount of rust visible.

Dipped frequently

  • None of the treatments appeared to degrade the stainless steel for the duration of the experiment.
  • Rust was present on the cut edges of the stainless steel on most treatments but with the detergent treatment having the least amount of rust development.

Aluminium

Submerged in solution
  • All treatments oxidised the aluminium with the exception of Steri-max®. 
  • The oxidised aluminium plates changed colour and developed a chalky texture across the surface. 

Dipped frequently

  • The aluminium remained in good condition for the duration of the experiment across all treatments.

Galvanised steel

Submerged in solution
  • A white precipitate developed on the surface of the galvanised steel plates on most treatments, except the detergent.
  • Rust developed on the cut edges of the galvanised steel plates treated with water.

Dipped frequently

  • The galvanised steel remained in good condition for the duration of the experiment and across all treatments.

For more information about this work contact the better bananas team – betterbananas@daf.qld.gov.au or 13 25 23

This trial was funded as part of the Fusarium Wilt Tropical Race 4 – Biosecurity and Sustainable Practices project (BA14013). This project was funded by Hort Innovation using the banana research and development levy, co-investment from the from the Queensland Department of Agriculture and Fisheries and contributions from the Australian Government. Hort Innovation is the grower-owned, not-for-profit research and development corporation for Australian horticulture.

How long are disinfectant products effective for?

Posted on by Better Bananas

How long are disinfectant products effective for?

Quaternary ammonium (QA) products have been shown to kill fungal spores that cause Panama disease. Our researchers have been investigating the longevity of three QA products that contain 120g/L of the active ingredient, didecyl dimethyl ammonium chloride. The QA products evaluated included Sporekill®, Steri-max® and Path-X™, at a 1% (1200ppm) solution.

So what did we do?

The QA products were placed in plastic storage containers outside (with the lids kept on) and exposed to field conditions (e.g. sunlight and temperature) for a period of 12 months. The high level (0-1500ppm) QA test strips were used as indicators to test the solutions on a regular basis, and at 4, 8 and 12 months intervals.  At these intervals, small samples of the solutions were collected and inoculated with fungal spores of Panama disease race 1.

QA disinfectant samples placed outdoors and exposed to field conditions.
Testing of QA disinfectants.

So what was the outcome?

The results showed that after 12 months exposure to sunlight, temperature and humidity, all three QA products were still effective at killing spores that cause Panama disease race 1. Testing at 12 months indicated a reduction in the concentration (using the test strips) for some of the QA products, particularly Path-X™. Despite the potential reduction, no colony growth was detected when samples of the three QA products were inoculated with spores of Panama disease race 1 in the lab. This result indicated that the products were stable, even after 12 months exposure to field conditions.

Test strips used to test concentration of disinfectants 12 months after exposure to outdoor conditions.
Image on left shows growth of 800+ fungal colonies recovered from control (water no disinfectant). No fungal growth was recovered from disinfectant solutions (image on right).

Good news for growers...

QA disinfectants used in infrastructure such as spray shuttles, that isn’t contaminated with soil and organic matter, will be effective for an extended period of time even when exposed to field conditions. However, always remember to schedule regular testing of your disinfectant solutions to ensure they are effective. This can be achieved by using easy-to-use test strips.

For more information about this work contact the better bananas team: betterbananas@daf.qld.gov.au or 13 25 23

This research is part of the Fusarium Wilt Tropical Race 4 – Biosecurity and Sustainable Practices project (BA14013). This project is funded by Hort Innovation, using the banana research and development levy, co-investment from the Queensland Department of Agriculture and Fisheries and contributions from the Australian Government. Hort Innovation is the grower-owned, not-for-profit research and development corporation for Australian horticulture.