In recent years there has been an increase in the market of Australian turf combination fungicides. With the launch of Clean Sweep Trio from Indigo Specialty we think it is time to put some information together on fungicide combination products. Combination fungicide products are also known as multi-site fungicides. They are formulated to include more than a single active ingredient and offer a number of benefits over straight fungicides but the key ones are:
- An increased spectrum of disease control;
- Completely new fungicide active ingredients for the Australian turf market;
- Longevities of up to 28 days after application;
- Convenience of handling one product rather than up to 4;
- A reduced likelihood of disease resistance occurring and finally
- Some of these can be legally used by home lawn owners.
An increased spectrum of disease control using turf combination fungicides.
One of their key advantages is to increase the efficacy of the fungicide treatment. To put it simply two or more active ingredients are more likely to kill the target pathogen than if applied individually.
Once a fungicide is applied to turf, it is subjected to a number of forces that work to remove or degrade the active ingredient. Only a small amount of the fungicide is removed by rainfall/irrigation and mowing. Most is degraded by a bulging community of naturally occuring soil microorganisms that also inhabit thatch and the leaf surface. Microbes rapidly attack substances like pesticides and break them down into products useful for their own nutrition and growth. Also, pesticides that work by penetrating the leaf surface (aka systemics) aren’t safe from attack as turf plants respond to pesticide applications within their tissue by dispatching enzymes that transfigure and detoxify alien substances.
Completely new fungicide active ingredients for the Australian turf market.
Both Indigo Clean Sweep Trio and Enclave (Adama) contain thiophanate-methyl. This is a new active in turf disease control whilst delivering strong eradicant, curative & preventative performance. Thiophanate-methyl is a member of the benzimidazole
group of fungicides being absorbed by the roots and leaves of turf. Thiophanate-methyl is a tubulin inhibitor fungicide falling into the FRAC Group 1. Its Mode of Action is the inhibition of microtubule assembly. Presentation on Clean Sweep Trio.
Longevities of up to 28 days after application using Turf combination fungicides.
All of these products give from 14-28 days control against a wide range of turf diseases.
Convenience of handling one product rather than up to 4.
By treating potentially several diseases at once, these solutions reduce application time. Since prepackaged goods are both physically and chemically compatible, they also reduce some of the uncertainty related to fungicide compatibility.
A reduced likelihood of disease resistance occurring
Since each pre-mix is a combination of at least two groups, you might be able to reduce the need to rotate between mode-of-action groups.
Using a pre-mix gives you the peace of mind that the fungicides are chemically compatible with one another. In fact the active ingredients can all sometimes be useful against the same disease. As a point of note, a pre-mix cannot control resistance if it’s range of activity does not overlap.
The majority of pre-mixes seem to have been developed in order to increase the spectrum of activity of a single fungicide. But what about DIY mixtures? Yes, creating your own mixtures may be useful in managing resistance, but you can risk causing phytotoxicity. Also in the case of thiophanae-methyl this is only available with a turf registration in combination products.
Both selection pressure and mutation contribute to the rise in resistance. Combining fungicides will reduce the amount of time that each active ingredient is exposed to the environment. This in turn limits the selection pressure on pathogen strains that are resistant to each particular fungicide.
The use of combination products offers an excellent resistance management strategy where resistance risk is high such as anthracnose, dollar spot, and fusarium sp).
Furthermore, this improved efficacy can lessen the chance of resistant mutation occuring even with these lower fungicide doses. There is plenty of evidence that fungus cells can change when under stress. Sublethal doses cause a degree of stress that can cause a variety of alterations, such as fungicide insensitivity mutations. The frequency of mutations will decrease if combining fungicides makes these sublethal doses more lethal.