Fungicide resistance duration in a fungus population

[bovine421]

They advise in rotating fungicides and crops so my question is how long does a fungicide resistance last in a fungicide population. Is it just during that fungus life cycle or is it past generationally through the spores.
 Can the genetic cycle be broken?

[pagnr]

The resistance should be permanent. Since Fungi have a few stages in the life cycle, it might vary at the stages. Spores are the main problem, as they carry the resistance even when the Fungus isn't active or conditions not favourable for disease outbreaks and can be highly resistant to any treatments.
You can't break the resistance by the same treatment, only another fungicide type  or treatment ( heat, beneficial microbes, ) can reduce the resistant population.
If you can kill the Fungi with the alternative fungicide treatments or methods, you may get a clean slate for the original fungicide that was resisted.
You can only break the genetic resistance by killing those with another fungicide or method, and rotating against developing resistance to the fungicide.
Fungicides are usually in groups of related chemicals or mode of action. It is usual to rotate the groups, not just fungicides, to keep ahead of resistance problems.

[bovine421]

Thank you! You did an excellent job of answering the question. I find this subject fascinating and thankful my livelihoods doesn't depend on it. I understand after two applications of a Frac group you should  rotate. I find it interesting that some fungicides have two different Frac groups that have the same mode of action just different sites of action. Another interestingly scary fact is if you do not rotate or apply properly you will overtime increase the resistant fungus population. Another scary thought is even if you are a good steward with fungicide rotation and proper application but your neighbor is not. Those nasty spores can travel in the Wind.. Most of my mango trees have not bloomed yet and are fairly clean but to be prudent I sprayed for anthracnose. I will use sulfur on the bloom then rotate to another Frac group at fruit set. I've been asked not to discuss the subject of fungicides on social media for fear the General Public will miss use fungicides and increase the anthracous resistance in South Florida. From being on this forum I have a fairly substantial Arsenal to rotate with and follow the state of California guidelines for fungicide rotation

[pagnr]

Cheers.
It is also interesting that the situation is paralleled with herbicide resistance in weeds, and chemical resistant weeds strains are developing and spreading in some areas.
Rotation of herbicides is required or alternative technologies, such as heat, steam, mechanical removal / tillage or targeted herbicide application with a software based weed recognition camera and spot sprayer to reduce herbicide use.