Fungicide prophylactic useage

[Aeast]

Label is the law, so go off what the label says. You can look up any label online and see what its used for. Although dilution rates can get a little tricky to figure out in small doses.
Most fungus are fairly easy to control when using the proper fungicide and the proper timing. Most applications last about 10-14 days depending on the amount of rainfall, or if you water the foliage, then the application frequency increases. (Non ionic surfactants mixed in are usually a good idea). Protectant (barrier) fungicides need to be sprayed as new leaves/needles emerge to protect them until they "harden off". New fleshy leaves/needles are susceptible to infection, so there is no need to spray once they are fully grown because they are no longer susceptible. Even though some infections show up later in the year, they manifest when the leaves are first emerging.
Systemic fungicides have no real scientific data to back them up although they are used all the time for certain applications and some people swear by them. Systemic insecticides on the other hand are a different ball game all together.

 

[Aeast]

Some fungicides I use in my line of work are as follows:
Needlecast - chlorothalonil, copper hydroxide
Scab, rust - propiconazole
Anthracnose - Myclobutanil

Some of these are listed for the others as well.

 

[Aeast]

Apple on the left was sprayed for scab, the apple on the right was not.

 

[bonhe]

This is really hot topic and concern in medical community at this moment: Candida auris !
https://www.google.com/amp/s/www.nbcnews.com/news/amp/ncna992586
The scientists found out one of the reasons is that overuse of fungicides and insecticides in agriculture!!!
So, please careful in using them.
Thụ Thoại

 

[Aeast]

Kind of confused how one links fungicides and insecticides with a superbug in hospitals that attacks the sick of the sick? Superbugs are the result of individuals not taking antibiotics to the end of the cycle and the result is resistant strains.

 

[KLSbonsai]

@Aeast just curious to why you say there is no scientific data to back up systemic fungicides. The terminology of systemic has to had it reacts with in the plants system. A protectant only works by trying to stop the fungi from entering the plant. A systemic, depending on the mode of actions, will move locally from cell to cell or move into the vascular system and again depending on the fungicide and mode, move up through through the plant and in some case down into the root system. I use a rotation of modes of action fungicides for my job. I'm in georgia and manage the turf and plant health care on over 100 multi million dollar estates. Our customers prefer fescue turf which is transitional here at best. And of course they expect of everything to look perfect all the time. Makes work life interesting and stressful. As we all know when the conversation turns to chemicals and fertilizer opinions can hardlined.

 

[Aeast]

I guess I should have specified my comment to trees as to that is what I was referring, I didn't mean to make that broad of a statement and have no experience at all with turf grass. I have talked to some of the top plant pathologists in our state and that is their conclusion on systemic fungicides. But then again they are not the applicators and dont see the results.

 

[KLSbonsai]

In my experience we have used a product called SysStar to treat cryptomeria with twig blight and cercospora. We will usually root drench or inject into the root zone. With the rain we had last if was a must last fall for every cryptomeria we have. SysyStar is a combo of two systemics, thiophanate methyl and myclobutanil. Expensive combo but effective.

 

[KLSbonsai]

By all means, dont take my asking to being argumentative. I am always trying to learn from others experience. I am always experimenting and trying new products and techniques on both my bonsai and the trees at work.

 

[Aeast]

Same here, I wish systemics worked exclusively, the less spray the better. My main problems are; needle cast/blights, scab, fireblight, borers, EAB, galls, and the biggest pests of all... humans