Needle cast. Cure or ?????

[Mike Corazzi]

Here's a pic of one needle. Sylvestris....Scots
Not many are as extensively as browned as this one.
It did not pull out easily.
There are a lot of 1/8 to 1/3 brown tipped needles.

In CA, we can not get Cleary's 3336 antifungal.

Would an external spray be good to use? If so, would Benomyl be of any use?
Or something better?

And WHEN should I hit it with it if at all at this point?

Would it do any good (or harm) to clip the brown tips OFF of the existing affected needles?


It is raining steadily and no sun is predicted for quite a while.

This needle has flattened itself from middle to the end.

Lots of new unopened buds at this time.

 

[Paradox]

The problem with needle cast is that the needle is infected one year before the disease manifests itself. This is why people spray fungicide on their trees during the wet/high humidity periods of the spring/summer when trees are more prone to infection. I dont know what Benomyl is but I do use Daconil and a copper based fungicide on my trees in the spring and throughout the summer. You cant do anything about the current brown needles except start to remove them if they get very brown. I would start a fungicide program to help keep it from happening in the future. Follow the instructions on the bottle and you are going to have to wait until you get a few days of dry weather or it will just get washed off.

 

[Mike Corazzi]

Poking around google indicates that Benomyl is one that will treat needle cast.

https://books.google.com/books?id=y...IQzAI#v=onepage&q=benomyl needle cast&f=false

I can also try the Daconil .

 

[Leo in N E Illinois]

The fungicides won't do a thing to improve already infected and showing symptom needles. Its function is more as a preventative. Fungicides are effective, especially Daconil. and Cleary's 3336 which you can't get. Make sure the label on the fungicide includes needle cast as a target fungus. If it doesn't, then it might not have effect. Once you have needle cast anywhere in the collection, you need to treat all the conifers to proactively prevent the spread to other trees. You need to treat as recommended in spring and autumn, so that the fungicide is in the trees during the time periods when spores are floating in the air. Read local ag extension bulletins, because they can actually give you local dates for when the treatments are needed. Climate changes the timing for spore release from the needle cast fungi. On your California Ag Extension website, wander into the Landscape Nursery section, and search needle cast there. You may get county by county dates timing the use of fungicides. Needle cast is an economic significant pest to the landscape nurseries, likely some effort has been devoted to the topic by your local Ag Extension.

Paused my writing to do some web search - chlorothalonil is recommended for several species of fungi that cause needle cast in firs, pines, spruce & douglas firs. One trade name for chlorothalonil is Daconil.

Here is a link to UC Davis IPM site, mine it for info - http://www.ipm.ucdavis.edu/GENERAL/whatisipm.html

from Unv. Kentucky 2 pages sheet on identifying and when to treat 3 different fungi that cause needle cast. Daconil is listed for all 3, Benomyl is listed as only being effective on one of the 3 fungi. Timing of application is every 3 weeks in wet weather, Spring for 2 genera, July through October for 3rd genera. All say it is only necessary during moist weather. Putting the pine in a sunny, exposed situation where soil and needle surfaces dry quickly after watering or rain will go a long way to preventing infection. http://www2.ca.uky.edu/agc/pubs/id/id85/id85.pdf

another California orientated needle cast info sheet http://www.na.fs.fed.us/spfo/pubs/fidls/dothistroma/doth.htm

 

[Leo in N E Illinois]

several of the needle cast fungi have a 2 year life cycle. Once infected treatment should continue for at least 3 years, probably for two years after last symptoms were spotted or it will be a constant reoccurring problem. If it is present in the landscape, it may be a life long battle. Remember to alternate between at least 2 different mode of action fungicides, maybe 2 treatments with one, followed by one or two treatments with the other. Otherwise resistance may possibly develop.

One more link - http://caforestpestcouncil.org/wp-content/uploads/2008/06/Insect-and-Disease-Training-Manual.pdf

 

[Mike Corazzi]

This whole thread may have been premature. AND WRONG!
THIS year....after getting the thing out of the rotten kakadama and giving it plenty of fertilizer in LAVA (with a few other things)
it is greening up nicely and the buds are what I'd call PROLIFIC.
I am rapidly coming to the conclusion that what I ....thought... might be needle cast. was just the result of poor conditions.