Swiss Needlecast? Treatment?

[YoungBuzzer]

I've attached a picture of what I believe is Swiss Needlecast. Has discolored areas of the needle on top and the two parallel lines of black spores on the bottom. Do you all agree?

It is a grouping of 6 to 8 Douglas Firs, all planted close together, ranging in height from 15 to 25 feet tall. One tree has lost all of last years needles and two that have begun to lose last years needles. The rest look perfectly fine. From what I have read, the fungal infection is normally caused by close plantings with warm, humid and wet conditions - fits this years weather in SE PA.

Does anyone recommend treatment options? Foliar spray, type of product and how many treatments? Is it too late in the season to begin spraying?

I would appreciate any input you all may have!

Thank you,

Tyler

 

[RopeShield]

http://www.plantpath.cornell.edu/Trees/LophNcst.html
http://na.fs.fed.us/spfo/pubs/misc/red%20pine%20pocket%20guide/lopnc5.htm

Contact your local nurseryman/christmas tree grower to see what is working for them.

Cheers

 

[YoungBuzzer]

Thanks RopeShield, didn't think of the Christmas tree farms/nurseries. Will check that out.

Anyone else had any experience with treatment?!

-Tyler

 

[UrbanForester]

16 oz of Thiophanate Methyl 50 WSP and 22 oz of Chlorothalonil 720 SFT per 100 gals. 3 applications at about 3 week intervals starting in late April, early May (in Michigan)works very well.

 

[YoungBuzzer]

Thanks Urban,

So I assume it's best to just wait until next year to treat or should something be done this year to help it until next April?

Thanks for the info!

-Tyler

 

[UrbanForester]

Yep, 2014. The infection period is over. Keep the trees as healthy as possible by proper maintenance esp. if they've suffered any significant needle loss. No NPK though, more succulent new growth would just be a rich infection target area.

 

[Knowledgequest]

Two chemicals with different modes of action. Smart.
Spectro 90 comtains both, labelled for needlecasts. Might $ave a buck.