Norfolk pine borer??

camm

Hi, I was hoping somebody might be able to help with some treatment advice for a borer problem I have in some norfolk pines. I have 7 norfolks all about 8-10m tall, 3 of these are starting to yellow from the lower branches upwards and starting from the trunk outwards, they also have signs of what i think could only be borer activity on the trunk. I have attached some photos to show this clearly. Any help would be much appreciated

Thanks

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derwoodii

Can't quite see borer at work here & not seen much borer on Norfolk's before either. Perhaps the cause is something else consider hmm off target herbicide eg broad leaf weed spray or a rust fungus. Can you get a neater pic of the suspect bore holes for us to be sure.

A few Q
is ground wet poor draining, have you sprayed nearby here are these newly transplanted stock Hmm even a fert deficiency .

Eric Frei

Yeah, look like they are on a golf course or something.

Also see this pic:-



The resin usually drowns out a borer, that's why borers tend to attack stressed trees, less resin/sap to drown them.

But I see small orange pin head things, could be frass from a borer, not sure.

I think though that there's more going on here. If it is a golf coarse they spray stuff like MCPP, Dicamba etc, can knock trees around.

Get a bit of wire and check those holes/resin spots. Coat hanger wire is perfect, sometimes you poke in there and you skewer the borer and can get it out, have a good look.

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camm

Thanks Guys, the trees are in a large grass area near some macadamia trees (not on a golf course), they were ex ground trees transplanted about 6 years ago, so are well established now. originally I thought the issue may have been too much water considering our weather conditions over the last 8 months in northern nsw, combined with some nutrient deficiencies, but then I noticed the white sap and red shavings over the trunk mainly on the yellower trees, It is very hard to make out any holes at these spots but seeing the sap I assumed a borer.?? some roundup has been used around the base sprayed by knapsack but not excessively.
Thanks for your help