Sanitatation pruning helps to keep it in check and removal of individual trees that have past the point of no return also helps.
I have a client that has several mature Austrian Pines on the property they own. These trees are very large and tall compared to the average Austian Pines in our area. Sixty footers with the broad wide spreading crowns. They are the focal point of the landscape.
We have been working on this property for over 10 years now. We took out three trees when we started. The rest we have been removing dead limbs and diseased tips from the on the rest of the trees . Intense climbing and nit picky pruning but it seems to have paid off. The disease is still present but has slowed down to the point that we have not lost any more trees until this fall where we had to remove one. The Pine we recently took down had decay in the root collar which was to me was a big factor,in it's demise, plus the stress of the Diplodia disease and then throw in the factor that our area is been short of rainfall since last year and a hot dry summer probaly didn't help.
There are probaly injections available for Diplodia, from my reading on the subject they are not that effective.
I have to go along with the general consenus that so many non native species are introduced that as these trees mature the site just is not condusive to supply the needs of the mature tree which leads to their decline. Making adjustments and amendments to the site may help keep the disease in check but it won't be a solution to the problem.
Great post, Axmeister.
The only diplodia I was taught about is Pine Tip Diplodia, & yeah it's a pretty generalized description for, "Something is wrong." True to its name, though... interior needle drop is usually a healthy & natural occurance (even when a customer insists the tree has never done that before ? LOL), while tips browning out is a sign of a problem. Like Ax said, non-native species, mature trees, hot / dry summer all contribute.
Sanitation clean-up (get rid of diseased trees / limbs) & a picky pruning (pun, har !).
Diplodia seems to take out entire sections, kinda like how blight spreads, rather that affect the entire tree at once & slowly decline.
I have had success with deepr root ferts (myco, kelp extracts, micronutrients) for slowing down decline.
Not sure off hand what caused the decay in root collar, it did progress up into the main stem about four feet. I'll see if I can find out what caused it. I have some older texts by Pirone and Carter. I remember reading a paragraph or two about decay in evergreens. The only other evergreen I can rember having decay in the stem was a Spruce, it was a Norway if I remember right, that one was a very long time ago. The other trees do show a normal flare.
Going to be a busy week this week with turkey day so I'll try to see what I can dig up for you Guy. If I don't reply soon don't think that I have forgotten you. Mrs. Ax has some post Thanksgiving activities planned, getting the outside of the house decked out for Christmas and that means stringing icicle lights among other things. She has a fear of heights and ladders, this is where I come in:roll:
I treated a property that had 3 austrian pines for 3 years or so.one of the pines had diplodia and fo all the money they spent to have me treat it we could have removed it and replanted with something else. the tree was still alive three years later when i left that company, and it looked better, but it was far from cured.
I tried mancozeb or dithane regularly. i did soil tests once a year and adjust the soil appropriately. i applied mycorrhizae once a year. i dug out the root collar and prune some girdling roots. I removed diebak and dead. i think i tried paclobutrazol ( as cambistat) on it as well to try and strengthen the roots. All that and it still had some signs of the diplodia when I left. the tree is in a gated community so I cant just drive by and look at it too see if it is still there.