My bit of Ninwells wood was largely populated with Corsican Pine when I bought it back in 2013. They looked a bit sickly but I put this down to the fact that they had not been thinned and were all competing with one another. I soon found out that they were suffering form Needle blight and after some research I decided the best thing to do was to fell the lot.
In Britain, Dothistroma Needle Blight (DNB), also known as Red Band Needle Blight, is caused by the fungus Dothistroma septosporum. It has been found on a range of conifer species, but pine (Pinus) are by far the most common hosts, with Corsican pine, lodgepole pine and Scots pine all now affected. Defoliation can continue year on year and gradually weaken the tree, significantly reducing timber yields. It can also eventually lead to mortality.
I was advised by an expert that as many as 30% of the trees could die in a 10 year period. I was also informed that despite an infection the timber was still saleable, so long as it had not actually died and that the most economic course of action was to fell it before too many actually died from the disease. That was what I did.
Next to my bit of woodland are two areas owned by other people and both have Corsican pine on them. In just 3 years these pines have massively deteriorated and many are now dead and falling over. It is said that opening up the woods and allowing more movement of air will reduce the activity of the fungus causing needle blight. However opening up the area has also made the trees more vulnerable to wind damage and as these trees are already weakened they have suffered quite extensively.
It is not my problem but, it would seem to me that the owners of these woods would be best advised to get them felled as soon as possible, whilst there is still some value in the timber and before too many get blown over, which will of course make the task of felling more laborious.
If anyone out there has Corsican Pine then I would advise getting it felled as soon as possible will reduce the damage from Dotristoma, and maximize your potential income from the trees. Then learn the lesson and replant with British native trees. Not that you will be guaranteed disease free with British but possibly stand more chance than if you plant some non native tree.