Visual stress grading of plantation hardwood

[mcsprint71]

HI all,
Did a hardwood visual stress-grading course a while back and seemed to remember that it only applies to forest logs rather than plantation but I can't find anything written about that. Can anyone advise?
Thanks
James

[John.G]

Visual stress grading is based on mature trees, rather then juvenile ones. I am aware that at least one species has been downgraded an F grade in recent times due to the increasing chance of the timber being sourced from plantation stock rather then mature trees.

I am unaware of any formal ruling regarding immature timber but that doesn't mean there aren't any ( I don't cut plantation timber so haven't needed to know).

[John.G]

Forgot to add that there was a fairly intensive trial of mid rotation E. pelliata done several years ago. The timber was very poor based on visual stress grading, however mechanical testing to failure revealed that despite the poor visual grading results it was in fact able to carry the equivalent MP grade quite easily. That may or may not carry over to other species.