Garsi

The issue with soil drench revolves around the introduction of pesticides into the wider environment, with the likelihood of adverse effects upon soil micro/macro fauna, many of which are essential for overall environmental health. The wounding caused by stem injection is certainly an issue, but probably a lower overall risk than soil or canopy drenching. This could maybe be complimented with the application of salicylic acid to boost the tree's vigour and response mechanisms? This is just a thought thrown into the mixer!

I was informed of this in Tree Pathology lectures in the early 90's, and have had plenty of time and opportunity to check this out 'in the field' since. As you said yourself, what I've seen backs this theory up, so I've no reason to doubt it as fact. Nothing is ever quite 'black and white' in nature though, but thats the beauty of diversity

The Scolytus beetle feeds on 2nd year bark, usually (but not exclusively) high in the canopy. The seemingly coincidental introduction of the Ophiostoma fungus renders the phloem of the host tree perfectly suitable for the beetle to breed for 2-3 years afterwards. This could possibly be described as a symbiosis? which would suggest evolution in action. Fresh, leafy growth and wounding undoubtedly attract the beetles, but a major point would be that the flight muscles of the beetle can only function if the ambient temp is at 72F or above, so pruning would be best carried out after August in most areas, maybe later in the south. As for resistance, nature tends not to wipe species out, so natural resistance in a small number of trees is likely, as is the case of Ash with Chalera. It also seems likely that the Scolytus beetle prefers to feed on English elm over Wych, so again this is likely in relation to other species/hybrids. Sterilisation of equipment is also an excellent idea, and not just with DED. Dettox spray seems to work well, so does alcohol-based sanitiser and neither will be toxic to trees.

I'm with you on this one, am a newbie on the forum but have comfortably managed every tree thrown at me in a 20 year career with a self-tied prussik loop. Looking at these setups, I would suggest I've also saved myself a fortune.........