Prelim trials of Micro-infusion versus macro-infusion for prevention of OW

[Dbodave]

Hey Everybody,
I recently attended a tree health seminar and I am reporting on a talk by Jennifer Juzwik with the US forestry dept. The talk was mainly about the disease cycle of oak wilt but in the end she mentioned a trial she started in 2015 where they challenged micro-infusion injected oaks with the oak wilt fungus. Results are preliminary but the micro infusion treatments were proven equally effective as macro infusion.

Here is an outline of her speech she sent me when I requested more info:
Oral: Micro-infusion versus Macro-infusion of Propiconazole for Prevention of Oak Wilt Development in Oaks in Texas and Minnesota.

Don Grosman, Jennifer Juzwik, Jeff Palmer, William Upton

Oak wilt, caused by the vascular fungus Ceratocystis fagacearum, kills considerable numbers of live and red oaks across much of the north central and southern United States. In recent decades, disease development has been suppressed in trees in many locations for several years following macro-infusion of high volume dilutions of the fungicide propiconazole. Although effective, this application method often is very labor intensive and time consuming. We evaluated the efficiency and efficacy of micro-infusion of lower volume dilutions using the TREE IV™ (Arborjet Inc., Woburn, MA) compared to macro-infusion for preventing oak wilt development in live oaks inTexas and red oaks in Minnesota. The micro-infusion application was considerably easier and required less time to apply to oaks in Texas compared to macro-infusion, because the latter application required an air spade to expose primary tree root flares prior to injection. In contrast, an air spade was not used with the macro-infusion application to oaks in Minnesota. Thus, average application times in Minnesota were not significantly different for micro- and macro-infusion. Both application techniques were equally effective in reducing oak wilt symptom development and tree mortality in both locations compared to disease controls. These studies are ongoing and this talk presents preliminary data only.

 

[Jed1124]

We don't have Oak Wilt here, yet. From what I understand, in treating Elm with Macro, the propiconizole works into the new terminal growth produced each year, where as with micro, only current wood is protected. So for DED I can see why macro is better because the elm bark beetle will enter any crack in a branch it can find, generally at the tips or small crotches. Then you get the typical branch flag, working its way down the parent stem.
With Oak wilt, the fungal matting is around the trunk. The vector picks up spores, and then moves them on to another oak. But from what I know, it is based around trunk wood. Micro injection done on a every other year basis, protects the vascular system in and around the trunk wood, so the advantage of Macro that is seen in Elms is not apparent in the Oaks.
This is just a guess. I only use micro injection myself so it is good to hear.

 

[Dbodave]

I don't know of any trials studying micro with elms but I don't think there would be a difference. Label for micro infusion states 2 years protection I believe.
One difference with oaks is the treatment prevents root graft transmission. We mainly use the treatment when there is OW in the root graft vicinity of other red oaks.

 

[Yellowdog]

any follow up with this? I don't inject commercially but my family owns several ranches and I do inject there using TreeTech micros for oak wilt. I've been doing it for about 3 years. So far, my results for actual product delivery are mixed even though I take my time and do it EXACTLY as prescribed. Some units seem to not drain well while others, when removed prematurely and even though the nozzle broke the seal, do not allow the liquid to drain out. Other units will drain the 10ml as soon as you remove it from the tree (if it's not empty). That inconsistency has me frustrated and I may switch to Mauget and I am trying Chemjet. I have spent over $1000 on Tree Tech micros and some worked and some didn't. So far, I haven't lost any trees that were treated near an oak wilt center but this Spring, when conditions started to be right for uptake, I've had a disaster as far as uptake and this is near a new center where I cannot trench.

Anyone else have anything good to say about micro versus macro? Any pointers or brands to check out?

 

[Jed1124]

any follow up with this? I don't inject commercially but my family owns several ranches and I do inject there using TreeTech micros for oak wilt. I've been doing it for about 3 years. So far, my results for actual product delivery are mixed even though I take my time and do it EXACTLY as prescribed. Some units seem to not drain well while others, when removed prematurely and even though the nozzle broke the seal, do not allow the liquid to drain out. Other units will drain the 10ml as soon as you remove it from the tree (if it's not empty). That inconsistency has me frustrated and I may switch to Mauget and I am trying Chemjet. I have spent over $1000 on Tree Tech micros and some worked and some didn't. So far, I haven't lost any trees that were treated near an oak wilt center but this Spring, when conditions started to be right for uptake, I've had a disaster as far as uptake and this is near a new center where I cannot trench.

Anyone else have anything good to say about micro versus macro? Any pointers or brands to check out?

You would be best served by switching to ArborJet or Rainbows system using Alamo fungicide.
That being said I have used Tree Tech’s Snipper product and liked their capsules.
But with any volume an IV system would serve you better.

 

[Dbodave]

any follow up with this? I don't inject commercially but my family owns several ranches and I do inject there using TreeTech micros for oak wilt. I've been doing it for about 3 years. So far, my results for actual product delivery are mixed even though I take my time and do it EXACTLY as prescribed. Some units seem to not drain well while others, when removed prematurely and even though the nozzle broke the seal, do not allow the liquid to drain out. Other units will drain the 10ml as soon as you remove it from the tree (if it's not empty). That inconsistency has me frustrated and I may switch to Mauget and I am trying Chemjet. I have spent over $1000 on Tree Tech micros and some worked and some didn't. So far, I haven't lost any trees that were treated near an oak wilt center but this Spring, when conditions started to be right for uptake, I've had a disaster as far as uptake and this is near a new center where I cannot trench.

Anyone else have anything good to say about micro versus macro? Any pointers or brands to check out?

The arborjet system is really good, no leaks or anything, wounds are kept sealed with the arborplugs. It's expensive but really works well and a good healthy oak only takes about 30 min to treat. Of course when they are within root graft distance I double the rate and use 20ml propizol per 1" dbh.

I used the rainbow scientific macro system for years and it works but I don't think it works well and you might spend 2-4 hours on 1 tree.