Oak Wilt in S/SE TX

[tstex]

I just diagnosed [and had confirmed by a TX Forestry Agent that visited my ranch] that I had 2-3 live oaks in different areas with Oak Wilt,  The leaves demonstrated the iron-clad sign of veinal necrosis; it is for sure Oak Wilt.  Also, in all three areas, there are many other lives oaks within the drip lines of the infected trees...some of these are 100-150 yrs+.  None of the neighboring trees have shown any signs of infection.  If any of you would be so kind to share what has worked and what has not, it would be greatly appreciated. 

My ranch is 60 miles WNW of Houston.  The soil is predominately sandy loam and is very gentle sloping.  Some of the infected tree's were pruned, but it was over 5 yrs ago with no signs of OW until just recently.  One of the trees just started dropping it's leaves about 2 months ago and I thought it was the back-end of stress from the TX drought.  It was not.  For pruning, I now only trim during winter and apply pruning spray.  Let me know if you have any questions regarding the current status or conditions.

Your help and feedback would be greatly appreciated.  I would like to start an action plan immediately.

Thank you very much, tstex

[Texas Ranger]

Did the forest service talk to you about root pruning?  One source of infection is transfer through root grafting.  It may help, but talk to them, or the extension service, for the details on how and if.

[tstex]

Did the forest service talk to you about root pruning?  One source of infection is transfer through root grafting.  It may help, but talk to them, or the extension service, for the details on how and if.

Yes, it is called "trenching", which severs the roots/boundaries from the alleged infected trees and quarantines the "infection site".  It would cost somewhere around 5-10K per site = 15K - 30K...this isolates the "infection site" and it would require getting my neighbor involved and he is "tight" !!! 

The TX Forestry Agent gave me 2-3 options, but I wanted to get some real-life experience from people that have done something with both a personal vested interest and their own personal financing as well.  Folks like this have "skin in the game" and know exactly what i am referring to here.  After my ultimate plan is implemented, and I experienced the time to see the results, you can bet your life I am going to post everything here.  I will provide as much info and assitance to you guys as possible...we have a real fight on our hands.

Thx,
tstex

[beenthere]

I decided against the trenching option, because of the expense. I use the option to only cut/trim/prune during the winter months. Other than that, the last option is to turn it into firewood when the oak trees die.

What are your 3 options?  Different from mine?

[tstex]

I decided against the trenching option, because of the expense. I use the option to only cut/trim/prune during the winter months. Other than that, the last option is to turn it into firewood when the oak trees die.

What are your 3 options?  Different from mine?

B-there,

Here are the three options:

1) trenching, which we all know is quite expensive
2) fungicide injections which is mainly preventative/proactive, not theraputic...lasts 18 - 24 mos and costs about $75.00 for a 91" worth of tree
3) do nothing, cut down dead trees one yr after they die.  they say to not cut anything while dying or within 12 mo's to prevent spreading of f-spores.

I consider cutting/pruning/etc purely a maintenance issue, but doing it at the right times prevents the beetle from spreading the above grd vector.  Once a tree or surrounding area has OW, I would refrain from cutting anything unless lightening or strong winds/ice breaks branches and you need to then properly trim them.

Regards,
tstex

[Texas Ranger]

Anyway you go, it is a crap shoot, the trenching seems really  high.  A farmer with a subsoiler would do just as good, for a lot less, most oak roots that graft are in the top 12" or so of soil.  There are a lot of fly by nighters that will "inject" a fungicide and show no results.  Source and insect control is about the limit at what you can do.

[tstex]

Tx Rngr,

You bring up some good points...

"A farmer with a subsoiler would do just as good, for a lot less, most oak roots that graft are in the top 12" or so of soil."

Can you expound on this where you have heard of some actual successes?  I would definitely like to investigate this if it is possible.  Also, where/if successful, what type of soil was present?  We have this sandy loam around here and when drilling end-fence posts, I have gone down 5' before even hitting clay...as a result, those feeder roots seem to go/grow much deeper than 12".  However, I would love to be wrong!

"There are a lot of fly by nighters that will "inject" a fungicide and show no results.  Source and insect control is about the limit at what you can do."

I am basing the injection option on what has been done and worked/not worked in this particular area.  Based on my initial discussions, performing the injections [by the landowner after seeing the process done]in the flare roots to spec has yielded pretty good results in a preventative mode right next to infected trees.  I am just trying to form a strategy that gives me he best bang for the buck with my labor being a prime resource.

I wish this was not a crap-shoot, but there are still many unknowns to date.

Thx,
tstex

[beenthere]

I think it is a crap-shoot, at best.

A ditch-witch may give you more depth and could be run around the oaks. Sever the root connections is all you are after. Prolly have to do it again in a couple years, but it may keep it from spreading from the trees infected now. At least, it seems the best hope to stop it from moving. Seems ditching would be the cheapest gamble with the best odds. IMO.

[Ron Scott]

Our most effective control of oak wilt here at present is trenching with a 5 foot vibrator plow. The trenching cost averaged $1.50/foot during 2009. A back hoe may be used in some cases, but it must go to a 5 foot depth.

The essential concept is to isolate the infection, remove above-ground trees, and let the disease die-out underground. The work is done in the fall, October. Following the plow treatment, overstory oak must be removed and properly disposed of.

[LeeB]

My personal observations from when we lived in cetral Texas where the oak wilt has hit hard, is that all you can do is slow it down for a few years. You will not beat it. The fungicide teatments do little to nothing. Trenching is only a short time and costly stop gap. We manageed to keep it back by doing no trimming at all. Every one around us had it for years before it finally hit us. It takes the older trees first and then the younger ones. Some come back out for a little while but usually succumb the next year or two. Live oak is hit expecially hard by it. I know this is not what you want to hear, but I don't give it much hope. Plaant something else now. Burr oak and most other white oaks are not very susceptable and burr is reasonably fast growing. Sorry for your loss. I know the pain.

[tstex]

My personal observations from when we lived in cetral Texas where the oak wilt has hit hard, is that all you can do is slow it down for a few years. You will not beat it. The fungicide teatments do little to nothing. Trenching is only a short time and costly stop gap. We manageed to keep it back by doing no trimming at all. Every one around us had it for years before it finally hit us. It takes the older trees first and then the younger ones. Some come back out for a little while but usually succumb the next year or two. Live oak is hit expecially hard by it. I know this is not what you want to hear, but I don't give it much hope. Plaant something else now. Burr oak and most other white oaks are not very susceptable and burr is reasonably fast growing. Sorry for your loss. I know the pain.

Lee B,

Where did you live in Central TX and what timeframes [yrs]?  Did you ever experience the tough droughts?

Next, what was the configuration of your trees that you lost [and the ones you did not]?  Meaning, did you lose the ones that were isolated from the roots of dying trees that were in access of 200ft?

What was your main soil type where most of your trees died?

My goal is to not save the world [too costly], but be selective in the ones that I can save or post-pone.  The State Forestry Service rep came to my place and said that about 5 - 15% of the trees that he observed did not die with or without treatment and all had dying/infected trees within their driplines.  He called them "pass through oaks".  He did not know why or how they were resistant to the pathogen, but they were...did you see any of this?

Thank you for your responses and your candidness...it is always better to hear what you need to hear than what you want to hear...enables appropriate planning and proper expectation setting...

Regards,
tstex

[LeeB]

We lived just north of Austin in Liberty Hill. We lived there for 20 yearsand most definately went through the draughts. The oak wilt was worse after the druaght. I suppose due to the  weakend state of the trees. Soil type was clay and caliche. We did no trimming of our trees at all and managed to hold out longer than the nieghboring places before the wilt hit us. It didn't hit any specific area, although it did come first from my adjacent nieghbor that had already lost the majority of her trees and even then it was not inthe drip line of her trees. We sold out and left before it got real bad so I 'm not sure how bad it became. It was jumping large spans before we left and was hitting older trees and younger trees leaving middle aged trees at that time. I haven't been back in 3 years, so I cannot tell you what happened since.