We use macro-infusion for our injection process. High value trees within 100 feet of an infected tree should be injected. It is a labor intensive process and can range from 9-15 dollars per diameter inch. There are no guarantees it will work, but it is one tool that has had success and it can increase your trees chances for survival. Keep in mind that if you do not inject a tree located in an area with high disease pressure, it will most likely die.
Macro-infusion allows us to administer a large volume of fungicide solution under a low pressure system. To start the process we expose the flare roots ( or buttress roots) of the tree. This insures the fungicide is evenly distributed throughout the tree. Tip: Make sure the company you hire to treat your tree exposes the flare roots carefully and diligently.
The tree is then measured at diameter breast height (DBH, which is 4.5 feet about ground level). This is needed to determine the proper amount of fungicide and water to treat the tree. After the dosing is calculating the solution is mixed and pressurized into a sealed container and the harness ( a series of plastic injector tees and poly hose) is assembled. A rule of thumb is 1.5 injection sites per diameter inch….so a 10-inch tree typically has at least 15 injection sites.
After the tank is complete and the harness is assembled the tree is ready to be injected. We use a SHARP high helix drill bit to drill holes into the flare roots. The holes are evenly spaced out avoiding the canyons between the flare roots. The system is then opened the air is removed from the system and the tree immediately starts taking up the fungicide (in most cases).
FACTORS THAT INFLUENCE INJECTIONS
Injection of high value trees can be very successful if applied properly and in a TIMELY (see more about timing below) fashion. Below is a list of some the factors that play a role in the success of oak wilt injections (not in any particular order, but they all have a very important role in the process)
- Technique
- Timing
- Environmental conditions
- Distance to oak wilt infected tree
- Type of injection
- Fungicide used
TECHNIQUE:
What do I mean by technique? Just like any other trade there are skills that you development from trial and error along the way….injecting trees is no different. Examples: How long you spin the drill bit to drill the hole for the injection tee, How sharp is the drill bit, Proper placement of the injection tee, and proper spacing of injection tees. There are many do’s and dont’s that make the process more effective as well as speed up the process.
TIMING:
Timing can be interpreted two different ways at it relates to the process. First, what is the timing on injecting a tree for oak wilt? Our best success comes when the tree is treated 40-100 feet away from an infected tree. We have on occasion treated infected trees and saved them, but this is RARE. Treating to soon will not protect the tree.
Timing in regards to when the treatment should be done. Injections can be performed from April-February (depending upon weather and individual trees these times may vary). Injections can not be successfully administered during leaf drop (which on our live oaks is in the spring). Once oak wilt is identified the trees that are candidates for treatment should be treated as soon as possible…2 or 3 weeks can make the difference in saving your tree.
ENVIRONMENTAL CONDITIONS:
Temperature, Wind, Moisture, etc…play very crucial roles in the injection process. Temperature, if the temperature gets to hot (over 95 degrees) the stomata in the leaves close and this stops the transpirational pull of water up the tree. Without movement of water the tree will not take up the fungicide solution. Wind, if it is too windy and the tree is loosing excessive water thru transpriation the stomata in the leaves will close. If the soil around the tree is too dry, it will slow the intake of the fungicide solution. TIP: Water your trees before you injection them to help with the excavation process and uptake of the fungicide solution.
DISTANCE TO OAK WILT INFECTED TREE:
We’ve touched on this briefly under timing. Trees nearest the infected area are less like to be saved. The ideal treatment zone or area that injections are most successful is 40-120 feet from the infected tree. Treating trees close the infected trees is possible and can be saved, but our success rates are reduced. Treating trees beyond 120 feet is ineffective because as the tree grows it puts on new growth. The fungicide solution moves readily throughout the vertically, but not very horizontally. This means the new growth rings the tree puts on will not be protected. MYTH: I should inject my tree at any point to protect it from oak wilt. FALSE, treat only when your trees are threatened by oak wilt and oak wilt is within 100-120 feet of the tree you are wanting to protect.
TYPE OF INJECTIONS:
Macro-infusion, micro-injection, capsules, syringes are ways of injecting a tree. Only one of these methods is approved by the Texas Forest Service(TFS) and Texas A&M for treatment of oak wilt. That method is macro-infusion…it also happens to be the method that we use. There are arborists out there that use the other methods and have some success, but we choose to use the method backed by TFS and Texas A&M.
What is macro-infusion? The pictures below are trees being treated thru macro-infusion. Macro-infusion is a type of injection that delivers a high volume solution to insure the entire tree treated. Micro-injection implies exactly what it does, it delivers a concentrated about of solution to one specific area as well do capsules and syringes.
FUNGICIDE USED:
We use Alamo fungicide. Alamo has been the leading the fungicide for injecting trees for oak wilt suppression. It is the same fungicide Texas A&M used for its research. There are other fungicides labeled for oak wilt use, but only Alamo is proven (in our eyes). Don’t be fooled by imitations.
If you would like more information on oak wilt please Contact Us. We do not charge for estimates, but a small is charged for consultations. One of our ISA Certified Arborists can develop a treatment plan that is effective and economical.
