More about Micro-Injection
The following paragraphs are collections from various articles written primarily by some everyday people, a few arborist, a retired plant pathologist, and write ups from Arbor magazines, all having a positive and honest approach with regards to micro-injection. I am personally in favor of micro- injection for the reasons of minimal damage, protecting the environment and efficiency of uptake results . Enjoy the reading and you decide.
Recent advancements in technology have led to significant improvements in this application method of microinjection options. These new systems combines advances in chemistry development with a highly portable, convenient, that delivers ultra low dose applications. Tree microinjection will offer the ability to treat trees where soil treatments are not practical. Environmental conditions, location limitations, budget and equipment availability will determine which application method to choose. In general, you can treat more trees per day applying microinjection for higher productivity, it usually only takes one applicator with proper training to treat a tree.
Micro-injection is controversial! It provides for convenient, environmentally sound placement of small amounts of systemic pesticides directly into a tree, yet it wounds trees. This method of pesticide delivery is widely used by arborist world wide; but is it used appropriately? Injection wounds serve as points of entry for pathogenic organisms, but wouldn't a pruning cut do the same? The answers to these questions and more depend on the tree, the pest, the economics of labor, training, materials, and the perceptions of the clientele.
Plus, you can't leave out evidence from the maple syrup world. These trees, are tapped each year creating holes bigger in diameter than the typical trunk flare injection tee and have sap [energy/carbon] extracted. Some sugar bushes have been tapped successfully for 10-14 decades.
Thus the dosage and means of application are critical to success. The injection of chemical into root flares (below soil level) in large volumes of water (macroinjection) provides thorough distribution of chemical in the crown. Trunk flare (above soil level) microinjection is a better option in my opinion. It's efficacy compared to macroinjection has been thoroughly researched and it demonstrates efficient uptake and maximizes distribution upto the canopy and most important of all the lesser damage factor due to the reduced number and size of the drill portals. Wound closure is far much faster due to the smaller and shallow holes. Movement downward occurs only when the water column in the tree is broken by air that is allowed into the tree during drilling. This movement downward is not extensive and should not be counted on to provide significant control below the injection site.
Injections and implants administered by untrained homeowners are not recommended. The procedure should be done only by professionals who have received training in the method to prevent serious damage to the tree. These professionals should use newer methods that require smaller, very shallow holes that penetrate no deeper than the current year's growth increment. Most holes should be no larger than 1/4 inch in diameter. In most cases holes should be no deeper than 1 inch below the bark layer, and under no circumstances should they be deeper than 1 1/4 inch. Implants and injections should be above the trunk flare level of the tree, not into the roots below the soil level. Minimize the number of separate injuries inflicted, and the depth of injuries can help a tree cope with wound closure, as the tree’s natural sap and healing process will quickly close the wound. Trees have a natural defense response to wounds by producing callus tissue. The holes will close within the growing season.
With macroinjection into the root flare, the soil is excavated to provide a greater area for more injection tees to be well-spaced around the trunk base, resulting in greater damage to the base of the tree. Drill wounds in this area when covered with soil, showed evidence of internal or external damage, delayed wound closure, and wetwood problems, and not to mention bacteria and canker infections or other pathogens. Injuries in the root flare below soil level tend to be slow to recover because of all the above factors, and the greatest drawback is the tree’s lack of ability to stimulate only limited wound closure.
After many years of macro injections, I have become most horrified at the savage way in which trees are injected at the root flare, drilling an excessive numbers of large drill holes, then covering with dirt and debris into the wounds. This is pure stoneage technology and a serious violation to the tree, exposing the wounds as points of entry for soil borne pathogenic organisms, insect invasion, canker, weeping, wetwood problems, tissue decay, bark separation and wound closure delay. Why, the big bother and fuss about sterlizing your equipment? Trees deserve better treatment too!
Propiconazole being systemic moves upward through the xylem to the canopy. The product pushers claim by injecting into root flare below soil level, you achieve better protection for the tree and wound closure is faster? Some protection was achived, but was the risk of excessive damage worth it.....and .....They thought........ " YES." They obviously flunked anatomy, with total disregard for the tree's overall health. Repeated injuries in the root flares are slow to recover for lacking a chemical barrier to isolate infection and disease. Microinjection above the trunk flare, and up the trunk stem, first gets the job out of the dirt, reduces the of drill size by half and at least 2/3 far less drill holes than applied at the root flare. The above trunk flare injection, offers better protection, less exposure to canker infection, insects and soil borne microbes and still maximizes the uptake distribution to the leaves and then to the roots.
In order to be effective, the fungicide must be present at adequate concentration. Thus the dosage and means of application are critical to success. Microinjection of small volumes of concentrated chemical into the trunk, has proven it's efficacy and has been thoroughly researched and demonstrates uptake that provides thorough distribution of chemical in both the crown and to the roots. The chemjet can be filled with 5,10, 15, 20 mils of the injection products forthe exact prescription needs for the tree. The injections or implants are required at two to six inch intervals around the circumference of the tree, in accordance to the application rate prescribed on the label. The amount of chemical and volume of solution to inject are usually based upon the diameter of the tree.
Root flare injection can severely damage the inner bark and cambium below the soil line. These injuries often do not repair efficiently or effectively. The problem with the root flares is that they don’t have protection zones that isolate diseases. This damage invites insects and fungi infestation. Also this is the most important transition zone for water and nutrients to move up to the canopy and the solutes back down to the roots. Excessive damage in this critical zone will ultimately determinate the trees vigor and health and eventual death is emanate.
The many experiments conducted with drill holes give information applicable to below soil root flare injection wounds. In elm, the injection holes that touched the internal column of discolored wood spread to form large columns. The injection holes that were surrounded by clear healthy wood were walled off to small columns. Also, the decayed wood in the columns that joined with the already present central column. Injections properly spaced in position on the tree lower trunk flare area, and spaced over time, will not cause serious internal injury. When trees are injected repeatedly over time, the discolored columns associated with the injection wounds begin to coalesce. The volume of wood that would normally hold energy reserves is reduced.
Injections and implants are being used for a great number of reasons, from supplying essential elements to adding many types of chemicals to combat insects and fungi. Care must be taken in the treatment so as not to cause more injury to the tree than it had originally. Injections properly done may be beneficial. Proper injections and implants should be as shallow and as small as possible, minimize major, long-term tree injuries, and at above the base and lower trunk of the tree, not into the roots.
Most of the transport in a tree occurs in the current growth ring. There is no need to inject beyond this wood. In many cases it is not the wound, but what is put in the wound that causes injury. Several injection methods are now using very small holes-microinjections. Injection holes, or any type of wound, should never be directly above or below other wounds. Proper injections require a high degree of skill.
(XMS .. Xylem Mobile Systemic)
Photos and illustrations - Copyright Chemjet Trading Pty,Ltd, Australia
"Propiconazole, a systemic fungicide, (XMS .. Xylem Mobile Systemic) does not require high dilution rates with water, so treatment is considerably faster, and there is less tissue injury at the injection site as it has a near neutral pH factor."
Why are trees injected into the root flare. I believe some of the reasoning was that "Propiconazole, is a systemic fungicide, being.. (Xylem Mobile Systemic) meaning it moves upward through xylem and vascular system. Water movement is relative to the transpiration pull, transporting water and nutrients from the roots to the canopy. Photosynthesis converts the nutrients to sugar and starch and these solutes (which are food and energy) are then transported to all parts of the tree including the roots via the phloem. Now that the tree is being injected, the fungicide first moves upward to the leaves and then downward with the solutes providing a preventive protection throughout the tree from the oak wilt pathogen. The other idea is that since the root flare is a larger area, you can apply more injection sites at 3-4 inches apart and acquire faster distribution. Wrong !. Water movement is relative to the rate of transpiration pull which is in turn relative to photosynthesis. The entire process is also relative to soil moisture, air temperature, humidity, and the amount of sun light exposure. Because you have more injection sites does not mean you are going to get more fluid to the top of the tree. Only so much water can move within the tree, and again that is relative to photosynthesis and transpiration pull. All you have really accomplished is a lot of extra wounds, when a fewer number of injection site would accomplish the same goal as regard to uptake and distribution. To cover up your dirty deed, you fill in all that damaging evidence and fruitless work with DIRT, subjecting your tree to unseen damage, insect invasion and infection.
With the Chemjets you need one injector for each diameter inch place evenly around the trunk flare, and with a very small drill bit of 11/64" or 4.2 mm versus 5/16' or 8 mm. Now you have accomplished the same goal with less work, out of the dirt, and far less damage for the tree to cope with. Understand that when a tree is wounded, the healing process or wound closure starts immediately. You can inject your trees above the trunk flare and achive effective results of uptake and distribution.
In one trial report by the Queensland Dept. of Natural Resources, a researcher accessed the Chemjet Injector Syringe as the safest method of application of herbicides, insecticides and fungicides available.
With the Chemjet Injector Syringe, you visit the tree once..... JOB's DONE !
It is generally true that the older a tree lives, the stronger its defense to disease and injury. Therefore, biological theory would suggest that long-lived trees have a defense mechanism that would allow them to sustain centuries of insects damage, wind storms, and repeated boring by birds such as yellow-belly sapsuckers. The small wounds created should heal rapidly and will likely be insignificant injuries.
Tree Injection Process & Advantages
1 ENVIRONMENTAL SAFETY: Chemical injected into trees via properly designed systems, with effective injection site sealing poses almost zero risk of chemical escape.
2 MORE TARGET SPECIFIC : Beneficial insects, mammals and birds are generally unaffected by internal tree application of pesticides, only insects consuming plant tissue or fluids are at risk.
3 GREATER PERSISTENCE : Numerous trails with a wide range of pesticides show much longer periods of activity of material injected as compared to the same material sprayed on the outside of trees, amongst other factors, due to protection from rain and surface water as well as the degrading effects of sunlight.
4 CHEMICAL MINIMIZATION : Numerous tests indicate that substantially less quantity of the same chemical is required to achieve the same or better result when injected as against air born spraying or ground application.
5 PUBLIC AND OPERATOR SAFETY : By the elimination of drift and the surface application of pesticides, risks of contact by the general public, operators and other workers is greatly reduced.
6 REDUCED RISK OF LITIGATION : With the pesticide sealed within the plant, elimination of drift and the possibility of ground or surface water contamination, potential for litigation is low. Tree injection is widely used in such places as, residential urban areas, and ranch land etc.
7 PUBLIC ACCEPTABILITY : Increasing public pressure is making it ever more difficult for horticulturists and contractors generally to apply pesticides. The writers experience during numerous exercises of injecting trees in public places has been that when the operator explains the process to people without exception approval is immediate.
8 WOUND REDUCTION : Minimal sized injection points within the microinjection range
The Measure of a Tree
Since the beginning of time, throughout the entire world forests, all trees intentionally grow under stressful conditions. Every climatic region and climatic eco-system will challenge and test a tree's ability to grow and survive. In all our forests, survival and time is what Ancient Champion Trees really are made of !
Disclaimer: This article may contain pesticide recommendations that are subject to change at any time. These recommendations are provided only as a guide. It is always the pesticide applicator’s responsibility, by law, to read and follow all current label directions for the specific pesticide being used. If any information in these recommendations disagrees with the label, the recommendation must be disregarded. No endorsement is intended for products mentioned, nor is criticism meant for products not mentioned. The Writer assumes no liability resulting from the use of these recommendations. The information given herein is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement is implied.
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