Treating Dutch Elm Disease With Fungicides
Dutch elm disease is one of the most deadly of all tree diseases and has single-handedly crippled elm populations in many parts of the country. That said, those who identify the problem quickly enough may be able to keep their elm trees alive using powerful fungicides. If you would like to learn more about how these chemical substances work, read on. This article will introduce you to the use of fungicides in treating dutch elm disease.
Overview
Many different fungicidal agents may be used to treat dutch elm disease. The choice of an appropriate fungicide is usually determined by the means of disease transmission. Certain fungicides are reserved for use when the disease has been spread through bark beetles. Other fungicides are more appropriate when the disease has spread through root graft. This simply refers to places where the roots of one tree have become tangled up with the roots of neighboring trees.
Regardless of the specific fungicide used, it will be introduced in a liquid form to the tree's vascular system. This is accomplished by injecting the fluid into the base of the tree, where it will then be spread throughout by natural capillary action. The most important factor here is the amount of fungicide that is injected: too little and the drug may not be strong enough to eradicate the disease, too much and the tree itself may suffer damage form the fungicide.
Injecting Fungicide
There are two different injection methods by which a fungicide can be introduced to an ailing tree. These are known as microinjection and macroinjection. As its name would suggest, microinjection involves the introduction of relatively small volumes of fungicide. The key here is that this fungicide is in a highly concentrated state. Macroinjection takes more or less the opposite approach. That is, it utilizes a much higher volume of fungicidal solution. Here, however, the solution is much more diluted. Both macro- and microinjection require that a series of holes be drilled in the trunk of the tree. These holes allow the fungicide to be pumped into the tree using either a pressurized or a non-pressurized injection tool.
Studies have shown that macroinjection represents a more effective way of ensuring that the fungicide reaches even the most distal portions of the tree. This reduces the likelihood that the disease will remain living—and then spread out again later on. Yet macroinjection has also been shown to increase the likelihood of such problems as secondary infections, injection wounds, and related decay.