The present invention relates to a capsule for treating wooden items, trees or a variety of porous structures. The invention is particularly useful for feeding at least one chemical agent into plants and, more particularly, for delivering a chemical agent or chemical agents to the phloem layer of a tree. The chemical agent or agents may be a herbicide or herbicides, or any other tree destroying agent or agents, if the treatment is designed to kill the tree, or fertilizers, fungicides or other medicants or nutrients in various combinations if the treatment is designed to cure the tree from diseases or nutrient deficiencies.
Capsules consisting of generally cylindrical hollow containers and plugs for insertion into predrilled holes in an item or structure to be treated are known. Such capsules have typically been made of a frangible material, or of a hard, brittle, breakable and non-elastic material, such as fiberglass, wood or wood fiber. However, the hollow containers of these known capsules tend to be breakable before they are assembled or even after assembly upon inadvertent application of an external impact. Also the containers of these known capsules are typically used to apply only a single chemical agent to the item or structure.