What are dissolvable capsules that contain pesticides or fertilizers and are inserted into tree trunks?

Dissolvable capsules designed for insertion into tree trunks serve as a method of delivering pesticides or fertilizers directly into the plant's vascular system. This method enhances the uptake of the chemical while minimizing exposure to the surrounding environment. By using implantable capsules, the active ingredients can be effectively contained within a protective coating, which dissolves over time, gradually releasing the intended substances.

This targeted application helps to ensure that the tree receives the necessary treatment without the potential for runoff or environmental harm that can occur with traditional spraying methods. It also allows for a more controlled release, which can lead to better absorption and reduced toxicity to non-target organisms.

In contrast, inoculum refers to any agent used to inoculate something, usually with beneficial microorganisms, and doesn't apply to the specific context of pesticides or fertilizers in capsules. Insecticides specifically target and kill insects, while horticultural oils are typically used as a means to control pests or diseases on various plants, but neither fits the description of capsules designed for tree trunk insertion.