Pesticides is the general term for a formula that is used to poison or kill certain pests, usually for the purpose of guarding against an infestation of these pests.
The most common pesticides, usually found in the gardening section, are herbicides, which kill unwanted plants. (Think of RoundUp which kills medicinal dandelions that pop up in monoculture grass lawns.)
Insecticides are used to kill unwanted insects and pests from crops. Just make sure to avoid killing any beneficial insects that you want around your hemp plants.
Another pest control option are fungicides which is used to treat fungi, like fusarium, and their spores.