Abstract: The subject invention provides materials and methods for the control of pests, including fungi, oomycetes, nematodes, and weeds, of numerous crops, plants and forests. Advantageously, pests in the soil can be controlled without phytotoxicity. In certain embodiments, the subject invention provides new pesticidal compositions. In preferred embodiments, these compositions comprise an active ingredient component that is formic acid and/or acetic acid, and/or salts thereof. The composition further comprises a second acidic component that enhances the pesticidal activity of the first active ingredient component.