Sumulong, Ismael D.2026-06-052026-06-052023-05Sumulong, I. D. (2023). Pesticide usage of farmers along the Gantay river in Bacnotan, La Union. [Unpublished Undergraduate Thesis]. Don Mariano Marcos Memorial Stae University - North La Union Campus, Sapilang, Bacnotan, La Union. Lakasa ti Sirib, DMMMSU Institutional Repository.https://lakasa.dmmmsu.edu.ph/handle/123456789/1709Pesticides are major inputs of modern agricultural production; but despite their capability for crop protection against pests and warranty of high crop yields, pesticides can affect the river and human health. In this study, pesticide usage of farmers along the Gantay River in the municipality of Bacnotan, La union is determined. Descriptive survey method was used through the aid of questionnaire and supported by interviews and observations. A total of two hundred fifty-four (254) farmers served as respondents of the study selected through stratified sampling from ten (10) barangays along the Gantay River. Frequency counts, means, percentages, median and ranking were used in the analysis of data. Results show that most farmers use chemical inputs for their crops. Despite the high level of awareness on its effects, pesticides are still used. An action plan was proposed to address or minimize the potential harm of pesticide usage. Keywords: farmers, human health, pesticide, pesticide usage, riveren-USThesis