Sodium 4-chlorophenoxyacetate is primarily used as a plant growth regulator in agriculture. It promotes the growth of crops by stimulating cell elongation and division, leading to increased yields. This chemical is particularly effective in enhancing the growth of fruits, vegetables, and ornamental plants. It is also used to prevent premature fruit drop, ensuring that crops remain on the plant until they are fully mature. Additionally, it can be applied to improve the quality and shelf life of harvested produce. In some cases, it is utilized in research studies to understand plant hormone mechanisms and their effects on growth and development.