PLU stickers are used by farmers to track and label their produce for easy identification. They contain important information such as the variety of the produce, the country of origin, and the size of the produce. Additionally, they also help to facilitate the checkout process at supermarkets and grocery stores where the PLU code is scanned at the register to determine the price of the produce. Overall, the use of PLU stickers helps farmers to improve their inventory management, enhance their marketing efforts and provide consumers with vital information about the food they are purchasing.