Supply chain transparency remains a critical challenge in developing economies, where complex networks often obscure product origins and ethical practices. This research investigates blockchain technology's potential to enhance transparency in agricultural and textile supply chains. We developed and pilot-tested a blockchain-based tracking system with 45 suppliers across Nigeria, India, and Colombia, monitoring 2,300 product batches over eight months. Results demonstrate 96% accuracy in product traceability and 42% reduction in counterfeiting incidents. Economic analysis reveals implementation costs decrease by 60% when deployed at scale. The study provides a practical framework for blockchain adoption in resource-constrained environments.