CottonTrace for Seed to Cloth Traceability with IoT and Digital Product Passports

Cotton production involves repeated changes in material form, ownership and quantity, making a garment difficult to trace using disconnected records. We present CottonTrace, a web-based prototype that links eight material stages through quantity-labelled lot genealogy, contract-based validation, an application-managed permissioned-ledger model, off-chain evidence, Internet of Things ingestion and a QR-accessible Digital Product Passport. An explainable detection layer combines robust statistics with domain rules to route suspicious records to auditors. The design is examined against the implementation and the project-reported synthetic evaluation of 18 lots, 61 blocks and 2,488 sensor readings. That evaluation records rejection of invalid operations, detection of edited evidence, eight findings corresponding to planted irregularities, and verification of 12 upstream lots for a garment passport. These observations demonstrate functional integration within the pilot. They do not establish distributed consensus, field accuracy, calibrated fraud probabilities or a complete environmental life-cycle assessment. The main contribution is a transparent workflow connecting deterministic validation, evidence integrity, material attribution and human review in a single cotton traceability prototype.