Computer-implemented systems and methods for building a database of bales of cotton available for sale, and for electronic commerce of bales of cotton. A fiber quality measurement instrument located in a cotton gin provides fiber quality data substantially concurrently with the making up of cotton into individual bales. The fiber quality measurement instrument is connected through a communications network, such as the internet, for uploading fiber quality data to a database storage device. For electronic commerce, a search engine is connected via the communications network to interrogate the database to select bales having fiber qualities within specified ranges for a candidate buyer.