As cotton plants approach flowering, their plant structure and fruit load have profound effects upon subsequent growth and development throughout the season. SQUAREMAN is one of two expert systems comprising COTMAN, a computer-aided cotton management system. The primary purpose of the SQUAREMAN expert system is to signal aberant crop development prior to flowering. Aberant crop development is determined by comparison of actual growth curves to a pre-determined standard (the target development curve) and by evaluation of square shed. Interpretation of growth curves is based on position of curve (three options), slope of curve (four options) and square shed (two options). One or more of eight decisions rules are triggered by combinations of these options. The decision rules and their corresponding triggers are presented.