Knowledge-based control systems for single stem rose production - Part II: Implementation and field evaluation

Field evaluations of knowledge-based control systems (KBS) for single stem rose production were performed. Two fuzzy, inference systems (FIS) for automated selection of daytime and nighttime temperature were incorporated into the design of the integrated environmental control systems. Assessments of systems' operational characteristics for daytime and nighttime temperature settings, single stem rose performance, and potential supplemental heating energy savings were performed over three consecutive crops. It was found that the KBS is capable of making a critical decision for daytime temperature settings based on the principle of economic optimization. Single stem roses produced by the KBS were graded by stem length. Overall crop quality was in the medium to high grades for the first two tests and poor for the last test. From the investigations, it was learned that undesirable low daytime temperature and light level during plant establishment promotes flower bud abortion. Potential benefits of heating energy savings using the KBS were estimated compared to a blueprint set point schedule (21°C). A moderate reduction in heating energy costs could be realized by using the KBS. The new method demonstrated the success of incorporating a FIS into decision support for daily environment control decisions, where conflicting economic goals must be dynamically re-evaluated as crop conditions and weather vary.