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.