P.R. Fisher

A decision-support system for real-time management of Easter lily (Lilium longiflorum Thunb.) scheduling and height—I. System description

Abstract A decision-support system was developed for recommending night and day temperature settings to control the timing and height of Easter lily ( Lilium longiflorum Thunb.). Existing biological models and qualitative rules were combined into an overall model of the response of plant development rate to temperature. A process control algorithm was used to determine appropriate height control actions based on a graphical control chart of plant height over time. A knowledge-based system checked the feasibility of output from the development and height control models and generated a text report. This model was implemented on a personal computer in a program called “The Greenhouse CARE System” and has been linked directly with an environmental computer to control greenhouse temperatures. A companion article describes validation of this model.

A decision-support system for real-time management of Easter lily (Lilium longiflorum Thunb.) scheduling and height--II. Validation

Abstract Computer decision-support systems (DSS) are interactive programs that provide model recommendations in a problem area. An experiment was conducted to validate a DSS for scheduling and height control of Easter lily ( Lilium longiflorum Thunb.) called The Greenhouse CARE System . The DSS was used to recommend temperature settings in three locations (Michigan, California and Denmark) with the goal of producing Easter lilies to predefined flowering and visible bud dates, and to plant height targets. Day and night temperature settings recommended by the DSS were the sole method used to control timing and, secondarily, plant height. Flowering of 50% of plants occurred on the specific target date in two locations and was one day early in the third location. The DSS was less able to achieve a target visible bud date, and information from commercial crops grown with the DSS indicated changes needed to implement a leaf unfolding rate model. Plant height was consistently taller than desired, indicating that growth retardants need to be included in future model recommendations. DSS temperature recommendations were similar to those made by experienced Easter lily producers.