Flowering expert system development for a phenology based citrus decision support system

The authors are part of a Florida group of research, extension and grower personnel engaged in development of an integrated Decision Support System (DSS) to provide growers with recommendations for their citrus production practices. To assist growers in the timing of production practices, a JAVA-based DSS was developed, that includes modules for phenology, scheduling of recommended production practices, GPS-GIS on field maps that allow the system to be block specific and a record keeping system for applied production practices. Best management practices for maximum efficiency often require that a given practice be applied at a specific stage of vegetative or reproductive development. Because of the variable flowering dates that occur in citrus under Florida conditions, the proper timing of any given production practice may vary by as much as 2 months from one. season to another, therefore the scheduling system operates through phenology models. To drive phenology timing, a flowering expert system was developed to predict flowering intensity, start of flower bud differentiation and date of bloom. The models used were based on studies of accumulated cool winter temperatures and flower bud induction, transition temperatures that initiate flower bud differentiation and spring temperatures during flower bud development to full bloom. Recommendations for avoiding multiple blooms and altering flowering intensity are included in the expert system. An overview of the production practices scheduling program is presented. This program gives growers tools to partially manage the flowering process in Florida citrus.