DESIGN OF A SINGLE TRUSS TOMATO PRODUCTION SYSTEM (STTPS)

The STTPS is the result of an integrated system design to achieve year-round, continuous, predictable production of uniform quality greenhouse tomatoes. The unique features for successful implementation are: plants grown on transportable benches, effective use of supplemental lighting, computer-assisted management, and environmental and cultural support systems (Ting and Giacomelli, 1991).

The design includes: the greenhouse structural components and their layout; the environmental control and operational strategy; the crop culture system with particular emphasis on its integration with the transport system; the mechanization system for the crop transport, handling, and labor efficiency; the management, organization and description of labor tasks; and the decision support software for operations management and planning.

The crop production is based on a plant growth model whereby tomato plants are allowed to develop only a single truss of fruit. Harvest date and fruit yield were found to be strongly dependent upon the total PAR radiation available, assuming that other environmental factors (temperature, carbon dioxide, nutrients) were not limiting. Desired target harvest dates and yields could be achieved by providing daily supplemental HPS lighting during the low natural light period of the year. High density plantings of the relatively low crop provided a dense, closed canopy at a uniform height for efficient interception of the available light. An ebb and flood culture system within the transportable benches provided uniform water and fertilization, and allowed transport of the bench from the growing area to a labor work area. Variations of NFT hydroponic systems can be considered as an alternative to ebb and flood which may have potential for reducing investment and operating costs.