Analysis of the Actual State of Late Maturing Citrus Cultivar Greenhouses

This study aims to analyze and propose improvements for greenhouse structures and cultivation environments suitable for late-maturing citrus.From March to November 2023, a survey was conducted among 28 farmers in Jeju and inland areas.The results showed that Jeju farmers mainly use multi-span greenhouses based on the disaster-resistant standard 08-citrus-1 type, originally installed for Satsuma mandarins.Inland farmers primarily used single-span greenhouses with various specifications such as width, length, and eave height.The average width of single-span greenhouses was over 8.0 m, and the eave height was between 2.4 m, while the average width of multi-span greenhouses was less than 6.0 m, with eave heights between 3.9 m.Single-span greenhouses used 2.1 mm rafters, while multi-span greenhouses used 2.1 mm rafters.Most single-span greenhouses used natural ventilation, while multi-span greenhouses used side and roof ventilation.Heating consisted of fan heaters, while some multi-span greenhouses used radiators and hot water heating.In terms of the planting environment, single-span greenhouses had tree heights of 2.7 m and canopy widths of 2.7 m, with 2.0 to 5.0 trees planted, spaced between 3.1 m per span.Multi-span greenhouses had tree heights of 2.8 m and canopy widths from 4.0 m, with 2.0 to 3.0 trees planted, spaced between 3.7 m per span.When planting three trees per span in a single-span greenhouse and two trees per span in a multi-span greenhouse, it was determined that widening the greenhouse width and increasing the eave height are necessary to create a suitable environment for growing citrus plants, considering canopy width, tree height, and ventilation.Based on these findings, this study suggests suitable greenhouse structures and environmental management improvements for late-maturing citrus, providing a basis for developing a greenhouse model for high-quality citrus production.