03361naa a2200289 a 450000100080000000500110000800800410001902000220006002200460008202400570012810000170018524501490020226000090035150003530036052020630071365000110277665300280278765300130281565300200282865300210284865300370286965300250290670000150293170000150294670000170296177300930297810652372025-06-13       2025    bl uuuu     u00u1 u    #d  a978-94-62614-24-6  a0567-7572 (print); 2406-6168 (electronic)7 ahttps://doi.org/10.17660/ActaHortic.2025.1425.92DOI1 aBERRUETA, C.  aRecalibration and validation of VegSyst model for soil-grown greenhouse tomato cultivated in Uruguay. [Conference paper].h[electronic resource]  c2025  aArticle history: 31 March 2025. -- Correspondence: Cecilia Berrueta, E-mail: cberrueta@inia.org.uy -- In: ISHS Acta Horticulturae 1425,  International Symposium on Models for Plant Growth, Environments, Farm Management in Orchards and Protected Cultivation - HorchiModel2023. -- Editors: F.D. Molina-Aiz, L. León Moreno. -- Place: Almería, Spain.  aABSTRACT.- The VegSyst simulation model has been developed for use in an on-farm decision support system (DSS) to estimate crop nitrogen (N) and irrigation requirements of different vegetable crops in the Mediterranean Basin. VegSyst simulates dry matter production (DMP), crop N uptake and crop evapotranspiration (ETc). Then it was adapted to simulate also daily uptake of K, P, Ca and Mg. The only inputs are readily available daily climatic data of air temperature, solar radiation and roof transmissivity, plus the dates of the crop. In this study, VegSyst V3 was calibrated and validated for greenhouse tomato cultivated on soil in Uruguay (South America) in autumn and spring seasons. Five tomato crops, three autumn and two spring crops grown in seasons 2019, 2020 and 2021, were used for model calibration (Spring-19 and Autumn-20) and validation (Autumn-19, Autumn-21 and Spring-21). Even though the model is driven by thermal time, different calibration was necessary for the autumn and spring growing seasons due to differences in solar radiation and relationship between cumulative thermal time (CTT) and cumulative solar radiation for a given CTT. The major change introduced into the existing VegSyst model was the substitution of Penman-Monteith equation adapted for Mediterranean-type greenhouses and the Almeria Radiation equation calibrated for southeastern Spain by Hargreaves equation adapted to plastic greenhouses. Recalibrated VegSyst accurately simulated crop biomass production, ETc, crop N and K uptake over time for both, autumn and spring cycles according to statistical indices. The performance of the model to simulate ETc was very good, even better than DMP and nutrient uptake. A decision support system based on recalibrated VegSyst model will be developed to assist farmers and advisers in daily calculation of irrigation and nutrient concentration; aiming to improve crop yield, water and nutrient use efficiency and reduce environmental burden. © 2025 International Society for Horticultural Science. All rights reserved  aTOMATE  aCrop evapotranspiration  aModeling  aNitrogen uptake  aPotassium uptake  aSISTEMA VEGETAL INTENSIVO - INIA  aSolanum lycopersicum1 aGRASSO, R.1 aGARCIA, C.1 aGALLARDO, M.  tActa Horticulturae. 2024, 1425, p.63-70. https://doi.org/10.17660/ActaHortic.2025.1425.9