Simulating Growth and Development of Tomato Crop

Abstract

Crop models are powerful tools to test hypotheses, synthesize and convey knowledge, describe and understand complex systems and compare different scenarios. Models may be used for prediction and planning of production, in decision support systems and control of the greenhouse climate, water supply and nutrient supply. The mechanistic simulation of tomato crop growth and development is described in this paper. The main processes determining yield, growth, development and water and nutrient uptake of a tomato crop are discussed in relation to growth conditions and crop management. Organ initiation is simulated as a function of temperature. Simulation of leaf area expansion is also based on temperature, unless a maximum specific leaf area is reached. Leaf area is an important determinant for the light interception of the canopy. Radiation shows exponential extinction with depth in the canopy. For leaf photosynthesis several models are available. Transpiration is calculated according to the Penman-Monteith approach. Net assimilate production is calculated as the difference between canopy gross photosynthesis and maintenance respiration. The net assimilate production is used for growth of the different plant organs and growth respiration. Partitioning of assimilates among plant organs is simulated based on the relative sink strengths of the organs. The simulation of plant-nutrient relationships starts with the calculation of the demanded concentrations of different macronutrients for each plant organ with the demand depending on the ontogenetic stage of the organ. Subsequently, the demanded nutrient uptake is calculated from these demanded concentrations and dry weight of the organs. When there is no limitation in the availability at the root surface, the actual uptake will equal the demanded uptake. When the root system cannot fulfil the demand, uptake is less, plant nutrient concentration drops and crop production might be reduced. It is concluded that mechanistic crop models accurately simulate yield, growth, development and water and nutrient relations of greenhouse grown tomato in different climate zones.

Dynamic modeling of mineral contents in greenhouse tomato crop

“…Protected environment models are necessary if one wishes to perform some optimization in production [14]. Although several studies involving the modeling of greenhouse tomato growth can be found [15,16], these models do not consider nutritional relations for the efficient management of mineral nutrition and some are based on variations of mineral concentration in nutrient solution or on drained solution [17].…”

Comparison of Climate and Production in Closed, Semi-Closed and Open Greenhouses

“…Fresh weights of the harvested fruits were recorded weekly. Scenarios were calculated, by using the plant growth model INTKAM (Marcelis et al, 2009), to investigate the contribution of the climate factors to the final production increase. Calculation started by inputting the actual CO 2 concentration, air temperature and VPD of the open greenhouse.…”

Evapotranspiración de referencia estimada con Fao-Penman-Monteith, Priestley-Taylor, Hargreaves y RNA

“…La superficie de referencia corresponde a un cultivo hipotético de pasto con características específicas (Allen et al, 2006;Marcelis et al, 2009).…”

“…The reference surface corresponds to a hypothetical grass crop with specific characteristics (Allen et al, 2006;Marcelis et al, 2009).…”