A dynamic model of potential growth of olive (*Olea europaea* L.) orchards


A model of potential olive oil production is presented, based on a three-dimensional model of canopy photosynthesis and respiration and dynamic distribution of assimilates among organs. The model is used to analyse the effects of planting density (high and super-high density orchards with 408 and 1667 trees ha⁻¹, respectively) and climate change (ΔT of 4°C and CO₂ concentration of 740 ppm) on olive oil production. To evaluate its predictive power, the simulations were tested with published measurements of leaf area, growth and yield for a high density olive orchard cv. ‘Arbequina’ in Cordoba, Spain. The model slightly overestimated (less than 7%) the different measurements reported in the experiment. For all simulations, the maximum yields obtained were in agreement with literature. Simulations showed that climate change had a very small effect on yields due to compensation of the negative and positive effects of temperature and CO₂ on photosynthesis and respiration. However, high temperatures led to some sterile years due to lack of vernalization. The model predicts that super-high density olive orchards achieve higher potential yields than high-density systems and that maximum yields are reached on the third year of the orchard. The advantage of a higher density is a higher interception of solar radiation, especially during the first years of the orchard. In all the simulations, the model predicted a small decrease of the radiation use efficiency for oil production with the age of the orchard as well as an important inter-annual variability (range of 0.11–0.19 g (MJ PAR)⁻¹), indicating that the use of a constant radiation use efficiency may not be adequate to predict oil production.

In European Journal of Agronomy.