A Morphogenetic Crop Model for Sugar-Beet (Beta vulgaris L.)

Abstract

This paper is the instructions for the proceeding of the International Symposium on Crop. Sugar beet crop models have rarely taken into account the morphogenetic process generating plant architecture despite the fact that plant architectural plasticity plays a key role during growth, especially under stress conditions. The objective of this paper is to develop this approach by applying the GreenLab model of plant growth to sugar beet and to study the potential advantages for applicative purposes. Experiments were conducted with husbandry practices in 2006. The study of sugar beet development, mostly phytomer appearance, organ expansion and leaf senescence, allowed us to define a morphogenetic model of sugar beet growth based on GreenLab. It simulates organogenesis, biomass production and biomass partitioning. The functional parameters controlling source-sink relationships during plant growth were estimated from organ and compartment dry masses, measured at seven different times, for samples of plants. The fitting results are good, which shows that the introduced framework is adapted to analyse source-sink dynamics and shoot-root allocation throughout the season. However, this approach still needs to be fully validated, particularly among seasons.

Change-Point Estimation in the Multivariate Model Taking into Account the Dependence: Application to the Vegetative Development of Oilseed Rape

“…For instance, for WOSR the slope increases between the two phases whereas it decreases for wheat (Miralles et al 2001) or beetroot (Lemaire et al 2008). …”

“…For many species, this relationship is linear and the inverse of the slope is called the phyllochron, that is the time between the appearance of two leaves (Rickman & Klepper 1995). For some species, the number of leaves on the main stem ts with a piecewise linear continuous function with two change-points as observed on wheat (Baker, Allen, Boote, Jones & Jones 1990), rice (Tivet 2000;de Raissac, Audebert, Roques & Bolomier 2004), beetroot (Lemaire, Maupas, Cournede & de Reye 2008) and rapeseed (Jullien et al 2011;Gomez & Miralles 1990). …”

“…In rice, the second phase starts with the beginning of the stem elongation (de Raissac et al 2004) and in beetroot, (Lemaire et al 2008) highlighted a relationship between the date of the change-point and the competition level. All these reasons justify all the more the necessity of determining exactly the dates of the change-points.…”

“…As indicated by (Lemaire et al 2008;Morrison et al 1990), the parameters of the dynamics of the number of leaves (rate and change-point) may vary in particular with the plant density. We thus hypothesized that the change-points could be indicators of the competition between plants.…”

Modeling Inter-individual Variability in Sugar Beet Populations

“…Field experiments were conducted in 2006 by the ITB (Instut Technique de la Betterave sucrière) to investigate the source-sink dynamics of sugar beet growth with the GreenLab model (see [15] for more details on the experimental work). The final population was estimated to be 9.6 plants per m 2 .…”