Faye A. auteur aut IRD Sine B. auteur aut IRD Chopart J. L. auteur aut IRD Grondin Alexandre auteur aut IRD Lucas Mikaël auteur aut IRD Diedhiou A. G. auteur aut IRD Gantet Pascal auteur aut IRD Cournac Laurent auteur aut IRD Ming D. auteur aut IRD Audebert A. auteur aut IRD Kane A. auteur aut IRD Laplaze Laurent auteur aut IRD text journalArticle eng text/pdf reformatted digital access Pearl millet is able to withstand dry and hot conditions and plays an important role for food security in arid and semi-arid areas of Africa and India. However, low soil fertility and drought constrain pearl millet yield. One target to address these constraints through agricultural practices or breeding is root system architecture. In this study, in order to easily phenotype the root system in field conditions, we developed a model to predict root length density (RLD) of pearl millet plants from root intersection densities (RID) counted on a trench profile in field conditions. We identified root orientation as an important parameter to improve the relationship between RID and RLD. Root orientation was notably found to depend on soil depth and to differ between thick roots (more anisotropic with depth) and fine roots (isotropic at all depths). We used our model to study pearl millet root system response to drought and showed that pearl millet reorients its root growth toward deeper soil layers that retain more water in these conditions. Overall, this model opens ways for the characterization of the impact of environmental factors and management practices on pearl millet root system development. specialized 076 068 14 7 e0214182 [18 p.] 2019 1932-6203 https://www.documentation.ird.fr/hor/fdi:010077006 10.1371/journal.pone.0214182 1932-6203 [F B010077006] https://www.documentation.ird.fr/hor/fdi:010077006 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers19-10/010077006.pdf IRD - Base Horizon / Pleins textes 2019-11-05 2025-02-24 fdi:010077006 fre