Clermont Dauphin Cathy auteur aut IRD Suvannang N. auteur aut IRD Hammecker Claude auteur aut IRD Cheylan V. auteur aut IRD Pongwichian P. auteur aut IRD Do Frédéric auteur aut IRD text journalArticle eng text/pdf born digital access Rubber tree cultivation is presently expanding rapidly into dry subhumid areas. As a consequence, trees face a long dry season. Low growth rates are delaying the start of tapping. The relationship between the growth rate and the soil water availability is not clear. Therefore, we studied the origin of low growth rates. For that we analyzed the relationships between growth, plant water stress, and soil water availability along a toposequence with a soil depth gradient. The plantation of 3-year-old Hevea brasiliensis trees was located in northeast Thailand. Tree circumference, predawn leaf water potential (p), soil water potential (s), and micrometeorological parameters were monitored from 2007 to 2010. Results show spatial and temporal variability of growth with a threshold value of leaf water potential of -0.4 MPa for growth. This leaf water potential threshold was not associated with very dry soils as soil water potentials were higher than -0.05 Mpa. But the leaf water potential threshold was associated with a high air vapor pressure deficit higher than 3-4 kPa. Leaf water potential decreased when the soil at the bottom of the slope was saturated in the rainy season. These results provide, for the first time, evidence that soil water shortage is unexpectedly not the main cause of low growth rates. Dry air in the dry season and waterlogging in rainy season are major constraints. specialized Agronomic diagnosis Radial growth Leaf water potential Soil water potential Air vapor pressure deficit Waterlogging Mortality Toposequence Suboptimal area Immature Hevea Hevea brasiliensis 072 076 068 33 3 531-538 2013 1774-0746 https://www.documentation.ird.fr/hor/fdi:010060378 10.1007/s13593-012-0129-2 1774-0746 [F B010060378] https://www.documentation.ird.fr/hor/fdi:010060378 https://www.documentation.ird.fr/intranet/publi/2013/07/010060378.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2013-07-29 2017-08-23 fdi:010060378 fre