Assessment of a set of rapeseed (Brassica napus L.) varieties under waterlogging stress at different plant growth stages

Abstract

Rapeseed (Brassica napus L.) crop has a high yield potential in Morocco, particularly in the Gharb region. However, this area is subjected to relatively frequent water floods usually accompanied with soil waterlogging, which is harmful for the crop. This study aimed to assess the behavior and productivity of four Moroccan varieties under waterlogging stress conditions at four plant growth stages, against the control (absence of waterlogging). A field trial was carried out at the INRA experiment station of Allal Tazi during 2013/2014, and a pot experiment was conducted under shelter at the National School of Agriculture of Meknes during 2014/2015. The results obtained show that waterlogging stress significantly affected most of the studied parameters for all varieties and that germination and post-emergence seedling stages were the most sensitive to waterlogging stress conditions. Particularly, seed yield was drastically reduced for all varieties, and the reduction rate ranged from 19% for “INRA-CZH3” to 73% for “Narjisse” when waterlogging happened under rosette and young seedling stages, respectively. Overall, the variety “INRA-CZH3” presented the best agronomic performance and was the most tolerant to waterlogging occurring at different plant growth stages. Therefore, we recommend cultivation of this variety in the Gharb area. Its tolerance to such stress conditions is certainly attributed to its developed root system, its high seedling vigor and its large collar diameter. The two latter traits presented a high correlation with seed yield components and, thus, we recommend their use as selection criteria to breed for waterlogging rapeseed tolerance.