Effects and management strategies to mitigate drought stress in oilseed rape (Brassica napus L.): a review

Oilseed rape (Brassica napus L.) is an important oilseed crop worldwide. Drought is the most detrimental environmental factor affecting the crop plants from germination up to maturity. A complete perspective of the effect of drought is crucial in understanding the influence of climate variability on rape cultivation. Water deficit stress affects morphology, physiology and development of rape crop. The aim of this article is to present an outline of the effects of drought stress on the growth, physiological processes, yield and quality parameters of rape crop. When drought stress occurs at critical stages, both short and long term, it can adversely affect important growth and physiological processes like leaf area, root growth, shoot growth, excised leaf water loss (ELWL), relative water content (RWC), photosynthesis and water use efficiency (WUE) by disturbing stomatal adjustment, producing reactive oxygen species (ROS), lowering stomatal conductance and destroying the chlorophyll and other pigments. Rape is more susceptible to water deficit stress during reproductive stages which ultimately affect the yield and oil quality. Some important management strategies for drought mitigation in rape, including use of compatible solutes, nutrients, plant growth regulators, different planting methods are also mentioned and discussed in this review paper.