A review on the growth, yield and oil contents of Brassica under rainfed conditions

Brassica species have been considered an important source of oil in worldwide. These are being cultivated either as a vegetable, fodder or oil purpose. Their oil can be used for cooking and in different industries depending on their oil contents. The oil containing high quantity of monounsaturated fatty acids (oleic acid and linolenic acid) is highly suitable for cooking. Phytochemicals present in Brassica reduces the oxidative stress and prevent cancer in human. The growth and yield of Brassica species in rainfed areas depends on rainfall. Rainfed agriculture is most commonly practiced by poor community of many countries including Pakistan. The problems with rainfed areas are irregularity in rainfall, results in waterlogging due to heavy rainfall or drought stress due to low rainfall. The other problems are soil erosion, nutrient deficiency, weed infestation and crusting that limit the growth and yield of crops of these lands. Brassica species are highly susceptible to drought stress from flowering to seed producing stage, their oil contents reduced due to water stress. This review article highlights the growth, oil content and yield of various Brassica species under rainfed conditions. It also highlights the Brassica species that performs best in terms of growth, oil content and yield in rainfed conditions. Many numbers of studies reported that Brassica has high growth rate, fresh and dry biomass, if rainfall is just before or after the flowering stage. Oil contents reduce when precipitation rate is low, but some varieties have been reported having high growth rate, oil content and biological yield in rainfed condition. These varieties should be recommended to farmers for cultivation in rainfed areas. © 2021 The Author(s)