Evaluation of the productivity of Cyperus esculentus L. cultivated in different phytogeographical locations in Egypt (ex-situ conservation) and its anti-oxidant activity

Background and objectives The conservation and management of threatened and endangered species is a tremendous challenge that must be addressed to achieve the goal of halting the loss of plant biodiversity. According to the IUCN Red List of Threatened Species, Cyperus esculentus lies in the least concern category. This means that it has been evaluated against the Red List criteria and does not qualify for critically endangered, vulnerable, or near threatened. In Egypt, the people depend mainly on the wild growing tubers, whereas the area of land cultivated with tiger nut is becoming very small. This is highly affecting the population of the plant and explains the need to introduce its cultivation in different phytogeographical regions of Egypt. Materials and methods Tubers of C. esculentus were obtained from Wady Elsheh Farm, Assuit Governorate, Egypt, and were cultivated in four different locations during two planting periods. Physical and chemical properties of the soils were determined. In addition, water used for irrigation was analyzed. Moreover, growth and yield parameters were recorded. The 80% methanol extract of powdered tubers was prepared using the ultrasound-assisted extraction, and the antioxidant activity was determined using the 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay. Results and conclusion The obtained results showed that soil type and water used for irrigation had a significant effect on plant growth, that is, plant height and fresh and dry weight of herb during the two seasons. Moreover, the four extracts of samples obtained from the four locations exerted remarkable antioxidant activity (83.4, 92.4, 90.7, and 65.1%, respectively), which could be attributed to high flavonoids content of the tubers. The soil and water for irrigation at Wadi Elsaeida, Aswan Governorate, and El-Bahrya Oasis are more suitable for the production of C. esculentus tubers.