Evaluation of artemisinin contents as affected by soil and water management strategies under gravity-drip irrigation system in Samaru, Nigeria

Abstract

Malaria has been among the dangerous diseases not only in Nigeria but Africa as a whole. Artemisia crop has an artemisinin, which is a strong anti- malaria drug. However, despite its importance in curing this disease, it is only produced under rain-fed but hardly produced under irrigation in Nigeria. The experiment consisted of three levels of irrigation water application at 100, 80, and 60% ETo (reference evapotranspiration); two mulch levels (rice straw mulch and no mulch) giving a total number of six treatments, replicated three times, totaling eighteen treatments laid in Randomized Complete Block Design (RCBD). The soil moisture was monitored throughout the crop growing season with access tubes installed at different incremental depths of 0-20 cm, 20-40 cm and 40-60 cm below the soil surface. The artemisinin content was determined in the Faculty of Pharmaceutical Sciences, Ahmadu Bello University, Zaria. The artemisinin content obtained ranges from 0.27 % w/w to 1.84 % w/w. The least artemisinin content was obtained from the treatment with irrigation at 60% ETo with no mulch. While the highest value was obtained with irrigation at 100% ETo with rice straw mulch. The artemisinin content of artemisia annua is affected by water stress. Irrigating the crop fully results in higher artemisinin content of artemisia annua followed by 20 % deficit. The least artemisinin content of artemisia annua was obtained at much water stress of 40 %. The study, recommends a full irrigation could be practiced for effective production of artemisia crop under drip irrigation. However, up to 40 % irrigation water deficit could be applied in areas of high water scarcity. Moreover, since rice straw is cost effective, it is recommended for use as mulching material for the cultivation of artemisia crop under irrigation.