The effect of different levels of urea and planting density on the phytochemical characteristics, alkaloids, and yield of the medicinal plant jimsonweed (Datura stramonium L.).

Datura stramonium L. (jimsonweed) from the Solanaceae family is widely used in traditional medicine due to its medicinal properties. This paper investigated the effect of three levels of urea fertilizer (60, 120, and 180 kg ha–1) and three levels of planting density (6, 10, and 14 plants m−2) on the grain alkaloids, chlorophylls a and b content, carotenoids, anthocyanins, and grain and biological yields. A factorial experiment as a randomized complete block design was carried out at the Research and Education farm of Isfahan Agricultural and Natural Resources and Training Center in IRAN in 2018 and 2019. Significant differences were detected between urea levels and plant density for leaf chlorophyll content, carotenoids, and anthocyanins at the 1% probability. Also, hyoscyamine alkaloid levels and scopolamine content are affected by the urea levels at the 1% probability. Moreover, the relationship between phytochemical characteristics and alkaloids with the grain and biological yields in D. stramonium is investigated by path analysis. The results showed that grain yield, hyoscyamine alkaloid levels and scopolamine content is significantly improved by 6 plants m−2planting density and 180 kg ha–1 urea. Core Ideas: The effect of plant density and urea levels on the content of tropane alkaloids in Datura stramonium L. was investigated.The effect of physiological traits and tropane alkaloids on grain and biological yields were further studied by path analysis.Grain yield is significantly improved by 6 plants m−2 planting density and 180 kg ha−1 urea. [ABSTRACT FROM AUTHOR]