An adaptive abiotic stresses strategy to improve water use efficiency, quality, and economic benefits of Panax notoginseng: Deficit irrigation combined with sodium chloride.

It is still a long-term challenge to decrease root rot and improve saponin content of Panax notoginseng , thus economic benefits in Guangxi and Yunnan provinces, China. The objective of this study was therefore to propose a promising abiotic stresses strategy: deficit irrigation combined with sodium chloride (DISC) to cope with the challenge. A two-year field experiment was conducted to explore the effects of deficit irrigation combined with sodium chloride on physiological traits, yield, quality attributes, water use efficiency, and economic benefit of Panax notoginseng in 2018 and 2019. Experiment treatments consisted of two deficit irrigation levels [ D L , light deficit level: irrigation upper∼lower limit (80–65 %) θ FC ; D M , moderate deficit level: irrigation upper∼lower limit: (70–55 %) θ FC , where θ FC represents field capacity] and five NaCl application rates [0 (C 0), 15 (C 1), 30 (C 2), 45 (C 3), and 60 (C 4) mmol L−1], respectively. All treatments were designed using a randomized complete block with three replications. The results indicated that DISC could significantly promote the physiology and growth of Panax notoginseng and improve yield, quality and economic benefits under micro-sprinkler irrigation and shaded conditions in 2018 and 2019. Compared with the D M C 0 and D L C 0 treatments, D L C 1 treatment significantly improved net photosynthetic rate (Pn), stomatal conductance (Gs), root (k r), shoot (k sh), and canopy (k c) hydraulic conductance of Panax notoginseng. The D L C 1 treatment significantly increased root length, surface area, average diameter, and volume of root of Panax notoginseng compared with the D M C 0 and D L C 0 treatments. The D L C 1 treatment significantly improved rood dry matter, yield, saponin content of Panax notoginseng , water use efficiency, and economic benefits by decreasing the incidence of root rot, but reverse results were observed in the D L C 2 , D L C 3 , and D L C 4 treatments. Therefore, this study suggested that deficit irrigation amount [ D L , (80–65 %) θ FC ] combined with NaCl concentration (C 1 , 15 mmol L−1) should be recommended as an appropriate agronomic management strategy to alleviate root rot and improve water use efficiency, saponin content, economic benefits of Panax notoginseng in the seasonally arid region of Southwest China. [Display omitted] • Deficit irrigation combined with sodium chloride (DISC): a strategy to improve Panax notoginseng production. • The DISC decreased root rot and improved physiological features of plant. • The DISC improved yield, quality, and economic benefits of Panax notoginseng. • The DISC [ D L , (80–65 %) θ FC and C 1 , (15 mmol L−1)] should be recommended to promote production of Panax notoginseng. [ABSTRACT FROM AUTHOR]