Variation in physiological traits, yield and secondary metabolites of jimsonweed (Datura stramonium L.) under different irrigation regimes and nutrition systems

Among various stresses, water-deficit stress is one of the major stress factors that limit crop yield. In order to study the effects of irrigation regimes and nutrition systems on some physiological characteristics, yield and its components, and two main alkaloids (atropine and scopolamine) of jimsonweed (Datura stramonium L.), experiments were conducted as a factorial based on randomized complete block design with three replications at research farm, agricultural faculty of Azarbaijan, Shahid Madani University, Tabriz-Iran in 2016-2017. Evaluated factors were selected as irrigation regimes (irrigation at the 55%, 35% and 15% of total available water capacity in the soil) and nutrition systems (poultry manure, vermicompost, and nitrogen fertilizer). Results indicated that the lowest leaf area index, relative water content, membrane stability index, chlorophyll a, b, total chlorophyll and carotenoids, and maximum praline and soluble sugars obtained from severe water-deficit stress condition in the soil. Maximum leaf area index, membrane stability index, chlorophyll a, b, and carotenoids were related to poultry manure and vermicompost application as soil amendments. In contrast, maximum praline and soluble sugars were related to nitrogen fertilizer. Interaction effects revealed that the relative water content, chlorophyll It, and carotenoids reduced, praline, and soluble sugars increased more than other treatments at the 15% of available water capacity by application of nitrogen fertilizer. Atropine and scopolamine contents increased by increasing severity of water-deficit stress. The highest atropine content measured in leaves was related to both organic fertilizers, but maximum scopolamine produced using vermicompost as a nutrition system. In general, organic fertilizers, especially vermicompost could diminish water-deficit stress adverse effects, and improved alkaloids content, yield and its components in jimsonweed plants compared with nitrogen fertilizer.