Improving physiological performance and productivity of oilseed rape under drought stress by foliar application of Zn and Mg nanoparticles

A field experiment was laid out as a split-plot design based on the randomized complete block design with three replications in 2018, to assess the responses of oilseed rape (Brassica napus L.) plants to the foliar treatment of nanoparticles (ZnO and MgO) under different watering levels (I1, I2, I3, I4: Irrigation after 70, 100, 130, and 160 mm evaporation as normal irrigation, and mild, moderate, and severe stresses, respectively). Water shortage increased leaf temperature and decreased leaf water content, membrane stability, chlorophyll content, and plant biomass, which resulted in the reduction of the grain yield per unit area. Foliar application of nanoparticles enhanced grain and oil yields of oilseed rape by reducing some detrimental impacts of water limitation on leaf temperature, chlorophyll content, membrane stability, plant height, plant biomass, grains per plant, and 1000-grain weight. Therefore, foliar spray of these nanoparticles could be a superior treatment for alleviating some of the adverse effects of drought stress on the physiology and productivity of oilseed rape plants in the field.