Nano fertilizers are new generation of the synthetic fertilizers which contain readily available nutrients in nano scale range. To evaluate the effects of foliar spray of nano-iron and nano- zinc as well as nano titanium dioxide on grain yield and its components in barley under supplemental irrigation conditions, a field experiment was carried out in the semi-arid highland region of Maragheh, Iran. The treatments included micronutrients (Cont: control Nan-Fe: press nano chelate, NanoZn: zinc nano chelate,) and foliar application of nano-titanium, Cont: (without application), and Nano-Ti: 2000 ppm. PH (plant tallness), SD (stem breadth), NGS (number of grains per spike), PL (peduncle length), SL (spike length), TGW (thousand grain weight), DA (day to anthesis) and GY (grain abdicate) were measured. The primary principal component clarified 73% of total variation whereas the second principal component clarified 15% of observed variability. We found positive association between TGW (thousand grain weight) and DA (day to anthesis), between SD (stem distance across) and NGS (number of grains per spike), and between NGS (number of grains per spike) and GY (grain yield). Although foliar fertilization with nano-fertilizer is more effective, it may be due to their high mobility in the vascular transport system of plants, the properties of nanoparticles are highly dependent on the size, shape and surface functionalization, so further studies in the vascular transport system. of plants is needed. induced cellular and molecular changes after foliar application of micronutrient nano-fertilizer.
