Nanofertilizers are new products which contain readily available nutrients in the nanoscale range and are preferred largely due to their efficiency. To investigate the effects of micronutrient nanofertilizers (iron and zinc) as F factor and nano-titanium dioxide (nano-TiO2) solution as n factor on yield performance and some morphologic traits of barley, a field experiment was carried out with treating with chelated nanoscale zinc oxide (nano-ZnO) and ferric oxide (nano-Fe2O3) suspensions during three phonological stages. The treatment combination by trait (TT) biplot was used for two-way dataset as various treatment combinations (Fn) with multiple traits. The GT biplot explained 83% of the total variation of the standardized data. The polygon view of TT showed five vertex treatment combinations as F1n1, F1n2, F2n2, F3n1, and F3n2. Therefore, it seems that F3n1 treatment combination had the highest values for all of the days to maturity, grain yield, straw yield, harvest index, spike length, number of fertile tillers, and grain weight per plant traits. The most prominent relations of tester-view biplot were: a strong positive association between days to maturity and straw yield and among grain yield, harvest index and spike length, while there was a near zero correlation of the number of tillers per plants with days to maturity and straw yield. It can be concluded that TiO2 nanoparticles and nano-micronutrient fertilizers (iron nano-chelate and zinc nano-chelate) could increase yield and yield components of barley. Our findings suggest that the foliar application of nanoparticles resulted in sustainable and high crop production, and among six treatment combinations, F3n2 (zinc nano-chelate with 2000 ppm nano-TiO2) indicated the best performance for most of the measured traits of barley.
