The most of the cultivated crops are often facing with drought stress and application of some nanoparticles and growth regulators alleviate the adverse effects of stress. Present study is performed to evaluate the effects of foliar application of salicylic acid (S-A), glycine betaine (G-B), ascorbic acid (A-A), nano-silica (nano-SiO2) and nano titanium dioxide (nano-TiO2) on yield and yield component of sunflower. Chlorophyll content, leaf length, leaf width, days to 50% flowering, day to maturity, plant height, husk percentage, number of seeds per head, head number per plant, percentage of empty achenes, 1000-seed weight, kernel weight, grain length, straw yield, harvest index, grain yield and oil percent were measured. Results showed that the first two principal components were used to create a two-dimensional treatment by trait biplot that accounted percentages of 49% and 19% respectively of sums of squares of the TT interaction. The vertex treatments were A-A, G-B, Nano-TiO2 and control which Nano-Ti2 treatment indicated high performance in chlorophyll content, day to maturity, number of seeds per head, head number per plant, kernel weight, grain length, straw yield, harvest index, grain yield and oil percent. Treatments suitable for obtaining of high seed yield were identified in the vector-view function of TT biplot and displayed nano-silica and nano titanium dioxide as the best treatmentS suitable for obtaining of high seed yield. In short, nano-fertilizer could increase crop yields and improve the fertilizer efficiency.
