Compatible solutes control cell osmotic balance and compatible the cells' metabolism whereas nano-particles have been introduced to increase crop production with inadequate knowledge. This investigation is done to evaluate the effects of application of salicylic acid, glycine betaine and nano titanium dioxide on sunflower. Measured traits were plant height (PH), leaf length (LL), chlorophyll content (CHL), number of seeds per head (NSH), 1000-seed weight (TSW), day to maturity (DM), husk percentage (HP), kernel weight (KW), percentage of empty achenes (PEA), head number per plant (HNP), grain yield (GY) and oil percent (OIL). Results indicated that the first two principal components accounted 92% of total variation of the treatment by trait (T×T) interaction and were used to generate a T×T biplot. All treatments were identified as the vertex treatments in polygon of TT biplot and the nano titanium dioxide treatment had high values for all traits expect PEA, HP and TSW. The nano titanium dioxide was identified as ideal treatment and GY and HNP were identified as ideal traits. The positive correlations between HNP and GY, and between OIL and KW; and near zero correlations between TSW and HP, and between TSW with DM as showed. Application of compatible organic solutes (glycine betaine and salicylic acid) had not any considerable improvement on traits while application of nano-titanium dioxide indicated considerably enhanced the yield and most traits of sunflower.
