Safflower is one of important crop in semi-arid regions of the world, where the precipitations are limited. In order to investigate the effect of foliar spray of nano-silicon dioxide (10 and 20 mM) and nano titanium dioxide (25 and 50 mM) and water-deficit stress (irrigation after 110 mm evaporation) on growth parameters and yield components of spring safflower a field experiment was carried out at the highland semi-arid region, in, North West of Iran. Water deficit stress significantly reduced morpho-physiological traits such as ground cover, canopy width, leaf fresh mass, leaf are and plant height) as well as yield components (e.g. capitulum diameter, seed mass and seed number per capitulum). However, the plants grown under water deficit condition showed the higher harvest index than well irrigated plants. Comparison of the foliar treatments showed that the both nano-particles (silicon and titanium) improved the plant growth and yield components over the control. However, the effect of nanosilicon was more prominent than titanium. The highest amount of seed oil was recorded under well irrigated condition (irrigation after 60 mm evaporation) with foliar application of nano-titanium. The percentage of palmitic acid, arachidic acid and myristic acid in seed increased by nano-titanium application. Altogether, principal component analysis indicated that spray of 10 mM nano silicon dioxide was best foliar treatments under all moisture regimes.Key words: safflower; agronomic traits; foliar spraying; nanoparticles; principal component analysis; semi-arid region IZVLEČEK UČINKI SILICIJA IN TITANA NA RAST ŽAFRANIKE (Carthamus tinctorius L.) V RAZMERAH POMANKANJA VODEŽafranika je pomembna poljščina v semiaridnih območjih, kjer so padavine omejene. Z namenom ugotavljanja učinkov pršenja listov z nano-silicijevim (10 in 20 mM) in nano titanovim dioksidom (25 in 50 mM) ter stresa zaradi vodnega deficita (namakanje po 110 mm evaporacije) na rastne parametre in komponente pridelka pomladanske žafranike je bil izveden poljski poskus na višinskem semiaridnem območju severno zahodnega Irana. Vodni deficit je značilno zmanjšal morfološko-fiziološke lastnosti (pokritost tal, širino krošnje, svežo maso listov, listno površino in višino rastlin) kot tudi komponente pridelka (premer koška, maso semen in število semen na košek). Kljub temu so imele rastline, ki so rastle v razmerah pomanjkanja vode večji žetveni indeks kot dobro namakane. Primerjava foliarnih obravnavanj je pokazala, da so oboji nano delci (silicijevi in titanovi) izboljšali rast rastlin in komponente pridelka v primerjavi s kontrolo. Učinek silicijevih nano delcev je bil bolj izražen kot titanovih. Največja vsebnost olja v semenih je bila v dobro namakanih rastlinah (namakanje po 60 mm evaporacije) s foliarno dodajanimi nano delci titana. Odstotki palmitinske, arahidonske in miristične kisline v semenih so se povečali po uporabi nano titanovih delcev. Analiza glavnih komponent je pokazala, da je bilo pršenje z 10 mM nano silicijeva dioksida najboljše foliarno...