Seed germination and early seedling growth are the most important stages of plant development. Fast seed germination, stand establishment and uniform field emergence are critical factors to crop production and are essential to achieve ptimum performance. Controlled imbibition of seed followed by dehydration could be applied for reducing the time from sowing to seedling establishment and improving germination rate. In present study the effect of pre-germination hydration of sunflower seeds in solutions containing different concentrations of nano-silica (0, 0.2, 0.4, 0.6, 0.8, 1 and 1.2 mM for 8 h) on germination characteristics were investigated. Seed pre- sowing treatment in low concentration of silica nanoparticles (0.2 and 0.4 mM) reduced days to 50% germination and mean germination time and improved germination energy, root length, mean daily germination, germination rate, seedling vigor index, promptness index and final germination percentage. The results of the present experiment agreed with the conclusion that pre-sowing seed treatments with low concentration of nanosilica had favourable effect on sunflower seed germination and seedling early growth. The findings are noteworthy in terms of utilization of suitable concentration nanoparticles as an efficient seed vigour enhancement treatment to improve seedling growth under environmental conditions.
