Sunflower (Helianthus annuus L.) is one of the
most important oil seed crops in Iran. It is a short
duration crop (90–110 days), which can be grown
twice per year. It is fully suited to the Iranian
cropping system and can be grown without
causing displacement of any major crop.
the major obstacles to high yield and production
is the lack of synchronised crop establishment in
sunflower due to poor weather and soil conditions
(Mwale et al. 2003). The seeds are occasionally
sown in seedbeds with unfavourable moisture
because of the lack of rainfall at sowing time
(Angadi and Entz 2002), and this results in poor
and unsynchronised seedling emergence (Mwale
et al. 2003). Soil salinity affects the germination
of seeds either by creating an external osmotic
potential preventing water uptake by seeds,
or through the toxic effects of Na+ and Cl– ions
on the germination of seeds (Khajeh-Hosseini
et al. 2003).