Abstract

Extracts of the brown seaweeds (Sargassum myricocystum) red seaweed (Gracilaria edulis) and green seaweed (Caulerpa racemosa) have been used as a biostimulant to promote seedling emergence and vigour. The two different concentrations (1 and 5%) and soaking durations of (1:1 seed t solution ratio) were used. Results of the present study suggest that the sunflower seed soaked in 5% C. racemosa seaweed extract for 8 h performed significantly in all estimated characters (72% Germination; 15.95 cm Shoot length; 13.60 cm Root length; 0.399 OD Dehydrogenase activity; 0.277 dSm^-1 electrical conductivity and lowest abnormal seedlings production 3%) can be recommended as a mid storage seed treatment for improving the vigour and viability of aged seeds.

Key words: Seaweed extracts, sunflower seeds and vigour.