Evaluation the effect of red seaweed extract on growth and physiological indices of three genotypes of squirting cucumber (Ecaballium elaterium L.)

Today, seaweed biofertilizers are widely used in the world to increase plant growth and yield. In order to study the effect of red seaweed on growth and physiological traits of squiring cucumber, this research was conducted in split plot experiment based on randomized complete blocks design with three replications during 2019. Experimental treatments consisted of three squirting cucumber genus ((I) Iranian, (S) Spanish and (B) British) as the main plot and three levels of foliar application of red seaweed extract including Acanthofora (A. spicifera) seaweed extract (A, 2L ha-1), Gracylaria (G. corticata) seaweed extract (G: 2 L ha-1) and the combined seaweed extract from the 1:1 ratio mixture of both red seaweed (AG: 2 L ha) and spraying with distilled water (control)  as a sub plot. The results showed that all three levels of seaweed extract increased the growth and physiological indices in all three genotypes of squirting cucumber. The highest plant height (55.88 cm), number of lateral branches (12.94) and leaf area (312.22 cm2) was obtained in Iranian genotype with application of combined seaweed extract. The maximum total chlorophyll content was observed in Spanish (26.15 mg.g-1FW) and Iranian (25 mg.g-1FW) genotypes, respectively with application of combined seaweed extract. Also, the highest total alkaloids content and antioxidant capacity was obtained in British genotype. At all, foliar spray of combined two seaweeds extract had the highest effect on growth, fruit number and fruit biochemical indices. Therefore, the application of combined red seaweed extract can be proposed to improve growth and biochemical indices of squirting cucumber.