Investigation of green and brown macroalgae’s extract on some physiological parameters of basil (Ocimum basilicum L.)

Abstract One way to reduce the use of chemical fertilizers without harming plant nutrition and increase the absorption of nutrients in crops is to use biostimulants. Seaweed extracts is one of the plant biostimulants that is used in agricultural systems because of their potential for improving nutrient use efficiency, resistance to stressors, and product quality. In this study, the effects of aqueous extract of a green  macroalgae (Ulva flexuosa) and a brown macroalgae (padina) at four levels (dilutions 5, 10, 20 and 40%) as well as NPK chemical fertilizer at one level (concentration 0/625 mg/ml) on the growth of basil (Ocimum basilicum L.) was examined for 45 days. The results showed that the effect of brown algae extract on germination was more significant while 5% dilution of green algae increased plant root length. Treatment with both green and brown macroalgae extracts improved biochemical parameters. The highest amount of chlorophyll, carotenoids and anthocyanins was observed in dilution of 20% and the highest amount of flavonoids, phenol and reducing power was observed in 10% dilution of brown macroalgae extract.