Today, algae extracts are used as biological stimulants. These extracts can contribute to sustainable agriculture by increasing the rate of seed germination and promoting plant growth through improving soil fertility and increasing yield. In this research, the effect of Ulva sp algae extract. and Nostoc sp. It was investigated on the photosynthetic pigments of corn plant. 1 gram of Ulva sp algae powder. It was extracted in 100 ml of distilled water and a 10% dilution was prepared. The amount of 0.5 grams of algae Nostoc sp. It was also extracted in 100 ml of distilled water and 50 and 100% dilutions were prepared. The resulting extracts were added to the soil weekly and after 4 weeks, the amount of photosynthetic pigments of the resulting plants was measured. The results showed that the amount of chlorophyll a in the concentration of 50 and 100% of Nostoc sp. and 10% of Ulva sp. increased by 28, 58 and 13% respectively compared to the control. Chlorophyll b in the concentration of 50 and 100% of Nostoc sp. and 10% of Ulva sp. It had 70, 116 and 40% growth compared to the control, respectively. Carotenoids in concentrations of 50 and 100% Nostoc sp. and 10% Ulva sp.It had 60, 80 and 40% growth compared to the control, respectively. The results show that the blue green algae extract Nostoc sp. and green algae Ulva sp. As a biological stimulant, it has a positive effect on increasing the photosynthetic pigments of the corn plant.
