The capability of microalgae had been studied for a long time; however, some basics of using microalgae as a biostimulant are still in question. In the present work, experiments were conducted to reply to questions such as (a) how does the application time affect the effects of microalgae treatments and (b) does variety or genetic variation cause differences in the effect of microalgae biomass application on the plants? The different times of application had different weightage on different parameters; however, when applied at the early reproductive stage the yield as well as the nitrogen % in grain was significantly affected. As per the comparison, the result suggested that varietal differences had negligible differences in biological yield, hexose content, and total phenol content. Furthermore, microalgae biomass treatment irrespective of the strain species or genus influences the biological photosynthate accumulation and nitrogen uptake or in short, the efficiency of uptake. Finally, the metabolomic analyses suggested the influence of the microalgae strains on the biochemical composition of the plants.