Chlorophyll fluorescence has been noted to be one of the most widely used tools in assessing photosynthetic performance and stress in plants. The use of chlorophyll fluorescence in crop monitoring during the vegetative stage of development might be critical. Therefore, the study investigated the effect of two types of fertilizers nutrient (organic poultry manure based product (Bio-Fer Natur) and N fertilizer (Pétisó) on the chlorophyll fluorescence parameter of three green pea genotypesthe to determine the benefits of organic and inorganic fertilizers during the vegetation growth stage of green pea, to assess which Chlorophyll fluorescence parameter is most reliable in quantifying photosynthesis in plants grown in amended soil, and to assess the potential use of chlorophyll fluorometer in screening plant genotypes, in small pots experiment at the greenhouse condition, of Institute of Water and Environmental Management, Faculty of Agriculture, Food Science and Environment, University of Debrecen, Hungary, from April 29 to June 22, 2022. In comparison to the C treatment, the application of SZ and M had a good effect on the growth parameters (shoot, root, and wet biomass) of green pea's DEB genotype. The chlorophyll fluorescence characteristics (Fv/Fm and Fv/F0) varied insignificantly across treatments SZ, M, and C. Among green pea genotypes, (Fv/Fm and Fv/F0) had a beneficial impact. The DEB variety yielded the best results for each treatment, followed by SG and Kiss. Overall, the study suggests that the application of Bio-Fer Natur can provide comparable growth and yield benefits to N fertilizer (Pétisó), while also improving photosynthetic performance of green pea genotypes.