investigating the effect of density and cultivar on onion seedling production in a floating culture system

This research, conducted in 2023, identifies onion seedling  production key challenges and explores two onion cultivars (ramhormozi and primavera) and four density levels {1, 2, 6, and 12 plants in a cell} in a factorial arrangement with three replications. the study focuses on current agricultural practices, the effectiveness of existing methods and the agricultural factors influencing onion seedling farming such as two treatments cultivar and density. a analysis of variance using spss software version 21 revealed that the interaction between cultivar and density had a significant impact on most of the traits examined. each trait showed a different response to these two treatments. the highest and lowest leaf area index were observed in the primavera cultivar at 6 plants (9.4 m²) and 1 plant (0.33 m²), respectively. so that the quantitative changes are 28 fold. the highest fresh aerial height weight was recorded in the ramhormozi cultivar at 1 plant (7.6 g), while the lowest was in primavera at 12 plants (1.7 g). the quantitative changes  in fresh aerial weight are 4.47 fold. the primavera cultivar at 1 plant (1.66 mg/g) and 12 plants (0.65 mg/g) had the highest and lowest total chlorophyll content, respectively. the quantitative changes in total chlorophyll are 2.5 fold. also, the results of the correlation analysis among the studied traits in this experiment revealed significant correlations between the morpho-physiological and biochemical traits. the research demonstrated that hydroponic onion cultivation with hoagland nutrient solution under two treatments of planting density and cultivar had a significant effect on the growth and functional characteristics of onion seedlings. in general, it can be concluded that marketable and healthy onion seedlings are produced at high densities and in different cultivars using the flotation system. this cultivation method can, as an efficient production system, compensate for the limitations of onion seedling production in uncultivable lands.