Abstract: With pot experiment, this paper studied the effects of urea amended with dicyandiamide (D-U), 3,5-dimethylpyrazole (DMP-U), and dicyandiamide plus hydroquinone (H-D-U) on the growth of celery and its quality. The results showed that applying test urea fertilizers could enhance the aboveground biomass and its proportion to total biomass, decrease the nitrate content of leaf and stem, while increase their vitamin C, amino acid, and crude protein contents. H-D-U had the best effect in decreasing the nitrate accumulation in celery tissues.

Key words: Photosynthesis, Transpiration, Stomatal resistance, Environmental factors, Correlation