Effect of certain nitrogen fertilizers on growth, photosynthetic pigments, carbohydrates and lipid contents in Cucumis melo var aegyptiacus during germination and seedling growth

ABSTRACT

Application of nitrogen either NO3- or NH4NO3 at 102 and 101 ppm or NH4+ at 101 ppm to Cucumis melo plants highly significantly increased their rate of growth [expressed a mean length of shoot and root mean fresh and dry weights of seedlings and mean number of lateral roots] than those of the untreated seedlings. Increasing the N-concentration to 103 ppm, these growth criteria were either slightly decreased due to both NO3- and NH4+ treatments or increased as a result of NH4NO3 application. As a consequence to the different nitrogen forms used, the total pigments, chlorophyll [a], chlorophyll [b] and carotenoids were highly elevated above those of the control levels, although NO3- at 103 ppm and each of NH4+ and NH4NO3 at 103 and 102 ppm decreased the chlorophyll [b] contents