Response of Aloe vera seedlings to different levels of nitrogen

In this study, a greenhouse study was conducted to investigate the growth of Aloe vera with different content of nitrogen fertilizers. Treatments consisted of 0, 0.15, 0.29, 0.43, 0.57 and 0.71 g/pot ammonium nitrate and 0, 0.11, 0.22, 0.33, 0.43, 0.53 g/pot urea. Then the effects of nitrogen fertilizers on fresh weight, photosynthetic pigments and proline content were studied. The results indicated that fresh weight was increased in response to application of 0.29, 0.43 and 0.57 g/pot ammonium nitrate and 0.22 urea as compared to the control. Chlorophyll a content was increased at rate of 0.29 g ammonium nitrate/pot. Chlorophyll b and carotenoid contents were increased at rate of 0.15, 0.29, 0.43 and 0.57 g ammonium nitrate/pot. Chlorophyll a and b contents did not show any differences in response to application of urea, but carotenoid content increased at rate of 0.53 g urea/pot as compared to the control and 0.11 g urea/pot. Proline content was same as control under ammonium nitrate, but increased with urea, significantly. It was calculated that 300 kg/ha ammonium nitrate and 200 kg/ha urea were sufficient for optimum growth and leaf production of A. vera seedlings. These amounts with respect to nitrogen percentages of ammonium nitrate (35%) and urea (46%) are approximately equal to 100 kg/ha nitrogen.