Abstract
The impact of three auxins indole-3-acetic acid (IAA), 4-chloroindole-3-acetic acid (4-Cl-IAA), and indole-3-butyric acid (IBA) on nitrogen metabolism were investigated in chickpea (Cicer arietinum L.). Plants were raised from seeds soaked in water (control), 10-8 M of IAA, IBA, or 4-Cl-IAA, for 12 hours and were assessed for different parameters at 60 days after sowing. Observations showed that auxins, irrespective of the analogue significantly increased the nodulation, leghemoglobin content, nodule nitrogen content and the enzymes of nitrogen assimilation. Of the three auxins, 4-Cl-IAA was the most effective in increasing these parameters. The increase in seed yield was 27% higher than the water soaked control. The response to auxins followed the trend 4-Cl-IAA IAA IBA control. It may be concluded from the present investigation that auxins, irrespective of the type, significantly improved the nitrogen metabolism, photosynthesis and yield of the chickpea. Of three auxins used, 4-Cl-IAA generated the best response.