Growth and Macronutrients Status of Mung Bean [Vigna radiata (L.) Wilczek] Grown under Lead (Pb) Stress and Exposed to Foliar Spray of Indole Acetic Acid (IAA)

Abstract

Background: Growth and nutritional status of plant are affected adversely by heavy metals while improved by plant growth regulators. The experiment was aimed to explore the ameliorative potential of indole acetic acid (IAA) for toxicity of Pb. Methods: Two varieties i.e., M-8 and MN-92 of mung bean were grown in pots arranged under complete randomization. Fifteen days after germination, Pb was added @ 10 and 20 mg/kg soil as solutions of PbNO3. Indole acetic acid @100.0 mM was sprayed twice at 15 and 30 days of age. Stem length, root length, leaf area and nutrient ions were recorded at physiological maturity. Three replicates from each treatment were evaluated. Result: The alleviation role of IAA for stem length was recorded as 21.46 and 26.14% for low and high lead stress. The root length was compensated to 34.78 and 31.40% for the respective low and high lead toxicity. Leaf area was affected as 18.11 and 17.32% by IAA. Similarly, Nitrogen contents were nullified to the extents of 15.34 and 8.13%. Phosphorus contents were changed as 11.62 and 4.65% while potassium contents were as 10.14 and 19.36%. The rectifying potential of IAA for leaf biomasses were as 7.64 and 7.43%.