1Regional Research Station, Tamil Nadu Agricultural University, Paiyur, Krishnagiri, India
2Department of Crop Physiology, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India
3Anbil Dharmalingam Agricultural College and Research Institute, Trichy, Tamil Nadu, India
*Corresponding author: sivatnau14@gmail.com (ORCID ID: 0000-0001-6941-9940)
Online published on 22 March, 2019.
An experiment was conducted to study the effect of plant growth regulators like jasmonic acid (50 μM), brassinolide (0.5 ppm), salicylic acid (100 ppm), ascorbic acid (100 ppm), gibberellic acid (10 ppm), benzyl amino purine (5 ppm) and nutrient consortium (K2SO4-0.5% + FeSO4-0.5%) + Borax-0.3%) and 1% TNAU pulse wonder on blackgram (Vigna mungo L.) variety TNAU Blackgram CO 6 under salinity condition. The salinity was imposed by 125 mM NaCl concentration in pot culture. Plant growth regulators and nutrient consortium were used as foliar spray at 20 and 40 days after sowing except jasmonic acid, which used as seed soaking. Under salinity stress, root volume, leaf area, specific leaf weight, net assimilation rate and yield were significantly reduced compared to normal condition. Among the treatments, brassinolide showed its supremacy on higher leaf area (149.13 cm2 plant−1), specific leaf weight (0.41 mg cm−2) and super oxide dismutase activity (325 Units mg−1 protein) followed by salicylic acid and TNAU pulse wonder. However highest root volume of 3.5 cc was recorded by TNAU pulse wonder. Salicylic acid registered highest net assimilation rate of 0.398 mg cm−2 d−1 followed by brassinolide (0.396 mg cm−2 d−1). The minimum Na+/K+ ratio (0.325) was observed in brassinolide followed by salicylic acid (0.355) which is on par with nutrient mixture (0.357) and TNAU pulse wonder (0.362). Among the plant growth regulators and nutrients, brassinolide recorded the maximum grain yield of 8.85 g plant−1 followed the salicylic acid (8.72 g) which is on par with TNAU Pulse Wonder (8.60 g).
Root volume and leaf area were reduced up to 46.8% and 14.07% respectively by salinity in blackgram
Foliar application of 0.5 ppm brassinolide significantly increased the SOD activity by 13.6% compared to control.
Exogenous application of plant growth regulators and nutrients reduces the sodium potassium ratio in blackgram under salt stress condition.
Higher grain yield was recorded by foliar spray of 0.5 ppm brassinolide treatment which is on par with salicylic acid and TNAU pulse wonder over control
Brassinolide, TNAU pulse wonder, blackgram, SOD, leaf area, SLW, Na+/K+, Yield
