~ 278 ~ International Journal of Chemical Studies 2017; 5(6): 278-283 P-ISSN: 2349–8528 E-ISSN: 2321–4902 IJCS 2017; 5(6): 278-283 © 2017 IJCS Received: 21-09-2017 Accepted: 22-10-2017 Sandeep Nigania Department of Soil Science and Agricultural Chemistry, College of Agriculture, Swami Keshwanand Rajasthan Agricultural University, Bikaner, Rajasthan, India Yogesh Sharma Department of Soil Science and Agricultural Chemistry, College of Agriculture, Swami Keshwanand Rajasthan Agricultural University, Bikaner, Rajasthan, India Bablesh Kumar Department of Soil Science and Agricultural Chemistry, College of Agriculture, Swami Keshwanand Rajasthan Agricultural University, Bikaner, Rajasthan, India Correspondence Sandeep Nigania Department of Soil Science and Agricultural Chemistry, College of Agriculture, Swami Keshwanand Rajasthan Agricultural University, Bikaner, Rajasthan, India Role of humic acid and salicylic acid on quality parameters and K/Na ratio of Groundnut ( Arachis hypogaea L.) under salt and water stress Sandeep Nigania, Yogesh Sharma and Bablesh Kumar Abstract A field experiment was conducted during kharif 2015-16 to study the response of groundnut to humic acid and salicylic acid under salt and water stress conditions. Results revealed that application of saline water (4.0 dS m -1 ) and water deficit irrigation (0.8 ETc) significantly decreased the quality parameters of groundnut such as oil, protein and shelling percent and due to saline water application there was increase in Na ion concentration in plant resulted in decreased K/Na ratio. Application of both humic acid and salicylic acid significantly increased the quality parameters and K/Na ratio in plant. The combined effect of saline water (4.0 dS m -1 ) with humic acid (1500 ppm) application showed that humic acid alleviate the detrimental effect of saline water by an increasement in such quality parameters and K/Na ratio. The combined effect of humic acid and salicylic acid (HA+SA) was also found significant and recorded maximum protein content (26 %) and K/Na ratio (6.01). Application of salicylic acid (1.5 mM) also significantly increased the K/Na ratio in salt stressed conditioned and maintain the ionic balance in cell sap. Keywords: ECiw, dS m -1 , Shelling, K/Na ratio Introduction Salt and water stress have been found to disrupt several physiological processes leading to reduction in quality parameters, ionic balance and yield. Salt stress induces ionic stress and osmotic stress in plant cells. A direct results of these primary effects is the enhanced accumulation of reactive oxygen species (ROS) that are harmful to plant cells at high concentration (Parida and Das, 2005) [11] . High concentrations of Na + in the soil also cause the disruption of intracellular ion homeostasis, membrane dysfunction and inhibition of metabolic activity, resulting in inhibition of growth and yield (Hasegawa et al., 2000) [6] . Yeilaghi et al. (2012) [17] examined the effects of salinity stress on seed oil content and fatty acid composition in various genotypes of safflower (Carthamus tinctorius L.). The major functional groups of humic acids include carboxyl, phenolic hydroxyl, alcoholic hydroxyl, ketone etc. (Russo and Berlyn 1990) [15] . The mechanism of humic acid activity in promoting the plant growth is not completely known, but several explanations have been proposed by researchers such as increasing cell membrane permeability, oxygen uptake, respiration and photosynthesis, phosphate uptake, and root cell elongation (Vaughan 1974 and Russo and Berlyn 1990) [16, 15] . The malondialdehyde (MDA), lipid peroxidation and H 2 O 2 contents reduce significantly after HA treatments (Kesba and El-Beltagi, 2012) [7] . Salicylic acid (SA) is a naturally occurring plant hormone, is an important signal molecule known to have diverse effects on biotic and abiotic stress tolerance. The positive effects of SA on groundnut plant have also been reported under drought stress (Rady et al. 2015) [12] . SA usually improves plant growth under salinity due to decreased concentrations of Na, Cl and H 2 O 2 in plants, decreased electrolyte leakage, increased N and Ca contents and increased antioxidant enzyme activity (Khan et al. 2010) [8] . El-Hak et al. (2012) [5] conducted a field experiment to study the beneficial effect of foliar spray of salicylic acid (200 ppm) on shelling per cent, protein content and yield characteristics of pea (Pisum sativum L.). The results showed the significant increase in shelling per cent and protein content in both the successive season of 2009/2010 and 2010/2011.