Effect of salinity tolerance in yield performance of guinea grass (Megathyrsus maximus) genotypes

Abstract

Excess salts in soil negatively impact the growth and development of plants. These types of land under the salinity impact could be changed for pasture production or fodder cultivation to improve animal husbandry when croppingis impossible due to higher salinity levels. Guinea grass performs well in cut-and-carry systems and can be used to make hayand silage. The research study was conducted in MARS, UAS Dharwad to evaluate the physiological mechanisms ofsalinity tolerance in Guinea grass (Megathyrsus maximus Jacq.), its recovery from salinity stress and tolerance contributesto its yield performance. The genotypes were studied in artificially made saline soil. Artificial saline soil was prepared bya combination of salts of NaCl, Na2SO4, MgCl2 and CaSO4 in the salt ratio: 13:7:1:2, respectively. Varieties BG-1, BG-4,DGG-1, and CO-1 were planted in control and artificially created in 12 ECe soils. After salinity was imposed, threeharvests were taken. DGG 1 recorded the highest fresh biomass yield in this study, followed by BG-4, where CO-1 and BG1 recorded the lowest biomass yield. Leaf succulence was highest in DGG1 and lowest in BG 4. More leaf succulence couldameliorate the ionic and osmotic stress effects of high salinity treatment and provide long-term storage to facilitateimproved reproductive capacity under salinity stress conditions. BG4 recorded the lowest tissue tolerance because most ofthe salts are excreted through the micro hairs of leaves in this genotype. DGG1 has the highest leaf-to-stem ratio, whichresults in a higher number of leaves and leaf area. Membrane stability was increased at 45 days in the subsequent harvestin all genotypes. The increased tissue tolerance combined with increased membrane stability and more number of leaves inDGG-1 facilitated the recovery and increased biomass in DGG 1.