Bio-Invigoration of Rhizobacteria Supplemented with Exogenous Salicylic Acid and Glycine Betaine Enhanced Drought Tolerance in Sunflower

Water deficit drastically hamper productivity of sunflower. In this study, the role of bio-invigoration of ACC deaminase rhizobacteria supplemented with chemicals i.e., glycine betaine and salicylic acid in alleviating negative effect of drought stress in sunflower was investigated. The inoculants of rhizobacteria i.e., KS7 and KS42 were applied as seed coating. While plants were foliar sprayed with 0.724 mM salicylic acid and 100 mM glycine betaine solutions at vegetative and flowering stage. Soil moisture was monitored with Time Domain Reflectometer (TDR) on weekly basis. Data on plant water relations, leaf free proline, leaf glycine betaine and total soluble sugars were recorded at flowering stage, while yield was recorded at maturity stage. Maximum improvement in selected plant traits and water use efficiency was caused by treatments where seed inoculation of KS42 and KS7 was supplemented with foliar spray GB or KS42 was combined with SA or sole inoculation of KS42 was performed. This novel approach of using biological and chemical means together may be recommended for field areas, where water deficit conditions limit sunflower production. (C) 2020 Friends Science Publishers