Influence of salicylic acid and potassium nitrate on plant height and flowering time of groundnut (Arachis hypogaea L.) under varying salinity and drought-induced stresses

Abstract

This study was conducted to examine the effects of Salicylic acid (SA) and Potassium nitrate (KNO3) on plant height and flowering time of groundnut (Arachis hypogaea L.) under induced stresses of salinity, drought and combined salinity and drought. Three watering regimes namely; normal, moderate and severe were used. For salinity stress, 50 mM NaCl, 100 mM NaCl, 150 mM NaCl and combination of water and salinity regimes were used. 50 μm KNO3 and 50 μm SA were separately applied to plants under water, salinity and combined water and salinity stresses. The mean plant height at 100 mM salt concentration were 42.29 cm for KNO3, 42.27 cm for SA, compared with 40.98 cm for control (F = 2.73; P ≤ 0.008). In combined severe watering and 150 mM NaCl treatment, flowering time was 57 DAP (days after planting) compared to 34 DAP in control plants. When KNO3 and SA were applied to severe watering and 150 mM NaCl combined stress induced plants, flowering time was 51 DAP and 53 DAP for KNO3 and SA treated plants respectively. In conclusion, the exogenous application of plant growth regulators such as SA and KNO3 reduce impact of water stress on groundnut and effectively improve yield.