Controlled trial demonstrates foliar potassium nitrate mitigates growth reduction and cell damage in drought-stressed canola, indicating an effective agronomic strategy.
Key Points
To evaluate the efficacy of various foliar-applied biostimulants and nutrients in improving the drought tolerance, physiological traits, and growth of canola (Brassica napus L.).
Canola plants were grown under control (80% water holding capacity) and drought (50%) conditions in a completely randomized design with 6 replicates.
Foliar treatments of sodium silicate, potassium silicate, melatonin, ascorbic acid, salicylic acid, potassium nitrate (KNO3), and zinc sulfate were applied three times at the three-leaf stage.
Morphological parameters, stomata properties, and physiological indicators (chlorophyll content, leaf temperature, relative water content, and electrolyte leakage) were assessed using multivariate analyses.
Drought stress reduced plant fresh weight by 35% and leaf area by 25% while increasing stomata number and electrolyte leakage from 11.2% in control plants to 25.7% in drought-stressed plants.
Foliar applications of KNO3 effectively alleviated drought-induced damage by regulating relative water content, preserving chlorophyll content, and reducing electrolyte leakage.