Bioefficacy, residue dynamics and dietary risk assessment of gibberellic acid in improving the potential yield of tomato (Solanum lycopersicum L.).

The increasing use of gibberellic acid (GA) to promote fruit growth and yield has necessitated research into its trace level determination and estimation in harvested product. The phytohormone has increased the tomato yield (tonne ha) up to 24.7% with uniform fruit shape, size colour and lustre. A fast, simple, high-throughput analytical method was standardised based on electrospray ionisation - liquid chromatography-tandem mass spectrometry (LC-MS/MS). The samples were extracted using acidified (1% formic acid) methanol. The method was validated as per the SANTE/12682/2019 guidelines. The limits of detection (LOD) and quantification (LOQ) were 0.01 and 0.05 mg kg. The average recoveries at LOQ and higher levels were in the range of 86-108% with relative standard deviation (RSD) < 20%. The validated method was successfully applied under field condition by following first-order kinetics with half-lives (T) 1.76 days (recommended dose) and 1.99 days (double dose). The estimated pre-harvest intervals (PHIs) were 6 days (recommended dose) and 8 days (double dose). Studies on dietary risk assessment concluded that even after spray of GA at recommended dose, the harvested produce (tomato) could be consumed safely.