Effect of Maleic Hydrazide Foliar Application on Biochemical Parameters and Phytohormonal Variations in Groundnut (cv. Dh 86)

This study assessed the impact of varying concentrations of maleic hydrazide (MH) on seed biochemical parameters in groundnut. Where increasing MH concentrations resulted with least total dehydrogenase activity (0.505 OD value at A480) and electrical conductivity (200 µS cm⁻¹), and increased phenol content (3.48 mg/g) at foliar spray of MH @ 3000 ppm over the control (0.822 OD value at A480, 257 µS cm⁻¹, 2.80 mg/g) respectively. Further this study examines the impact of MH foliar spray at 3000 ppm, unsprayed control and a dormant check (Dh 8) on groundnut seed phytohormones, comparing results to an unsprayed control. Abscisic acid (ABA) levels increased from 15.6 ng/g in unsprayed control to 45.96 ng/g in MH treated seeds and 74.58 ng/g in Dh 8, promoting dormancy. Gibberellins (GA3) reduced by 98.7% in MH treated seeds (0.88 ng/g) and by 99.2% in Dh 8 (0.54 ng/g). Auxins (IAA) decreased 86.8% in MH treated seeds (1.15 ng/g) and 22.9% in Dh 8 (6.70 ng/g) relative to unsprayed control (8.71 ng/g). These shifts highlight the distinctive effects of MH and dormant cultivar Dh 8 on dormancy regulation compared to control.