Effect of soaking seed in S3307 on production performance and physiological indices of continuous cropping alfalfa

Continuous cropping of alfalfa (Medicago sativa) is harmful to the plant. To overcome the obstacle of continuous cropping, the regulation effect of soaking seed with different concentrations of uniconazole (S3307) on the continuous cropping stress of Alfalfa was studied. After soaking seeds with different gradient solutions of S3307 0 (CK), 20, 30, 40, 50, and 60 mg·L⁻¹ for 8 h, the biological characteristics, and physiological and biochemical indices after 60 days of growth and development were studied by continuous soil pot culture. The results showed that when the concentration of S3307 was 40 mg·L⁻¹, it had the highest regulation effect on continuous cropping alfalfa and significantly increased the root length, above-ground and below-ground biomass, and leaf proline content. It also decreased the content of MDA in leaves. S3307 seed soaking can effectively alleviate the adverse effects of continuous cropping stress, increase yield, improve alfalfa stress resistance, achieve the expected effect of alleviating continuous cropping obstacles, and provide a scientific basis for regulating continuous cropping.