Vol. 10, Special Issue 1, Part I (2026)

Mulberry (Morus spp.) leaves serve as the sole nutritional source for the mulberry silkworm, Bombyx mori L., and their biochemical composition plays a crucial role in silkworm growth, cocoon yield and silk quality. The present study evaluated variations in major primary and secondary biochemical constituents of mulberry leaves across different varieties and leaf maturity stages. Eight mulberry varieties viz., Mysore Local, Sahana, S36, DD, AR12, V1, G2 and G4 were cultivated under uniform agronomic conditions at the College of Agriculture, Mandya, Karnataka. Leaf samples were collected 45 days after pruning and analysed for total chlorophyll, crude protein, total carbohydrates, crude fibre, total phenols, proline and tannins using standard biochemical methods. The results revealed significant varietal and leaf maturity-dependent variations in all biochemical parameters. Chlorophyll content increased from 1.79-1.98 mg g⁻¹ in young leaves to 2.27-2.76 mg g⁻¹ in matured leaves, with Sahana, V1 and G4 recording the highest values. Crude protein content declined with maturity, ranging from 21.94-24.36% in young leaves to 18.22-20.16% in matured leaves, with V1 and G4 consistently exhibiting superior protein levels. Total carbohydrate content increased from 16.08-20.58% in young leaves to 18.14-22.02% in matured leaves, with V1 registering the maximum concentration. Crude fibre content increased with maturity (7.54-9.06% to 8.30-9.84%), though V1 and G4 maintained relatively lower fibre levels in young leaves. Secondary metabolites such as total phenols (3.02-4.32 mg g⁻¹), proline (8.92-12.18 µmol g⁻¹) and tannins (1.02-1.39 mg g⁻¹) were higher in young leaves and declined with maturity. Overall, the study underscores the importance of varietal selection and leaf maturity in determining mulberry leaf biochemical quality, with V1 and G4 emerging as superior varieties for enhancing silkworm performance and cocoon productivity.