Impact of regulated deficit irrigation on leaf biochemical quality and silkworm performance: A comprehensive review

Abstract

Water scarcity has become one of the major challenges in agricultural production systems, particularly in perennial crops such as mulberry (Morus spp.), which requires continuous irrigation for sustained leaf production. Regulated Deficit Irrigation (RDI) is an irrigation strategy in which water is supplied below the full crop water requirement during certain growth stages to improve water use efficiency without causing significant yield loss. In mulberry cultivation, irrigation significantly influences leaf yield, biochemical composition and nutritional quality, which directly affect the growth and productivity of the silkworm (Bombyx mori L.). Mulberry leaves contain essential nutrients such as proteins, carbohydrates, amino acids, chlorophyll, vitamins and minerals that determine silkworm growth, cocoon production and silk quality. Several studies have reported that moderate deficit irrigation improves water use efficiency while maintaining or enhancing biochemical parameters such as soluble proteins, sugars and chlorophyll content in mulberry leaves. Improved leaf biochemical quality enhances larval growth, feed conversion efficiency, cocoon weight, cocoon shell ratio and filament length in silkworms. However, severe water deficit may reduce leaf moisture and nutrient accumulation, negatively affecting silkworm performance. Therefore, regulated deficit irrigation represents an effective strategy for sustainable mulberry cultivation under water-limited conditions. This review summarizes the impact of regulated deficit irrigation on mulberry growth, leaf biochemical quality and the subsequent performance of silkworms.