Enhancing biochemical composition of mulberry (Morus alba L.) through foliar nutrient application

Abstract

A study was conducted to evaluate the impact of foliar nutrition on the biochemical composition of mulberry (V-1 variety) at the College of Sericulture, Chintamani, during the Rabi and Summer seasons of 2023-24. The experiment followed a Randomized Complete Block Design (RCBD) with eleven treatments, each replicated three times. Among the tested treatments, the foliar application of humic acid + fulvic acid (0.25%) at 25 and 40 Days After Pruning (DAP) demonstrated the most significant enhancement in key biochemical parameters compared to other treatments. The results revealed that this treatment led to the highest leaf moisture content (80.02%), ensuring better leaf succulence, which is crucial for silkworm feeding. Additionally, it recorded the maximum total moisture retention capacity (92.20%), indicating improved water-holding ability in leaves. The total chlorophyll content (50.93 SPAD value) was also the highest, suggesting enhanced photosynthetic efficiency and leaf quality. Furthermore, the treatment significantly increased protein content (25.08%) and carbohydrate content (26.68%), both of which are vital for silkworm nutrition and cocoon production. These findings highlight that humic acid and fulvic acid, when applied at critical growth stages, improve the nutritional quality of mulberry leaves by enhancing moisture retention, chlorophyll synthesis, and protein-carbohydrate accumulation. This makes the treatment highly beneficial for sericulture farmers aiming to produce superior-quality mulberry leaves for silkworm rearing. Given these results, it is recommended that farmers adopt foliar sprays of humic + fulvic acid (0.25%) at 25 and 40 DAP to optimize the biochemical composition of mulberry leaves. Further research could explore the long-term effects of this treatment on leaf palatability, silkworm growth, and cocoon yield, ensuring sustainable sericulture practices. This study provides valuable insights into foliar nutrition strategies for improving mulberry leaf quality, supporting enhanced silk production.