Bridging the Gap: Agronomical Constraints and Extension Needs in Mulberry Farming - A Case Study

Mulberry plants require optimal soil, climate, nutrients, water, and their management practices to produce high-quality leaves suitable for silkworm rearing. Healthy silkworm growth and cocoon productivity depend on leaf moisture, protein content, sugars, vitamins and mineral composition. Mulberry thrives in deep, well-drained loamy soils with a slightly acidic pH and high organic matter, supporting strong root development and nutrient uptake. Moderate temperatures of 24–28°C, 70–80% relative humidity and adequate sunlight with protection from extreme heat promote tender, succulent leaves preferred by silkworms (Dandin et al., 2003). Consistent soil moisture without waterlogging enhances leaf moisture and protein levels. Balanced nutrient management with nitrogen, phosphorus, potassium, secondary nutrients (calcium, magnesium, sulphur) and micronutrients (zinc, iron, manganese, boron, copper) maintains high chlorophyll content and biochemical composition. Proper pruning, timely harvesting of chawki leaves, efficient irrigation at critical stages, organic amendments and integrated pest and disease management ensure continuous production of nutritious foliage. Selecting high-yielding, high-nutrition mulberry varieties improves leaf quality and productivity, benefiting larval growth, cocoon weight, silk filament length and sericultural profitability. Mulberry plants will become weak and produce low-quality, poor nutritious leaves when exposed to a combination of soil, climate, nutrient, water, pest, and management stresses that disrupt their physiological processes. Factors such as poor soil fertility, imbalanced nutrient supply and low organic matter can reduce root development and limit the uptake of essential nutrients crucial for leaf protein, chlorophyll and moisture content. Water stress from irregular rainfall, inadequate irrigation or prolonged drought can decrease photosynthesis and lead to coarser leaves, while waterlogging can damage roots and reduce nutrient availability. Extreme temperatures, low humidity and high solar radiation can further impact leaf tenderness and biochemical quality required for silkworm digestion. Soil acidity, salinity and compaction can restrict root growth and nutrient absorption, while continuous monocropping without soil amendments can deplete nutrients and decrease microbial activity. Pest and disease attacks, such as nematode infestation, leaf spot, rust, powdery mildew, rot, borers, whitefly, thrips, jassids, leaf roller, mites and tukra etc., can cause leaf damage, chlorophyll loss and reduced photosynthetic area, directly affecting leaf nutrient composition. Inadequate pruning, poor canopy management and improper harvesting intervals can result in aged, fibrous leaves with reduced protein and moisture content. Additionally, using unsuitable or low-yield varieties not adapted to local agro-climatic conditions can contribute to weak growth and inferior leaf quality. These biotic and abiotic stresses collectively weaken the plant'sphysiological vigor, disrupt nutrient metabolism and ultimately lead to poor-quality mulberry leaves that do not meet the nutritional needs of silkworms.

Mulberry cultivation and silkworm rearing are highly skilful and proper management practices essential for achieving crop success. Many farmers who are being engaged in sericulture for the past three decades have acquired practical knowledge through experience and learning from fellow farmers. Skilled farmers are able to assess mulberry crop stages and implement timely pruning, nutrient application, irrigation, weed management and pest and disease control to ensure the production of high-quality leaves. They also rely on visual observations of leaf quality to determine suitability for silkworm feeding, thereby safeguarding crop productivity. However, the majority of farmers fail to recognize several non-productive practices that reduce silkworm productivity, either immediately or over the long term.

This case study documents these critical agronomic constraints observed during field engagements with sericulture farmers in Karnataka and provides scientific analysis to bridge the knowledge-practice gap through targeted extension.