Effect of Mulberry Irrigated with Treated Sewage Water on Silkworms and Cocoon Production

Aim: The experiment was aimed at evaluating the effect of mulberry irrigated with treated sewage water on silkworms and cocoon production. 
Study Design: The experiment was laid out in a Randomized Complete Block Design (RCBD) with six treatments and four replications. 
Place and Duration of Study:  The study was conducted during Rabi 2019 in pre-established irrigated V-1 mulberry garden at Department of Sericulture, University of Agricultural Sciences, Gandhi Krishi Vigyana Kendra, Bengaluru, Karnataka, India. 
Methodology: A field experiment was conducted in a V1 mulberry garden established under paired row system to study the influence of raw and treated sewage water irrigation on growth of mulberry and subsequent effect on silkworm (PM × CSR2) growth and cocoon parameters. The raw and treated sewage water was collected from GKVK sewage treatment plant and irrigated to mulberry garden. Silkworms fed with mulberry leaves raised on recommended dose of NPK kg/ha/year + FYM along with raw and treated sewage water irrigation showed positive influence on late age silkworms. 
Results: Observations recorded on silkworm growth and cocoon parameters revealed that significant higher fifth instar larval weight (32.02 g/10 larvae), ERR (99.0 %), single cocoon weight (1.706 g), pupal weight (1.385 g), shell weight (0.321 g), shell ratio (18.65%) and shorter fifth instar larval duration (181.91 hrs). Similarly, reeling parameters of cocoons showed significantly longer filament length (853.00 m) and higher filament weight (0.28 g) in silkworms fed with mulberry leaves from the plots irrigated with raw sewage water.