Cassava Leaves Defoliation for Eri Silk Worm Rearing and its Impact on Cassava Tuber Yield

Abstract

Two experiments, one at experimental farm, Department of Horticulture and another experiment atdepartmental lab in the Department of Sericulture, Assam Agricultural University (AAU), Jorhat, Assamwere carried out during 2013-2015. The first experiment was conducted with four varieties of cassavaand its’ four leaf defoliation levels. In the second experiment, effect of leaf feeding byerisilk wormwas studied on the four varieties of cassava and the study was conducted for two seasons. In both theexperiments significant treatment effects were observed. The tuber yield reduced at defoliatedtreatments in all the varieties. The result in leaf defoliation level was opposite to tuber yield in the firstexperiment. The second experiment results revealed that cassava varieties had significant effect onlarval growth, cocoon yield and cocoon characters oferisilkworm. The larval duration, larval weight,cocoon yield, cocoon weight and pupal weight were found to be better in spring season; while,autumn rearing was registered better for shell ratio percentage of the cocoon. The economic analysisrevealed that cassava production was more profitable, when sericulture component was included.There was additional net income of Rs 41895/- from sericulture component.