Screening of Suitable Castor Cultivars for Ericulture in Tamil Nadu, India

Although castor cultivation is predominant in Gujarat, Andhra Pradesh, Tamil Nadu, and few other states in India, rearing of eri silkworm, which feeds on castor is not catching up in these non-traditional states. One of the probable reasons is the non-availability of studies indicating region-specific suitable castor cultivars for different eri silkworm races. Studies on castor cultivar preference for one such better-performing race, C2 yielding better shell weight (12-15 Kg/100 DFL) in the Tamil Nadu region is lacking. Eleven castor cultivars, including local accessions, varieties, and hybrids, have been raised in Randomised Block Design (RBD) with three replicates. The worms were reared using all the grown cultivars with five replications for each cultivar (treatment) with 20 worms/replication. All the economic parameters of eri silkworm were computed and compared. Local accessions such as Krishnagiri local and Tindivanam local, Perennial castor - YTP – 1, and Hybrids such as YRCH – 1 and DCH – 519 recorded significantly better larval, cocoon, and reproductive parameters. Least larval duration and highest matured larval weight were recorded in Krishnagiri local accession. Least values of all the economic parameters were noticed in Dharmapuri local. The reason might be due to the poor leaf quality impacted due to severe whitefly (Trialeyrodes ricini) and red spider mite (Tetranychus urticae) attack.