Evaluation of Cassava ( Manihot esculenta Crantz) genotypes and their feeding values on the rearing performance of Eri-silk worm in southwestern Ethiopia

Field performance and leaf productivity of silkworm feed plants or genotypes are essential issues to be considered at start of sericulture business. In addition, the growth, development and economic characteristics of silkworms are significantly influenced by the quality of the feed. Hence, this experiment (both in the field and laboratory) was conducted at Jimma Agricultural Research Center (Melko station) during the main cropping seasons. The study was carried out to evaluate different cassava genotypes for adaptability, leaf productivity and silk yields of Eri-silkworms (Samia cynthia ricini Boisduval) fed on different cassava genotypes. Ten cassava genotypes were arranged in a randomized complement block design (RCBD) to evaluate agronomic performance, and the feasibility of cassava genotypes as Eri-silkworm feed was also evaluated in a complete randomized design (CRD) in three replications. A significant difference (P ≤ 0.05) was recorded in the agronomic performance of cassava genotypes in the field and the rearing performance of Eri silkworms. The cassava genotypes, including Kulle (5.7 ton/ha), M94/0117 (5.0 ton/ha) and 869 (4.6 ton/ha), were found to have significantly higher fresh leaf yield compared to other genotypes. The variation in fresh leaf yield observed is due to genetic difference and leaf moisture content among cassava genotypes. In addition, the findings also show that the rearing performance of Eri-silkworm was significantly higher in terms of effective rate of rearing and approximate digestibility when fed on leaves of 869, Umbure and Kulle. The study revealed that Umbure and 869 genotypes gave the largest cocoon weights (2.5 g), shell weights (0.3 g) and shell ratios (15.8%). Higher crude protein content was also recorded from leaves of genotype Kulle, M94/0117 and 869, with mean values of 28.6%, 27.1% and 26.9%, respectively. In general, the findings demonstrated that 869, Umbure and M94/0117 were found to be better-performing genotypes in terms of agronomic performance, crude protein, moisture, dry matter and ash content of leaves, and rearing performance of Eri-silkworms when fed leaves of these genotypes.