Path Coefficient Analysis of Some Prominent Agronomic Traits in Castor (Ricinus communis L.) Germplasm

Background and Objective: Castor (Ricinus communis L.) is a diploid plant with chromosome number of 2n=20 which belongs to family of Euphorbiaceous and genus Ricinus. Correlation alone is not efficient for variability studies. So, it should be in conjugation with Path co- efficient analysis to know the direct and indirect effects. This study was conducted to assess the role of evaluating path coefficient analysis in castor.

Materials and Methods: A Field experiment was carried out to determine direct and indirect effects of yield and its components in castor accessions at Melkassa, central rift valley of Ethiopia under irrigation in 2014. The experiment was conducted using a randomized complete block design with 3 replications and a total of 48 castor accessions were evaluated.

Results: Number of capsules per plant, number of primary branches per plant, length of inter node and hundred seed weight had exerted positive direct effect for both at phenotypic and genotypic path analysis.Phenotypic and genotypic path analysis showed that the number of capsules per plant, number of secondary branches per plant, length of inter node, days to 50% second flowering and seed yield exhibited positive direct effect on oil content.

Conclusion: Thus, traits like number of capsules per plant, number of secondary branches per plant, length of inter nod and days to 50% second flowering should be given emphasis in improving seed yield.