Extra-early maturing germplasm for utilization in castor improvement

Diverse sources of extra-earliness are required for breeding high yielding extra-early castor (Ricinus communis   L.) cultivars. Twenty-three extra-early accessions and four checks were evaluated from 2003–2004 to 2007–2008. Variance components for 14 traits and correlation coefficients were estimated. Significant genotypic differences were observed for these traits. Number of main stem nodes, days to 50% flowering and days to maturity exhibited high σg2 and non-significant σg×e2 interactions. They showed significant high positive correlations with each other and very low associations with yield and its components. Yield exhibited moderate associations with its components except 100-seed weight. Cluster analysis grouped the entries into four groups. All 23 accessions exhibited stable performance for extra-early maturity. Accessions were identified for high oil content, high yield and high per day productivity. The promising accessions identified and the information generated would be useful for breeding extra-early cultivars as well to study inheritance of extra-earliness.