Screening of Jatropha species against the major defoliators of castor (Ricinus communis L.)

摘要

Castor production in India is constrained by the vulnerability of the released varieties/hybrids to lepidopteran pests. In order to find out reliable sources of resistance for introgression into cultivars of the monotypic genus, Ricinus, members of the related genus, Jatropha, were screened against the leaf eating caterpillars. The Jatropha species showed varied levels of resistance to the different pests. Regardless of the pest, castor supported maximum survival, pupation and larval growth while Jatropha integerrima proved superior in terms of maximum mortality, very low weight gain with or without pupation. The other promising sources include J. integerrima Var. Rosea for castor semilooper and Bihar hairy caterpillar, J. podagrica for the hairy caterpillars and J. curcas for red hairy caterpillar.