Screening of Castor Germplasm and Efficacy Studies of Bioagents and Fungicides Against Botryotinia ricini (Godfrey) Whetzel

Castor is an important non-edible oilseed crop having exceptional oil characteristics for the chemical industry. The crop hosts several diseases, among them gray mold is the most destructive one hindering its productivity. This article presents a study assessing the resistance of different germplasm lines screened against Botrytis ricini under artificial conditions. It also examines the effect of various fungicides on B. ricini isolates, which were obtained from infected Ricinus communis (castor oil plant) using standard tissue isolation techniques. The fungus was isolated from infected Castor raceme by standard tissue isolation technique and its pathogenicity was established by proving Koch’s postulates. Out of 47 germplasm lines screened, TSIL-19 showed resistance response to gray mold under both detached spike and capsule method. Under in vitro assessment, Trichoderma viride (86.11 %) and Pseudomonas fluorescens (71.48 %) bio agents exhibited maximum mycelial growth inhibition of the pathogen. Among the seven combination fungicides evaluated, Fenamidone 10% + Mancozeb 50% WG recorded highest mycelial growth inhibition (100%) of B. ricini.