Management of collar rot ( Sclerotium rolfsii Sacc.) in sunflower (Helianthus annuus L.)

Sunflower (Helianthus annuus L.) is an important short duration crop which can be grown in all seasons and produces high quality edible and industrial oil, besides animal feed and fodders. Sclerotium rolfsii cause both pre and post-emergence mortality of young seedlings besides inciting collar rot in adult plants is considered to be potential biotic limiting factor for cultivation of sunflower. Keeping this fact in view, few fungicides and bio-agents were tested as seed treatment and soil application to manage the collar rot of sunflower under screen house and field conditions. Results indicated that use of fungicides and bio-agents as seed and soil treatments significantly reduced the incidence of collar rot. Under screen house conditions, maximum disease control (75.15 %) was obtained by Vitavax power (carboxin + thiram ) @ 2g/kg seed followed by captan 50 WP @ 3g/kg (70.35%).  Trichoderma harzianum @ 20g/kg soil application showed maximum control of the disease (40.62%) as compared to untreated control. Results of studies conducted under field conditions revealed that seed treatment with captan 50 WP @ 3g/kg seed was found most effective treatment in controlling the disease incidence (73.38 %). Among the different bio-agent evaluated, Pseudomonas fluorescensas  as soil application gave maximum disease control (55.11 %) of collar rot of sunflower and also maximum seed yield