SUNFLOWER :: MAJOR DISEASE :: NECROSIS

Necrosis -Tobacco streak virus (TSV)

Symptoms

Characterised by the sudden necrosis of part of lamina followed by twisting of leaves and systemic mosaic. Necrosis of lamina of the lamina, petiole, stem floral calyx and corolla.               

• Black streak on stem	Necrosis of stems and petioles, terminal growth	curls down and plants often lodge

  Advanced symptoms lead to plant death.

Pathogen

            Caused by Tobacco streak virus an Ilarvirus 25-28 nm, tripartite genome encapzidated separately

Disease cycle

            Virus spreads through transmission by thrips Frankliniella schultzii. Weed hosts serve as natural virus reservoirs. Long and continuous dry spell increases the disease incidence

Management

• Removal of weed hosts
• Management of veetor population
• Changing planting dates