Rice Tungro

Kannada Name: Tungro Roga

            Rice tungro is one of the most destructive viral disease particularly in north eastern and eastern coastal regions of peninsular India. The word tungro means degenerated growth.

Period of occurrence: All stages of crop growth, starting from nursery

Vectors of virus particles :

            The principal vector is Nephotettix virescens, other green leaf hoppers, N. nigropictus, N. parvus, N. malayanus and Recilia dorsalis also transmit the virus, but at a lower rate.

Alternate hosts: Grassy weeds, Eleusine indica, Echinochloa colonum, Echinochloa crusgalli, Ischaemum rogosum, Dactyloctenium aegyptium.     

 Mode of transmission: Depends on the

• Availability of virus infected plants
• Insect vector population
• Susceptibility of the variety

Sources of inoculum: Stubbles of the infected plants from previous season and ratoon, grassy weeds.

Symptoms:

• Severe stunting and reduction  in the number of tillers
• Affected leaves are often light yellow to orange yellow. Young leaves are often mottled or have pale green to white stripes of different lengths running parallel to the veins.
• Normally patches of the plants are affected across the field.
• Delayed flowering and panicle insertion is often incomplete
• Infected panicles are small and sterile or only partially filled with discolored grains.

Preventive measures:

• Use of resistant varieties: Vikramarya, Nidhi, Radha, Annapurna, Triveni
• Removal of infected plants at early crop growth stages
• Destruction of stubbles after harvest in infected fields.
• Vector management
• Crop rotation with pulses/oilseeds in endemic areas.

Vector: leaf hopper

Individual Seedling

Tungro affected field view