Incidence and role of rice stubbles on the survival of rice tungro virus disease in West Bengal.
The incidence of rice tungro virus (RTV) disease was monitored in standing crops and stubbles or ratoon crops in 2 districts of West Bengal, India, during aman season. This survey recorded RTV incidence in both local and high yielding varieties. Varieties like Khitish, Swarnadhan or Kalma had 20.5%, 23.3% and 34.1% infection, respectively. Results also emphasised that crop stubble might play a role in the inter-seasonal carry over of RTV by its leafhopper vector, Nephotettix virescens. The percentage of stubble infection ranged from 2.56 to 16.6% and infection on stubble exhibited different types of tungro symptoms. An indexing method using N. virescens confirmed rice tungro virus infection.