Rice gall dwarf

Rice gall dwarf is a systemic viral disease caused by the Rice gall dwarf virus (RGDV), which belongs to the Phytoreovirus genus. This pathogen invades the host plant tissues, causing significant physiological disruption that manifests primarily as abnormal morphological development.

The disease exclusively affects rice (Oryza sativa). When a field is infected, the virus interferes with the plant's nutrient transport, severely stunting its growth and rendering it unproductive, which poses a serious threat to rice production in endemic areas.

Typical symptoms include the formation of small galls or protrusions along the veins on the underside of leaves and leaf sheaths. Infected plants exhibit severe stunting, a bushy appearance due to excessive tillering, and leaves that appear darker green and stiffer than those of healthy plants, often failing to produce panicles.

The virus is transmitted by specific species of leafhoppers, most notably Nephotettix nigropictus and Recilia dorsalis. Once a leafhopper acquires the virus by feeding on an infected plant, it remains a vector for the rest of its lifespan. Warm temperatures and high humidity significantly accelerate the spread by promoting vector activity and migration.

Management of Rice gall dwarf focuses on integrated pest management (IPM). Key strategies include:

• Utilizing resistant rice cultivars.
• Monitoring and controlling leafhopper populations with systemic insecticides.
• Eliminating host weeds that act as reservoirs for the virus.
• Adjusting planting dates to avoid periods of high vector pressure.