Rice stripe virus disease
What it does
Rice stripe virus disease (RSVD) can cause high yield losses when severe epidemics occur.
The virus is transmitted in a persistent, circulative-propagative manner mainly by the small brown planthopper, Laodelphax striatellus Fallén. It is also transmitted by three other planthopper species, Unkanodes sapporona (Matsumura), U. albifascia (Matsumura), and Terthron albovittatum (Matsumura).
Why and where it occurs
Rice stripe virus disease occurs in the temperate regions of East Asia, specifically China, Japan, Korea, and Taiwan. It has also been reported in far-eastern Russia.
How to identify
Check for discoloration:
RSVD causes chlorotic to yellowish white stripes, mottling, and necrotic streaks on the leaves.
- Plants that are infected at the seedling stage have folded, twisted, wilted, and droopy leaves. They are stunted, have few tillers, may produce few panicles, and may die prematurely.
- Panicles produced by infected plants have whitish to brown and deformed and unfilled spikelets, and may not be fully exserted.
- Infected leaves at the maximum tillering stage or older have less severe chlorosis or mottling.
- Panicle exsertion and ripening of these plants may be delayed.
Why is it important
RSVD is one of the most serious diseases of rice in the temperate regions of East Asia. It can cause high yield losses when severe epidemics occur. It has affected several thousand hectares of rice-growing areas. Severe infection at the seedling to early tillering stage was reported to cause yield losses of 50−100%. In eastern China, RSVD has caused yield losses of 30−40% in 2003−04.
How to manage
- Grow resistant varieties.
Resistance to the virus is more effective in controlling RSVD than resistance to the vector. Contact your local agriculture office for an up-to-date list of available varieties.
- Adjust planting time so that the crop will be at the stem elongation stage or older during the peak of immigration of viruliferous insects from winter crops, specifically wheat and barley, as plants at the seedling to early tillering stages are highly susceptible to RSVD.
- Apply insecticides judiciously to reduce the population of viruliferous vectors. Indiscriminate application of insecticides has resulted in the resistance of populations to certain compounds
- Practice synchronous planting over wide areas.
- Remove ratoon or stubbles of the previous crop and weeds to reduce the virus and the population of the vector.