What to do?
- Select a planthopper resistant cultivar suitable in the area.
- Plant healthy seedlings in 15 x 20 or 20 X 20 cm spacing or leave 0.3 m alley ways across the field at every 3 m of planting. (Spacing to be adjusted based on rice variety)
- Do periodic surveillance for the pest population, once in a week or 10 days. Walk diagonally across the field and examine one hill at every 5 m for presence of planthoppers. Count number of adults and nymphs and also the number of mirid bugs and spiders.
- Take appropriate control measures when warranted.
- Drain the field mid season.
When to do?
- Prior to the season, decide on the most suitable planthopper resistant/tolerant variety or hybrid (Resistant Brown Planthopper Varieties, White Backed Planthopper Varietie, BPH & WBPH Varieties)
- At the time of transplanting adopt line planting for easy intercrop operations. If not feasible, leave alley ways of 0.3 m width after every 5-10 meters of planting. This will help in application of fertilizers, and directing insecticides at the base of the plant.
- Beginning with 30 days after transplanting, regularly monitor the planthopper population on selected random hills across the field walking across diagonally. Repeat sampling every week or 10th day. Next sampling be done across another diagonal path. Record number of planthopper nymphs and adults and also that of predatory mirid bugs and spiders.
- When the population reaches ET level take suitable chemical control. (Effective chemical control for the planthoppers)
- During active tillering to PI stage (after 45 days of transplanting) drain the field to reduce humidity.
How to do?
- Line planting can be achieved with the help of a rope held stretched across the field. After every 15 rows of planting one row may be skipped to form the alley way.
- For sampling the insect population, it is best to take a yellow pan with water, hold it at the base of the hill and gently tap the base of the plant to drop insects onto the water in the pan. Then count the insects and record.
- Effective chemical may be used at recommended concentration and dosage Direct the spray fluid at the base of the plants where the planthoppers generally feed. Alley ways help in this operation. Do not repeat spray application within 10 days, even if planthopper populations are seen in low numbers. Such repeated sprays may lead to resurgence of the pest.
What not to do?
- Do not go for close planting of 10 x 10 or 10 x 15 cm spacing.
- Do not apply excess dose of nitrogenous fertilizers (not more than 100 or 120 kg N during kharif or rabi, respectively).
- Do not go for an early spray of insecticide (before 30 days of transplanting) against pests like whorl maggot, leaf folder or gall midge. If required against stem borer or gall midge, apply granular insecticide.
- Do not spray insecticide if the planthopper population is below ET level.
- Do not spray same insecticide within 10 days, even if there is residual population of the pest.
Why not to do?
- Closer planting leads to early closure of crop canopy and create suitable micro-climate with high humidity and less access to the natural enemies. This will help in buildup of planthopper population.
- Excess dose of nitrogen leads to luxurious growth of the crop, early closure of crop canopy and more suited for planthopper feeding and oviposition.
- Early stage leaf damaging pest like whorl maggot does not cause much economic loss. Even low levels of leaf folder damage does not warrant sprays. On the other hand, early sprays can eliminate natural enemies of planthoppers and help buildup of pest population. On the other hand, granular application is safer and effective against gall midge and stem borers.
- Precocious sprays of effective or non-effective insecticides can only buildup the pest by eliminating natural enemies.
- Repeating the same insecticide may help development of resistance in the pest population. Even otherwise, it will eliminate natural enemies and help in build up of the pest.
Brown Planthopper -Recap Sheet
Rice Varieties resistant to BPH-Click Here
Directorate of Rice Research, Hyderabad