Tamilnadu Agricultural University, Coimbatore-641 003.
*Regional Agricultural Research Station, Palem -509215.
Pre-inoculation sprays with seed oils extracted from cotton, neem, Pongam, mustard and Kapak reduced tungro transmission and survival of the vector and increased the incubation period of tungro virus complex in rice plants. Reduction in the number of infected plants was maximum in cotton seed oil (88.8% over control) whereas the period of incubation was maximum in neem oil treated plants (78.8% over control). In cotton seed oil, neem oil and Pongam oil sprayed plants, all the insects died on the sixth day after application. Neem oil and Pongam oil were found to reduce tungro transmission up to five days after spraying. However, cotton seed oil was effective only up to three days.
