Control of Myzus Persicae Sulzer A Vector of Potato Viruses on Autumn Seed Crop with Phorate

Three doses of Phorate viz. 1.875 kg (18.750 kg Thimet 10G), 1.250 kg (12.500 kg Thimet 10G) 0.872 kg a.i./ha (8.750 kg Thimet 10 G/ha) were tested for the control of aphid vector of potato viruses at Ropar and Jullundur during 1971 and 1972. It was found that 1.250 kg (12.500 kg Thimet 10 G/ha) dose effectively prevented the aphid population from building up to the critical level of 20 aphids per 100 compound leaves. Phorate residues in potato tubers at harvest were below the tolerance limit of 0.5 ppm even in case of highest dose of 1.875 kg Phorate a.i./ha (18.750 kg Thimet 10 G/ha).