Uptake and Persistence of Cadusafos in Tomato

Varietal uptake of Cadusafos, an organophosphatic nematicide, in tomato Solanum lycprersicum (Mill.) was evaluated following its soil application as broadcast @ 2.0 kg ha⁻¹ and furrow @ 1.0 kg ha¹ at the time ef transplanting of one month old seedlings of varities Pusa Ruby and Pusa Sheetal in winter. Root and shoot samples were taken at different time intervals, processed and analysed using a FPD-GC. Cadusafos persisted in both root and shoot up to 105–120 days. Root absorption was rapid but further translocation to shoot was slow. The residues accumulated in roots up to 15 days measuring as high as 2.81 μg g⁻¹. Shoot contained highest residues (0.70 μg g⁻¹) by day 7 of treatment. Absorption and translocation of residues varied among the two tomato varieties. Uptake of cadusafos was more in Pusa Ruby than Pusa Sheetal. The residue levels in fruits were very low (0.002–0.009 μg g⁻¹ in Pusa Ruby and 0.004–0.007 μg g⁻¹ in Pusa Sheetal) by 90 days and non-detectable by 120–130 days, which were below its MRL 0.024 ug gu fixed for potatoes. Hence, the application of cadusafos in tomato as broadcast @ 2.0 kg ha⁻¹ and furrow w 1.0 kg ha⁻¹ can be considered safe from the angle of toxic residues.