Persistence of Fluopyram and Tebuconazole as Combination Product in Chilli (Capsicum annuum L.)

Persistence of fluopyram and tebuconazole on chilli fruits following foliar application of their combination product in a field experiment is reported during 2014–15 at a farmer's field. The average initial deposits of fluopyram, 1 h after the third application were 0.75 and 0.93 μg g⁻¹ in the fruits at the standard and the double doses, respectively. On the 20^th day, the residue reached below determination level at the standard dose whereas it was 0.08 μg g⁻¹ at the double dose. In case of tebuconazole, the average initial deposits observed were 0.69 and 1.11 μg g⁻¹ which reached below determination limit (0.05 μg g⁻¹) on 15^th day at the standard dose and was 0.06 μg g⁻¹ at the double dose on the 20^th day. The dissipation of fluopyram and tebuconazole in chilli fruits followed first-order kinetics with half-life between 5.6–5.7 and 3.5–4.5 d, respectively. Residues of both the fungicides in red chillies collected at harvest were below determination level of 0.05 μg g⁻¹. Soil samples drawn on the 20^th day after the last spray revealed residues of both the fungicides below determination level at the standard dose and at the double dose, fluopyram and tebuconazole were detected at 0.11 and 0.26 μg g⁻¹, respectively.