Dissipation Pattern of Profenophos in Tomato.

Field experiment was carried out during kharif, 2012 to evaluate the dissipation pattern of most commonly used insecticide profenophos 50 EC @ 1000 g a.i. ha-1 with two sprays of insecticide, first given after fruit initiation and the second spray 10 days later and collecting the fruits at 0, 1, 3, 5, 7, 10, 15, 20 days after last spray, and analysed for residues using the validated QuEChERS method. The initial deposits of 1.16 mg kg-1 profenophos detected on tomato sprayed with profenophos @ 1000 g a.i. ha-1 were dissipated by 42.24% (0.67 mg kg-1) by 1st day, 56% (0.51 mg kg-1) by 3rd day, 73.25% (0.31 mg kg-1) by 5th day and below determination level (0.05 mg kg-1) by 7th day. A safe waiting period of 1 day is recommended considering Maximum Residues Limits (10 mg kg-1) of Codex Alimentarius Commission (CAC).

Bio-Efficacy of Insecticides Against Fruit Borer (Helicoverpa Armigera) in Tomato (Lycopersicon Esculentum).

Field experiment carried out during kharif, 2012 at Student’s Farm, College of Agriculture, Rajendranagar, Hyderabad to evaluate the efficacy of insecticides viz., emamectin benzoate 5 SG @11 g a.i. ha-1, emamectin benzoate 5 SG @ 22 g a.i. ha-1, profenophos 50 EC @ 500 g a.i. ha-1, profenophos 50 EC @1000 g a.i. ha-1, spinosad 45 SC @ 100 g a.i. ha-1, bifenthrin 10 EC @ 100 g a.i. ha-1 and Bacillus thuringiensis @ 25 g a.i. ha-1against tomato fruit borer (Helicoverpa armigera). Among all the insecticides, profenophos (1000 g a.i. ha-1) was found to be the most effective one with a maximum reduction in fruit borer population (65.20%), minimum per cent of fruit damage (28.80%) and maximum yield (26.43 kg/20 m2) followed by bifenthrin @ 100 g a.i.ha-1 with reduced larval population of 64.51% and damaged fruits 32.60%.

Dissipation Pattern of Bifenthrin in Tomato.

Field experiment carried out during kharif, 2012 to evaluate the dissipation pattern of most commonly used insecticide bifenthrin 10 EC @ 100 g a.i. ha-1 with two sprays of insecticide first given after fruit initiation and the second spray 10 days later and collecting the fruits at 0, 1, 3, 5, 7, 10, 15, 20 days after last spray, and analysed for residues using the validated QuEChERS method. The initial deposits of bifenthrin were 0.85 mg kg-1 which dissipated to 0.39, 0.15 mg kg-1 by 1st and 3rd day after last spray, respectively, and to BDL by 5th day. Bifenthrin initial deposits were dissipated to 82.35% by 3rd day after last spray, and pre-harvest interval of 3 days is suggested taking into consideration of MRLs of bifenthrin in tomato (0.3 mg kg-1) as per Codex Alimentarius Commission.