Bioefficacy and dissipation studies of spiromesifen against mite, Polyphagotarsonemus latus banks on capsicum under field conditions

Abstract

Field experiments were conducted during 2013-14 and 2014-15 to evaluate the new insecticides for the management of mite, Polyphagotarsonemus latus banks and dissipation of effective insecticide on capsicum. Among the seven insecticides, mean of two seasons under poly house condition, population was less with spiromesifen (0.06 mites/ leaf) followed by diafenthiuron (2.21 mites/ leaf), triazophos (3.68 mites/ leaf) and thiamethoxam (5.30 mites/ leaf) which were significantly superior over untreated check (11.33). Spiromesifen residues were quantified through regular sampling till the residues are below determination level (BDL) of 0.05 mg kg -1 following the validated QuEChERS method. The qualitative and quantitative analysis of spiromesifen was performed on LC-MS/MS (PDA). Initial deposits of 1.61 mg kg -1 of spiromesifen detected at 2 hours after last spray, dissipated to BDL at 10 th day after spray. The half-life and safe waiting period for harvest was 2.09 and 10.00 days, respectively.

Dissipation kinetics and dietary risk assessment of spiromesifen on major summer vegetables using good agricultural practices

“…However, in contradiction to our investigation, Sushil et al (2018) observed longer persistence of spiromesifen residues on T A B L E 2 Recovery of spiromesifen from fortified okra, chilli, capsicum and brinjal fruits at various spiked levels (n = 5) hot pepper that declined below the detectable level of 0.05 mg/kg on day 20 in comparison with 10 days in our investigation. In capsicum, Pathipati et al (2017) observed initial spiromesifen deposits of 1.29 mg/kg at 125 g a.i./ha that declined below the limit of determination at day 7 after spraying. Vinothkumar et al (2018) reported 0.715 and 1.123 mg/kg initial deposits in brinjal in support of our finding of an LOQ of <0.05 mg/kg on day 7.…”

“…As evident from the residue data, the half-life of spiromesifen was worked out as 1.6, 1.8, 1.9 and 1.7 days in okra, chilli, capsicum and brinjal, respectively, in our results. Various researchers have indicated the half-life degradation of spiromesifen on different crops to be 1.68 days in okra (Raj et al, 2012), 2-2.5 days in chilli at various locations Sharma, Dubey, et al (2007a), 2.62 days in hot pepper (Varghese et al, 2011), 2.09 days in capsicum at an application rate of 125 g a.i./ha (Pathipati et al, 2017), 2-3 days in brinjal (Sharma et al, 2006), 5-6 days in apple and 5-8.5 days in tea (Sharma et al, 2005;Sharma et al, 2006).…”

“…On the basis of persistence of residue data generated from the present study generated from the supervised field trials conducted in accordance with the GAP and established MRLs fixed by the regulatory agencies, PHIs were calculated as 8.9, 5.2, 6.0 and 6.9 days, respectively for spiromesifen in okra, chilli, capsicum and brinjal. Pathipati et al (2017) recommended a waiting period of 10 days for spiromesifen at 125 g a.i./ha for the safe consumption of capsicum. Safe waiting periods of 1.40 and 2.18 days is recommended for brinjal @ 96 and 192 g a.i./ha doses of spiromesifen, respectively (Vinothkumar et al, 2018).…”

Dissipation kinetics, risk assessment, and waiting period of spiromesifen on chili fruits using gas chromatography–electron capture detector

“…The half-lives of spiromesifen at the single and double prescribed doses were 3.65 and 3.19 days, respectively, and the corresponding waiting periods were 0.74 and 4.49 days. Pathipati et al (2017) studied the dissipation pattern of spiromesifen on capsicum and found initial deposits of 1.29 mg kg À1 . Spiromesifen reached the below detectable level (BDL) in 7.0 days and the waiting period worked out for the safe harvest of capsicum was 7.0 days, which strongly supported the present findings.…”

“…Pesticide residues in food and their penetration into the food chain have sparked extensive public discussion. Few dissipation studies were performed to generate data on the effects of spiromesifen insecticides on chili fruits (Pathipati et al, 2017; Sharma, Rao, et al, 2007; Sushil et al, 2018; Varghese et al, 2011; VinothKumar, 2020; Viswanathan & Paul, 2020; Xavier & Chandran, 2016). Herein we report the dissipation kinetics and risk assessment of the effect of spiromesifen on chili fruits.…”