Analysis of cyantraniliprole residues in beetroot and beet top using LC-MS/MS, dietary exposure assessment, and evaluation of decontamination techniques.

A modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method was standardized for the analysis of cyantraniliprole residues in beetroot and beet top (Beta vulgaris ssp. vulgaris L.) using liquid chromatography-mass spectrometry/mass spectrometry. Samples were extracted with acetonitrile and cleaned up by dispersive solid phase extraction. Acceptable recovery of 84.74%-104.24% for beetroot and 80.19%-118.55% for beet top matrix was achieved at fortification levels ranging from 0.02 to 0.025 µg g-1 , with relative standard deviation <20% that signified the application of the method for detecting cyantraniliprole residues. A field experiment was conducted to determine the half-life and preharvest interval for cyantraniliprole residues in beetroot and beet top. The half-life obtained was 1.86-2.7 days for beetroot and 3.65-5.33 days for beet top. The preharvest interval calculated was 9.12-12.90 and 22.12-37.98 days for beetroot and top, respectively. The dietary exposure assessment at studied doses found cyantraniliprole residues below acceptable daily contact limits. Among different decontamination techniques evaluated, peeling + tap water washing resulted in a higher reduction of residues while cooking and juicing resulted in moderate removal of residues.

Effect of decontamination and processing on insecticide residues in grape (Muscat Hamburg).

Field and laboratory experiments were conducted to study the effect of simple decontamination methods and processing on imidacloprid, dimethoate, and emamectin benzoate residues in grapes and their processed products by liquid chromatography-mass spectrometry. Among the decontamination methods evaluated, washing with NaCl (2%) solution was effective for reducing imidacloprid (77.55%), dimethoate (83.27%), and emamectin benzoate (77.28%) residues in mature grapes. No metabolites (omethoate and 6-chloronicotinic acid) were detected in both decontamination and processing studies. The grapes were processed into various products, including fresh juice, squash, and raisin, following the standard effective steps for each product. Washing with NaCl (2%) solution for decontamination was included as an additional step in the standard protocol and resulted in substantial removal of surface residues of the selected insecticides. The processing factor calculated was less than one for all the products.

Impact of drought stress on simultaneously occurring pathogen infection in field-grown chickpea.

Drought stress and pathogen infection simultaneously occur in the field. In this study, the interaction of these two stresses with chickpea, their individual and combined effect and the net impact on plant growth and yield traits were systematically assessed under field and confined pot experiments. The field experiments were conducted for four consecutive years from 2014-15 to 2017-18 at different locations of India. Different irrigation regimes were maintained to impose mild to severe drought stress, and natural incidence of the pathogen was considered as pathogen stress. We observed an increased incidence of fungal diseases namely, dry root rot (DRR) caused by Rhizoctonia bataticola, black root rot (BRR) caused by Fusarium solani under severe drought stress compared to well-irrigated field condition. Similar to field experiments, pot experiments also showed severe disease symptoms of DRR and BRR in the presence of drought compared to pathogen only stress. Overall, the results from this study not only showed the impact of combined drought and DRR stress but also provided systematic data, first of its kind, for the use of researchers.