Curry leaf [Murraya koenigii (L.) Sprengel] is a leaf spice of the citrus family Rutaceae. Curry leaves forming an integral part of spicing up dishes are not a part of mere garnishing. They are rich in medicinal, nutraceutical properties and have even cosmetic uses. In India, of late it is cultivated on commercial scale (Tamil Nadu, Karnataka, Andhra Pradesh and Telangana) and has gained importance as a major spice crop with high export potential [1] . A total of 12 insect pests belonging to 10 families of 5 orders were recorded infesting curry leaf plants [2] . As per Insecticides act 1968, there is no pesticide recommendation for spray on curry leaf as on today and hence there are no MRLs suggested by Codex Alimentarius Commission. However, farmers are using pesticides indiscriminately that are designed to control the pest even if there are no recommendations for the crop and whether the pest is present or not. Hence, residues were detected at the farm gate level for export location and led to the rejection of the consignment [3] . According to the report of the Indian delegation at the 45th session of the Codex Committee on Pesticide Residues (CCPR) held at Beijing, China (6-11 May, 2013) in agenda no. 11, India is considered for fixation of new and revised MRLs of profenophos, chlorpyriphos, cypermethrin, methyl parathion, triazophos, ethion and quinalphos in curry leaves based on Good Agricultural Practice (GAP) trials and monitoring data and should submit in the prescribed format to Joint FAO/WHO Meeting on Pesticide Residues (JMPR), as a follow-up, for evaluation in 2014 for fixation of MRL on curry leaves. By keeping in view all these most important issues of concern, the present comprehensive study, on dissipation of newer insecticides viz., triazophos and chlorpyriphos, was carried out in curry leaf.

A field experiment was conducted during kharif, 2014 and 2015 at Department of Agroforestry, College of Agriculture, Professor Jayashankar Telangana State Agricultural University (PJTSAU), Rajendranagar, Hyderabad with seven treatments and three replications in Randomized Block Design (RBD) on curryleaf Variety Suwasini. The experimental site is situated in Southern Telangana Zone with semi-arid climate and between 17˚19' North latitude, 78˚23' East longitude and 542.3 m above mean sea level utilizing the insecticidal treatments viz., triazophos 40 EC at 500 g a.i. ha⁻¹ and chlorpyriphos 20 EC at 300 g a.i. ha⁻¹ sprayed twice, first at vegetative stage and second at 10 days after first spray with hand compression knapsack sprayer and the amount of spray fluid used was 500 l∙ha⁻¹. The laboratory studies (2015-16) were carried out in the All India Network Project on Pesticide Residues, Extension Education Institute premises, Rajendra-nagar, Hyderabad. The weather parameters during the crop period are given in Table 1.

The initial deposits of triazophos 40 EC @ 500 g a.i. ha⁻¹ and chlorpyriphos 20 EC @ 300 g a.i. ha⁻¹ were 18.19 and 14.73 mg∙kg⁻¹, respectively which dissipated to below determination levels (<0.05 mg∙kg⁻¹) at 20 and 15 days, respectively. The half-life values were 2.08 and 1.43 days, respectively. As there were no MRLs fixed, the day at which residues reached to BDL was suggested as safe harvest i.e., 20 and 15 days, respectively. Soil samples collected at harvest (45th day) were free from the residues of both pesticides (Table 3, Table 4, Figure 1 and Figure 2). The initial deposits of 1.10 mg∙kg⁻¹ of triazophos detected in fruit samples of tomato, dissipated to BDL by the 7th day [4] . [5] reported initial deposits of 2.13 mg∙kg⁻¹ reached BDL on the 10th day with half-life of 1.78 days in capsicum. The variation of results pertaining to the initial deposits (18.19

mg∙kg⁻¹) may be due to variation in dosages of application, change in matrix and climatic conditions. Results were in agreement with the work done by [6] , who reported the initial deposit of 15.40 mg∙kg⁻¹ of chlorpyriphos in curry leaf which reached BDL by the 15th day with half-life of 1.5 days and safe waiting period of 14.08 days. Similar results were obtained by [7] on curry leaf with different pesticides. The insecticide dose used with a spray interval of 10 days to protect leaves can lead to residues being detected at the farm gate level or export location and rejection of the consignment. Curry leaves from India are contaminated with insecticides, with 40% containing residues exceeding maximum residue limits of chlorpyriphos, triazophos [8] . Inappropriate insecticide use among curry leaf farmers makes it necessary to evaluate plant products, horticultural mineral oils and green-labeled insecticides against major pests of curry leaf to reduce hazards of insecticides residues. Information on use of insecticides that are safer to natural enemies, utilization of plant products and bio-agents for pest management and knowledge on pesticides dosage, application intervals and insecticide residues are needed so that internal use and export of the commodity are safe. The crops affected by some pests and diseases, trigger off major losses of quality crops and initiate the use of more pesticides. Therefore, an effective way of educating the farmers via training and electronic media is advised particularly in view of the export potential of the crop to reduce the risk of rejection at export level.

Gogikar, P., Vemuri, S., Reddy, C.N. and Senivarapu, S. (2017) Dissipation Pattern of Triazophos and Chlorpyriphos in Curry Leaf. Open Access Library Journal, 4: e3134. http://dx.doi.org/10.4236/oalib.1103134