Persistence and Ecological Risk Associated with a Combination Ready Mix Sumiprempt Formulation in Soil under the Cover of Okra Crop

Author: Pooja, Sushil Ahlawat, Ashu and Rahul Kumar

Download PDF

Abstract

Sumiprempt, containing pyriproxyfen and fenpropathrin as active ingredients, has high potential for managing okra pests. Taking into account their potential hazards to non-target organisms and the associated environment, a field experiment was conducted to assess persistence and associated risk to various non-target organisms. Achieving efficient chromatographic separation of two pesticides can be challenging due to differences in their chemical properties, such as volatility, polarity, and structural characteristics. It is very time consuming, laborious and non-ecofriendly method due to the use of large amount of solvents in the extraction of the two pesticides simultaneously. Thus, by using GC-MS/MS, this study attempts to develop a rapid and less expensive QuEChERS method to extract and clean pyriproxyfen and fenpropathrin residues in soil simultaneously. Several factors were investigated in order to validate the effectiveness of the method, including the impact of spiking concentration, matrix effect (ME), repeatability between and within assays, reproducibility of results, and precision. For both analytes, the limit of determination (LOD) and limit of quantitation (LOQ) are 0.005 mg/kg and 0.01 mg/kg, respectively. The percentage recovery for both insecticides ranged between 87.8 and 97.7% with a relative standard deviation (RSD) below 7.09%. The foliar application of Sumiprempt formulation was applied at recommended (37.5 + 112.5 g a.i. /ha) and double recommended dose (70 + 225 g a.i. /ha) in the soil led to very low initial deposits of pyriproxyfen (0.029, 0.047 mg/kg) and fenpropathrin (0.054, 0.097 mg/kg) at respective doses. Both insecticides were not found to persist after 1st day of application. The risk quotient values for pyriproxyfen were in the range of 0.01-0.1 and for fenpropathrin greater than 0.1, implying that pyriproxyfen offers low risk whereas fenpropathrin offers moderate risk to soil invertebrates at both doses. This clearly indicates that longer persistence of these insecticides in soil can be toxic to organisms other than those that are targeted.

Keywords

Combination formulation, QuEChERS, risk assessment, pyriproxyfen and fenpropathrin

Conclusion

It can be concluded from the above results that the methodology used for the extraction and cleanup of soil samples was simple, sensitive, selective, and repeatable and could be extended for monitoring various formulations based on the above premix formulation. The application of sumipremt formulation results in a very low amount of pyriproxyfen and fenpropathrin residues in soil under the cover of the okra crop. Due to the high temperature and humidity conditions in the field, residues persisted only for 1 day after the application (DAA). These lower amounts of pyriproxyfen and fenpropathrin, however, posed low and moderate risks to earthworms. Consequently, if farmers do not comply with recommended doses, residues of pyriproxyfen and fenpropathrin will pose an unacceptable risk to earthworms in the soil under the okra crop.

References

-

How to cite this article

Pooja, Sushil Ahlawat, Ashu and Rahul Kumar (2023). Persistence and Ecological Risk Associated with a Combination Ready Mix Sumiprempt Formulation in Soil under the Cover of Okra Crop. Biological Forum – An International Journal, 15(2): 1281-1288.