Three applications of beta cyfluthrin + imidacloprid (Solomon 300 OD) @ 30 g a.i ha-1 were made to Dolichos bean viz., the first application was made at the 50% blooming stage, and the second and third applications were made at intervals of 10 days. For the purpose of analysing the dissipation pattern, green pod samples were regularly taken at intervals of two hours, one day, three days, five days, seven days, and fifteen days following the third spray. After the third spray on the field bean, the initial deposits of imidacloprid, which were 1.11 mg kg-1, were reduced to 0.06 mg kg-1 by the fifth day. At 1, 3, and 5 days following the last spray, respectively, residues of 0.85, 0.34, and 0.06 mg kg-1 were measured. These residues had dissipation percentages of 23.42, 76.58, and 94.59, respectively. Whereas residues were below detectable levels (BDL) and had a 100% dissipation rate 7 days after the third spray, they had not yet been detected. The initial beta cyfluthrin (Solomon 300% OD) deposits on the field bean fell to 0.06 mg kg-1 by the fifth day following the third spray. Following the prior spray, residual concentrations of 0.33, 0.19, and 0.06 mg kg-1 were detected at 1, 3, and 5 days later, respectively. But, 7 days after the third spray, all traces were gone and could not be found (BDL).

Initial deposit, Dissipation, Waiting Periods

The waiting period for safe harvest of field bean green pods when sprayed thrice with imidacloprid (betacyfluthrin + imidacloprid at 30 g a.i. ha-1) and betacyfluthrin (betacyfluthrin + imidacloprid at 30 g a.i. ha-1) were 4.12 and 7 days, respectively. This pre harvest index values are emphasizing the importance of fixing MRL’s for safeguarding the human health.

S. Srinivasa Reddy, C. Narendra Reddy and Anugu Anil Reddy (2022). Dissipation Pattern of Imidacoprid + Beta Cyfluthrin (Solomon 300 OD) on Dolichos Bean. Biological Forum – An International Journal, 14(4a): 694-700.