Experiments were carried out on greenhouse cucumbers for studding the degradation of three insecticides i.e. carbosulfan (Marshal 25% W.P.), chlorpyrifos-methyl (Reldan 50% E.C.) and malathion (Agrothion 57% E.C.) and for estimating the residues left on fruits harvested at commercial ripening. The effects of these insecticide treatments on the total soluble solids of cucumber fruits were also studied. Analysis of fruits at intervals following application showed that the initial residue of carbosulfan (3.339 ppm) was higher than of chlorpyrifos-methyl (1.550 ppm) and malathion (0.920 ppm). These figures were decreased to undetectable (UN), 0.002 and 0.005 ppm after 12 days of spraying. The dissipation of carbosulfan was faster than chlorpyrifos-methyl and malathion. (The half-live values were 22.42, 23.79 and 27.84 hours, respectively).
The maximum residue levels (MRLs) of carboulfan (0.1 ppm), chlorpyrifos-methyl (0.5 ppm) and malathion (0.2 ppm) were reached after 6, 1 and 1 days of application, respectively.