Evaluation of Certain Insecticide Formulations for Control of Cutworms on Potato in the Nilgiris Hills.

The efficacy of several insecticides was evaluated against cutworms infesting potato in two sets of field trials at the Central Potato Research Station, Ootacamund, The Nilgiris (Tamil Nadu) dur-ing 1981–83. Aldrin 30EC (%6.00/ha), cholrpyriphos 20Ec (@2.0 1/ha) and endosulfan 35 EC (@ 1.25 1 ha) carbaryl as 50% wettable powder (@ 2.5 kg/ha) and 5% dust (@35 kg/ha), quinalphos 1.5% dust (=45 kg/ha) and phosalone 5% dust (@35 kg/ha) were tested in the first set of three trials. Dust formulations of phoxim 5%, phosalone 4%, carbaryl 5%, quinalphos 1.5% as well as 10% granules of phorate, oftanol and 5% grnules of quinllphos were applied @ 25 kgjha in the subsequent set of three trials. In the first set of trials the emulsion concentrate insecticides as well as dust for mulations reduced the tuber damage and increased the yield. Quinllphos 1.5% dust and phosalone 4% compared well with the emulsion concentrate insecticides in the profit due to protection. In the second set of trials, the dust as well as the granucular formulations significantly reduced the plant and tuber damage and increased the yield. Phorate, oftanol and phoxim also resulted in greater profit margin. Thus phorate, oftanol or quinalphos as granules and dusts of phoxiffi and quinalphos applied at the time of hoeing seem to effectively and economically reduce the damage to potato crop by cutworms.