Potato Journal

Field trials were conducted for testing the comparative efficacy of seven insecticides against potato tubermoth, Phthorimaea operculella (Zeller), in four crop seasons during 1975 to 1977 at Central Potato Research Station, Rajgurunagar. The results of these trials indicate that four insecticides viz., chlorfenvinphos, quinalphos, leptophos and acephate, respectively, @ 0.4, 0.5, 0.68 and 0.5 kg a i. per ha are highly effective in reducing the population of tuberworm and foliage and tuber damage in the crop. Other three insecticides viz., dicrotophos, carbaryl endosulfan @ 0.5, 2.0 and 1.0 kg a.i./ha, respectively, are also fairly effective against the pest. The insecticides should be applied as soon as the first appearance of the pest is seen in the crop and treatments may be repeated at fortnightly intervals depending on the persistence of infestation.