The MATERIALS EMPLOYED in the present research investigations were a field-grown crop of cotton and 4 different spray schedules. The TRIALS were, however, laid out at the Ayub Agricultural Research Institute, (AARI), Faisalabad in a Randomized Complete Block Design (RCBD) and there were, thus, five treatments including a control, having three repeats each. The SPRAY MATERIALS were prepared on V/V basis, and sprayed over to the crop at an interval of fortnight starting from August, 2010 by means of a Solo-Knapsack sprayer. The various observations on the population of cotton jassid during the trials were kept on being taken continuously throughout the test season. The data on the population of jassid, from each plot were recorded early in the morning one, two , three and seven days after the application of the insecticides, from five plants, selected at random. For this purpose, one leaf each from the upper portion, from the middle portion and from lower portion, were observed for jassid population, till five plants were completed. The population data were, however, finally presented in the form of mean values separately for each repeat of the various test treatments.