author(s)
Raj C Popat, SR Padaliya, AS Vaja, MG Borad and DJ Parmar

abstract
The present investigation deals with the critical study of population growth of cowpea aphid by using Prajneshu’s nonlinear regression model. The parameters of the model were estimated using Levenberg-Marquardt’s method. Coefficient of determination (R²), root mean squared error (RMSE) and mean absolute error (MAE) were used to examine the goodness of fit of the model. Diagnostics of residuals were carried out using run test and Shapiro-Wilk test. Prajneshu’s model described well the behavior of aphid population growth in cowpea crop.