Seasonality analysis of the tomato monthly price and its forecasting using seasonal time series models (SARIMA)

Abstract

The aim of this research is to analysis the tomato monthly prices in Baghdad province for the period (Jan 2010- Dec 2015) by using seasonal time series (SARIMA) to detect seasonal variations to be excluded from the time series. The research problem is summarized by existing seasonality phenomenon in tomato monthly prices which will be reflected on the short-term planning progress. The results showed that the appropriate and efficiency model for representing time series data for tomato monthly prices was the SARIMA model (0,1,2)(1,1,0)12. Also the results of tomato monthly prices forecasting showed a harmonic direction with the same original time series. From the obtained results, the tomato monthly prices confirm the nature of the prevailing pattern in that the tomato production was affected by the season to a large extent, as the results concluded that there is a secular trend in increasing monthly prices of tomato for the period (Jan 2016-Dec 2020), which confirmed the rise in monthly prices during the forecast period. The research recommends the need to prevent imports especially at peak time (time of crop availability in local markets), and legislating laws to protect the domestic product , in addition to taxation of imported products.