Wheat yield estimation using landsat images and field observation: A case study in Mashhad

Remote sensing is one of the techniques recently used for the purpose of monitoring and predicting crop yield. The objective of this study was predicting wheat yield in Mashhad during 2009 and 2010 by Landsat (TM) and (ETM+) images with ground based data. For this purpose, three images dated 6, 14 and 22 Jun 2009 and 8 and 24 May and 9 Jun 2010 were analysed and vegetation indices were computed. Field data included wheat growth stage, yield and geographical position. Results showed that the best relation between yield and indices were obtained in 14 Jun 2009 and 14 May 2010. These dates coincided with milky and maturity stages of wheat. Cumulative indices estimated yield prediction more precisely than others indices. Red band had the highest correlation (r2=0.76) with yield among the other band. Through the other indices, PD311 and PD312 had the best correlation with the yield. Correlation between NDVI and yield was not significant. The best correlation with the yield was obtained by applying the multi linear regression method (r2=0.83).