PREHARVEST WHEAT YIELD AND PRODUCTION ESTIMATION FOR THE PUNJAB, INDIA

Two different approaches to relate wheat yield with spectral indices d erived from remotely-sensed data have been explored for the state of P unjab, India. In the study based on site-level approach yield obtained from crop-cutting sites was found to be linearly related to NIR/Red r atio derived from Landsat MSS data of corresponding sites in Ludhiana and Patiala districts of Punjab. Incorporation of agrometeorological d ata was also tried. Certain inherent limitations of the site-level app roach led to the district-level studies which focused on the relation of district yields with corresponding average spectral indices derived from satellite sensors like Landsat MSS and IRS-LISS-I. Significant c orrelations were observed in all cases and the relation based on Lands at MSS/IRS LISS-I data was used for trial forecast of wheat yields for 1989-90 season. A comparison of remote-sensing based production forec ast showed good agreement with the conventional estimate of Bureau of Economics and Statistics at state level although at district level, de viations were larger.