Photonirvachak Journal of the Indian Society of Remote Sensing, Vol. 29, No. l&2, 2001 Relationship of Wheat Grain Yield with Spectral Indices SOM PAL SINGH*, O P BISHNOI, RAM NIWAS AND MAHENDER SINGH *Regional Station PAU Bhatinda Department of Agricultural Meteorology CCS Haryana Agricultural University Hisar- 125004, India Introduction Crop identification and prediction of yield are the main concern of remote sensing application in agriculture. Crop canopies are dynamic entities influenced by many management practices including cuitivars, seeding rate, soil moisture, fertilizers and disease, etc. in addition to architecture of the crop (Rao et al., 1.997). The knowledge of these factors is required for monitoring crop growth and evaluating productivity. Using remote sensing technology more accurately. Spectral response study for acreage estimation of wheat has been made in Haryana (Dadhwal et al., 1991) but the spectral vegetation indices in relation to Recd. 12 May, 2000; in final form 15 Sept., 2001 yield of wheat in varying environments under Hisar condition is lacking. The present study is an attempt to study the relation of vegetation indices with yield. Methodolgoy A field experiment was conducted during the Rabi seasons of 1996-97 and 1997-98 at the Research Farm, Choudhary Charan Singh Haryana Agricultural University, Hisar. The experiment was planned under three dates of sowing - early (October 28), normal (November 22) and late (Decemberl7); two moisture levels: l~-first moisture level (one irrigation at Crown Root Initiation) 12-second moisture level (four irrigations at CRI, jointing, anthesis and dough stage) and four nitrogen levels (N0-No nitrogen,