Int.J.Curr.Microbiol.App.Sci (2017) 6(5): 2671-2676 2671 Original Research Article https://doi.org/10.20546/ijcmas.2017.605.299 Relationship between NDVI, LAI, fIPAR in wheat Under Reduced Solar Radiation in Delhi NCR Region Brijesh Yadav 1* , Anil Kumar Verma 2 , Sushil Kumar Kharia 1 , Avinash Goyal 1 , Ravi Kumar Meena 2 and Chiranjeev Kumawat 2 1 Divison of Agricultural Physics, 2 Division of Soil Science and Agricultural Chemistry, ICAR- Indian Agricultural Research Institute, New Delhi 110012, India *Corresponding author ABSTRACT Introduction Solar radiation is the ultimate energy source for plants to regulate the growth and development. Solar radiation reaches the Earth’s surface either as direct ray without scattering from the Sun or in diffuse form after scattering through atmospheric constituents. The sum total of the direct and diffuse radiations reaches the Earth’s surface is known as global radiation. As a consequence of increase in aerosol content, black carbon and air pollutants, light dimming or reduction in global solar radiation have become a major challenge for crop production in many areas of the world. Long-term observations confirmed that global solar radiation has a widespread declining trend in many parts of the world (Liepert, 2002 and Liu et al., 2004). India also shows a steady light dimming condition since 1960s (Wild et al., 2005 and Ramanathan et al., 2005). Many researchers have been observed that mean annual diffuse radiation is 92.6 Wm−2, with a mean standard deviation of 4.7 Wm−2 through whole Delhi (Soni et al., 2012). India International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 6 Number 5 (2017) pp. 2671-2676 Journal homepage: http://www.ijcmas.com A field experiment was carried out at the farm of ICAR-Indian Agricultural Research Institute, New Delhi during rabi season of 2014-15 and 2015-16. The study was conducted to observe response of wheat under reduced solar radiation. In this experiment, three wheat cultivars namely, HD 2967, WR 544 and PBW 502 were grown under five solar radiation reduction treatments i.e. R1 (control), R2 (20% shading), R3 (35% shading), R4 (50% shading) and R5 (75% shading) levels. Ground held spectroradiometer was used for spectral reflectnance measurement of wheat canopy. Finally normalized difference vegetation index (NDVI) was calculated for different treatments. The different regression equations between LAI -NDVI and fIPAR-NDVI were developed for different treatments for both years. The positive correlations were observed for all treatments during both years. Spectral radiance of blue band (400-500nm) was more inside the severe shading compared to mild shading and control. But spectral radiance of red band (620-700nm) was less inside the severe reduced radiation treatments in both the seasons. Keywords Wheat, Shading, Soil moisture, Spectral radiance, NDVI. Accepted: 25 April 2017 Available Online: 10 May 2017 Article Info