The effect of water stress on crop is seen to be 
spectrally apparent, Green leaf area index data is one of the 
basic state or system level variables for primary production, In 
most instances leaf area index and its duration provide measure of 
net assimulation rate and accumulation of phytomass for a given 
variety, The knowledge of harvest index between phytomass and 
grain could be utilised for estimating grain yield. 
The chlorophyll content of the plant is considered to be 
an important indicator of the crop conditions. The correlation 
between biomass and the spectral parameters again lead to a 
possible means of remotely monitoring terrestrial vegetation bio- 
mass or phytomass, The role of the phytomass in the global CO2 
cycle is extremly important and involves the amount of carbon 
stored in various plant communities of the world; with special 
emphasis on forest areas and in particular, tropical forests 
(Atjay et al 1979, Bolin et al 1977, Woodwell 1978). 
The strong correlation between the plant physiological 
and various spectral parameters provides a basis to assess the 
leaf area index, chlorophyll content and biomass of the plants 
from remotely sensed data. These data monitored through time and 
combined with other types of data (Soil, Water,Climatic etc.) 
offer the potential to nondestructively monitor the growth 
condition of the crop and its development, 
REFERENCES 
1. Atjay, G,L., Detner, P. and Durigneaud, P. 1979, Terrestrial 
primary production and phytomass., In s: Global Carbon dioxide 
cycle, chapter 5, SCOPE Report No, 13, John Wiley and Sons, 
New York. 
2. Arnon D,I, 1949, Copper enzymes in isolated chloroplasts : 
Polyphenol oxidase in Beta Vulgaris. Plant Physiology 11; 1-10. 
3. Bolin, B (1977), Changes of land biota and their importance for 
carbon cycle. Science 196 : 613-15. 
4. Colwell, J.B., Rice D.P, and R,.F,Nalepka, 1977. Wheat Yield 
forecast using Landsat data. In proc. of 11th International 
Symposium on Remote Sensing of Environnent, University of 
Michigan, Ann Arbor, pp. 1245-1254. 
5. Holben, B.N., CJ., Tucker and C.J. Fan, 1980 + Spectral 
assessment of soyabean leaf area and leaf biomass.  Photogram. 
Engg. and Rem. Sens. 46 (5) : 651-656. 
6. Tucker, C.J. 1979. Red and photographic infrared linear 
combinations for monitoring vegetation,  Hemote Sensing of 
Environ. 8 (29) : 127-150. 
7, Tucker, C.J., J,H.Elgin, J.B. MoeMurtrey and C,.J,Fan. 1979. 
Monitoring Corn and Soyabean crop development with hand held 
radiometer spectral data. Remote Sensing Enviroment 8 (2) 3 
237-248, 
1021