SUMMARY :Higher atmospheric CO 2 concentration may influence positively plant production.Carbon dioxide was substrate for photosynthesis and gradient increase between the ambient air and mesophyll cells. Plants respond not only to change in surrounding CO 2 concentration, but to modifications of their microenvironment. Plants with C 4 photosynthetic pathway showed negligible photosynthetic response to elevated CO 2 because the C 4 cycle increased the CO 2 concentration in bundle sheath cells to the point where very little photorespiration occurs and calvin cycle is nearly saturated with CO 2 However, there is no consensus on the quantitave effects of increased CO 2 on plant processes and growth because of differences in response at different stages of growth, species of crops and growth limiting environmental factors. The purpose of this paper was to study the biophysical response of maize genotypes to elevated carbon dioxide and temperature regimes. The exposure of the crop elevated CO 2 and temperature regime resulted in the significant decrease in the photosynthetic rates. The minimum reduction was observed in HTMR-1, HTMR-2 and NK 6240 and the maximum in ARJUN and 900M-GOLD. Among the genotypes NK 6240, HTMR-1 and 900 M-GOLD genotype recorded maximum transpiration rate and stomatal conductance whereas, the genotypes HTMR-2 and ARJUN had the least transpiration rate and stomatal conductance. More detailed investigations are needed to complete our imagination about future consequences of possible climate variations, mainly in local level.

Hence, it is often called a "biological plough" and kalpavriksha of dry lands as all plant parts are useful. The productivity of pulses in India (640 kg ha -1 ) is far below the average

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Cotton (Gossypium sp.) is popularly known as "the white gold" and also known as king of fibre crops grown under diverse agro-climatic conditions around the world. It provides fibre, a raw material for textile industry along with cotton seed and quality animal feed and

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