Light photosynthetic efficiency

The acquisition of carbon is strongly modulated by the surface area of photosynthesizing leaves hence, understanding leaf area development is germane to efforts to increase yield. In many crops, biomass is linearly related to the amount of light intercepted (Monteith, 1977). This is certainly the case for Jerusalem artichoke, where total productivity is strongly correlated with the amount of solar radiation intercepted (Denoroy, 1996 Meijer et al., 1993). Leaf area, leaf duration, and photosynthetic efficiency of the crop canopy determine how much light is intercepted and subsequently utilized (Table 10.9). 

Fig. 3. Maximum theoretical photosynthetic light conversion efficiency of water to H2 using sunlight. The arrows indicate efficiency losses at various stages after photosynthesis starts, and the remaining efficiency at each stage is indicated as a percentage.

A measure of photosynthetic efficiency and productivity can be obtained from the light-saturation curve of photosynthesis. This type of analysis is necessary and sufficient for the measurement of the vital signs of photosynthesis [Melis et al. 1999], In such measurements, the rate of O2 evolution, when plotted as a function of irradiance, first increases linearly and then levels off as the saturating irradiance (Is) is approached [Neale et al. 1993]. The slope of the... 

Other factors that influence the phytoplankton stock cannot be addressed here. Gargas et al. (1978) concluded from the restricted influence of light, temperature, and nutrients on the photosynthetic efficiency that phytoplankton growth is modified by the different individual physiological behavior and the different grazing pressure. 

---