Plant respiration is the metabolic link between gross primary productivity and net primary productivity. It is also a large component of a plant's carbon budget; perhaps typically 50-70% of carbon assimilated in gross primary productivity is released back to the atmosphere as CO2 during subsequent plant respiration (Amthor and Baldocchi, 2001). Growth is the conversion of temporary pools of substrates such as carbohydrates and amides into new structures including enzymes and permanent storage such as starch in seeds. Growth includes monomer synthesis, polymerization of monomers into polymers such as cellulose and proteins, organization of polymers into organelles and cells and tool maintenance …show more content…
McCree analysis is a robust relationship and useful for an analysis of crop dry matter production. McCree's analysis has led to the recognition of two components of plant /crop respiration activity. One of these components, called the maintenance respiration component is generally related to the net weight of the plant or crop. However, it does not necessarily follow that the size of the metabolically active component of a plant or crop is related to its total dry weight. Gradually, metabolically active component of the crop becoming an increasingly smaller proportion of the total crop biomass. There may be relation between the size of the metabolically active component of the crop to the amount of light energy currently being absorbed by the crop. In turn, the amount of light energy absorbed by a crop does not increase linearly with standing crop dry weight. It approaches a maximum value with increasing leaf area index. The maintenance respiration rate is very dependent upon the temperature. Usually, for every 10 °C increase in temperature, respiration rate doubles (Q10 value) (Ryan 1991). Nevertheless, Q10 values ranges from 1.4 to 4.0 (Azcón-Bieto 1992), this is highly variable. It depends on measurement temperature, species (Larigauderie and Körner 1995), season (Stockfors and Linder 1998, Atkin et al. 2000), growth temperature (Atkin et al. 2000) and leaf metabolic state (Berry and Raison 1981). In field condition, respiration rate is a function of a plant's physiological history and is subject to acclimation, adaptation or both (Amthor 1989, Atkin et al. 2000). Moreover, the change in protein content of the plant during growth will also depend upon the growth temperature of the