ABSTRACT
Photosynthesis is the basic process underlying plant growth and production of food, fuel, and fiber required to sustain life (Tolbert, 1997). An understanding of photosynthesis is therefore necessary to appreciate processes that determine yield in agriculture, forestry, ecology, and many other fields. This most important biochemical process in green plants, which literally means building by light, prob ably evolved 3500 million years ago (Shopf, 1993). In general, pho tosynthesis is the process by which plants synthesize organic com pounds from inorganic substances using light. During photosynthesis, C from atmospheric carbon dioxide (CO2) is fixed to become part of many organic molecules that constitute plant tissues. Because of this, total dry matter production of crop plants is correlated with photo synthetic rates integrated over plant growth cycles. Yield is related to total dry matter for many plants, especially associations with harvest index (see Chapter 3).
