A study of the relationships between leaf area index, chlorophyll content per unit of ground area and rate of dry matter increase in a perennial ryegrass sward : a thesis presented at Massey College in part fulfillment of the requirements for the degree of Master of Agricultural Science in Victoria University of Wellington, New Zealand

Abstract

Many recent attempts to obtain a more detailed understanding of pasture growth have involved an intensive study of relationships between the rate of dry matter increase and various characteristics of the photosynthetic system. Leaf area has been widely used as a measure of the size of the photosynthetic system despite the fact that many photosynthetically active cells occur in the stalks, sheaths and petioles. Chlorophyll is essential for photosynthesis and Brougham (1960) found that there was better correlation between maximum rate of dry matter increase and the chlorophyll content per unit of ground area above the level at which 95% of the noon light was intercepted than between maximum rate of dry matter increase and leaf area index above a similar measurement level. As a logical extension of such work this thesis involves a study of the relationships between rate of dry matter increase, leaf area index and chlorophyll content per unit of ground area during the growth of a pasture.---From Introduction