A study of the effect of plant density on growth and yield in two varieties of grain barley : a thesis ... for the degree of Master of Agricultural Science

Abstract

As a thesis topic, I have chosen to work with a temperate cereal viz: Barley (Hordeum distichum) and to examine in two varieties; Zephyr and Kenias:- (1) The physiological and growth characters of two Barley varieties differing in grain yield potential. (2) The effect of plant density on growth and development and on grain yield and its components. In cereals, as in many crops, an increase in plant density leads to an increase in total dry matter until a level of yield is reached after which increase in density does not lead to a further increase in yield. The data upon which this statement is based often refers to shoot dry matter only. Grain yield on the other hand reaches a maximum with increasing density, after which a further increase in density leads to a fall in grain yield (Holliday, 1960; Donald, 1963). Crop growth, leaf area, tiller initiation and tiller death and other parameters are modified by plant density. Attempts have been made to relate these parameters with grain yield in studies envolving the physiological basis of varietal and fertilizer effects upon grain yield. Watson et al have made very full studies and have suggested that high grain yield is dependent upon having high values of leaf area and leaf area duration, especially after ear emergence (Watson, Thorne and French, 1963).[FROM INTRODUCTION]