The effects of nitrogen fertiliser and irrigation on some determinants of economic yield of Kopara wheat: A dissertation submitted in partial fulfilment of the requirements for the Degree of Bachelor of Agricultural Science (Honours) in the University of Canterbury

Abstract

Many factors have been studied with regard to the nature of the physiology of grain yield in cereals; the assimilation, movement, and partition of assimilates have proved to be the most important aspects. Thus, the distribution of dry matter within the plant and, more importantly, the governing physiological mechanisms in relation to the environment have now become focal points for further research. Progress in these directions may be expected to lead to a clearer definition of yield determination and of genotypic differences. The effects of the applications of nitrogen fertiliser and water on the biological and economic yields of cereal crops have been well documented. However. evidence of how these treatments affect the organs of the plant which are primarily involved in the determination of the economic yield of a crop is less abundant. Because of this, the experiments described here were carried out with the aim of measuring the effects of nitrogen fertiliser and irrigation on two such plant characters; flag leaf area and ear weight. These were chosen because previous work indicated that, on any individual tiller, there was an important relationship between these two parameters. Thus, the aim here was to see how nitrogen and water affect each of these factors individually and any relationship which exists between the two plant characters. The results for this paper were obtained from a trial carried out by the Plant Science Department, Lincoln College, in which the effects of nitrogen fertiliser and irrigation on a wide variety of aspects of the growth of a new wheat cultivar, Kopara, were investigated.