CROWN RUST AND PASTURE PRODUCTION

Abstract

THERE is much information available on New Zealand's grasslands which indicates the vast difference between various theoretical plant (Mitchell, 1963) and animal (Hutton, 1963) production potentials and what is actually achieved in practice. Although these potentials are often regarded with scepticism, the fact remains that many research and demonstration farms and top farmers now produce quantities of animal products per acre which would have appeared ridiculously high a few years ago. Further, much grassland research is concerned with the identification of factors limiting the attainment of these potentials, as shown by work on treading (Edmond, 1966), nutrient cycling under grazing systems (Sears, 1953), and the optimum stage and intensity of defoliation of pasture plants (Brougham, 1961).