GROWTH OF PERENNIAL RYEGRASS - MODEL

The annual pattern of production of the perennial ryegrass crop is largely affected by the seasonal weather pattern and the change from the vegetative to the reproductive phase of growth.Analysis of the relative importance of the factors governing the growth of the reproductive crop and the regrowth of the vegetative crop is complex. Often physiological variables are correlated as well as climatic variables, which influence the physiology and morphology of the crop.Much experimental data has been collected, in the field and under controlled environments, concerning the growth of the grass crop. This information has been used to construct a mathematical model of the crop. In order to evaluate the problems of modelling the grass crop the model has been used to predict the net growth of the crop in terms of leaf, 'stem', root and dead matter using daily irradiance data. The influence of some crop characteristics on vegetative regrowth have been considered. The model has also been used to assess the relative importance, for yield, of some physiological characteristics of the reproductive grass crop. © 1979, Annals of Botany Company.