Estimates of potential growth of annual rye grass (Lolium multiflorum Lam.) by mathematical models

Abstract

The mathematical models for the prediction of the pastures growth present potential of use for answer scientific, agronomic and planning questions, helping in the understanding about the physiological, genetic and environment interactions, as also in the decisions of management practices and in the scenery prevision. There are several methods to calculation the potential performance, however it´s necessary correlate those more adjusted to real field conditions, in function of the diversity of biotics and abiotics factors that affect the growth and development of the plants and, consequently, in the forage yield potential performance. Among the methods evaluated for the estimate annual rye grass (Lolium multiflorum Lam.) forage potential performance, the methd proposed by Doorenbos and Kassam (1994) provided better adjusted to the field conditions, whereas the Sinclair (1993) method provided estimates of the grass growth potential, which can be obtained under extremely favorable environmental conditions and the utilization of better pasture management practices. The method of Loomis and Williams (1963) estimated a very highest productivity, and showed lower correlation with the real conditions for simulate rye grass growth potential. The acurate of the models in predict the potential performance was directly proportional to incorporates sensibility parameters that consider the prominent of abiotics and physiological phenomena involved in the biomass accumulation.