Estimación de la producción de materia seca y dinámica del crecimiento vegetativo de tres gramíneas en el sur de Coahuila, México

Abstract

The species love grass (Eragrostis interrnec1ia Hitchc.), tall fescue (Festuca arundinacea Schreb.) and orchard grass (Dactylis glomerata L.) were evaluated in order to assay the dynamic of vegetative growth and to generate a model to estimate dry matter starting from leaf lamina elongation, number of shoots per plant, and heat units accumulated and a model to predict leaf lamina elongation starting from the heat units accumulated. The models for estimating the dry matter production in love grass and tall fescue were generated considering elongation values of leaves as an independent variable (Yi β1Xi+εi), while in D. glomerata the inclusion of the variable number of shoots per plant was included (Yi β0+β1 X1i+β 2 X2i+εi). To estimate dry matter starting from accumulated heat units, the simple lineal model Yi=β 0+β1Xi + εi was generated. For estimating lamina elongation starting from heat units, significant determining coefficients from 0.42 to 0.57 were found through the model Yi=β 1Xi +εi . The summer growth values shows differences in dynamic leaf growth among species. The appearing rate of leaves was better in summer. In weight proportion lamina: sheath + stem during the summer, orchard grass was slightly superior to tall fescue and love grass; meanwhile in winter the dry matter yield resulted from the leaf laminas.