Response and stability in lovegrass cultivars (Eragrostis curvula (Schrad.) Nees) under controlled environmental conditions

To infer the implantation capacity of ten cultivars of the apomictic species Eragrostis curvula (Schrad.) Nees s. lai. corresponding to Curvula, Conferta, Robusta and Pilosa types, the response (b) and stability (S-d(2)) of germination capacity and initial growth were evaluated. Two experiments were carried out. In one of them the germination percentage was registered and in an another one the initial growth was evaluated by measuring the green and dry matter weight of aerial biomass. Also it was established the possible relationships among the calculated statistics. The environmental conditions were wide enough to have an adequate estimation of environmental indices and regression coefficients. The linear genotype-environment interaction was highly significant for the three characters. The Curvula type cultivars, with a greater efficiency in water use, exhibited superiority at initial growth while Conferta type presented genotypes specifically adapted to unfavourable environments. Cv. Don Eduardo, (Robusta type) showed the highest adaptability to all environments. There was non-association between the means and the regression coefficients of the different genotypes as to germination capacity; however, for aerial biomass yield, the genotypes with a production above the mean had regression coefficient values over unity. In general, it was also observed that the same genotypes exhibited different relationships among the mean and the regression coeffient depending on the character analysed.