Agronomic and nutritional value evaluation and selection of accessions of Brachiaria brizantha (Hochst. ex A. Rich.) Stapf on acid soils

 

Yuseika Olivera Castro
Estación Experimental de Pastos y Forrajes Indio Hatuey Central España Republicana 44280, Matanzas, Cuba

 

ABSTRACT
In order to evaluate accessions of Brachiaria brizantha (Hochst. ex A. Rich.) Stapf and thus select the most outstanding ones on acid soils, trials were developed corresponding to the first two phases of the varietal flow. The data were interpreted through Principal Component Analysis, Cluster Analysis and Variance Analysis. In phase I, under cutting system during a year, 36 accessions were included, and with the use of seven variables 19 were selected, which represented 52,8 % of the initial collection. They were inserted in phase II, in a grazing system and associated with Stylosanthes guianensis (Aubl.) Sw. CIAT-184, in which this material was evaluated through the joint evaluation of 13 agronomic variables and nutritional value variables as novel aspect. After three years the associations that formed one of the clusters were selected, represented by B. brizantha CIAT-16335 and CIAT-26646. These associations reached availability values of 3,72 t DM/ha/rotation; 64,04 % of utilization by the animals; 11,22 % CP; 65,19 % IVDMD; a LS/DS ratio higher than 2,25; a population higher than 80,0 % and incidence of weeds lower than 4,0 %. These results allowed to propose them as pre-commercial varieties for soils characterized by acidity and recommend their insertion in the varietal flow in order to document the essential complementary information for their selection as commercial variables.