Evaluation of Brachiaria brizantha accessions in acid soils. Rainy season

Abstract

In a low fertility acid soil, a collection of 36 accessions of the B. brizantha species was studied, with the objective of selecting the accessions of better general performance, based on some quantitative indicators, during the rainy season. The plantation was carried out in 3 x 1 m plots, without replications. The indicators studied were: plant height, leafiness, vigor, cover, affectations caused by pests and diseases, presence of chlorosis and biomass yield. For the interpretation of the results the main component analysis (MCA) and cluster analysis were used. By means of the former a high variability was detected for the first two components (77,19%); while the latter allowed to identify six different groups. The accessions, in general, were concluded to show an adequate development under the existing edaphoclimatic conditions and some of them stood out for their acceptable yield and adaptation to that environment. From the collection total, the most outstanding for these soils were: B. brizantha CIAT-2 6 64 6 , CIAT-16317, CIAT-26032, CIAT-16809, No1, CIAT-16473, CIAT-16154, CIAT-16334, CIAT-6335, CIAT-16197, CIAT-16132, CIAT-16322, CIAT-16485, CIAT-16303, CIAT-16448, CIAT-6311, CIAT-16332, CIAT-16819, CIAT-16110 and CIAT-16482. To study the material selected under grazing conditions is recommended, with the objective of determining the preommercial varieties in this environment.