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In order to determine the agronomic performance of six accessions belonging to four species from the Brachiaria genus, a study was conducted during a year (rainy and dry seasons). The plant height was measured; likewise, leafiness, vigor and cover, affectations by phytophagous insects and pathogen microorganisms, chlorosis and biomass yield, were estimated. Principal component analysis (PCA) and cluster analysis were applied to the results, through the statistical package SPSS version 11.5. The total variance was high (higher than 90 %) for both seasons, related to the measured and/or estimated variables. The variables with the highest variability were height, affectations by pathogenic microorganisms and yield; in addition to leafiness, cover and vigor. An integral analysis allows to conclude that the accessions Brachiaria decumbens and Brachiaria brizantha CIAT-16322 stood out during the evaluation, for coinciding in both seasons. Their insertion in the flow of varieties is recommended, in order to obtain a commercial variety to be used in animal husbandry systems, in zones with predominance of moderate-fertility soils. [ABSTRACT FROM AUTHOR]

In order to determine the agronomic performance of six accessions belonging to four species from the Brachiaria genus, a study was conducted during a year (rainy and dry seasons). The plant height was measured; likewise, leafiness, vigor and cover, affectations by phytophagous insects and pathogen microorganisms, chlorosis and biomass yield, were estimated. Principal component analysis (PCA) and cluster analysis were applied to the results, through the statistical package SPSS version 11.5. The total variance was high (higher than 90 %) for both seasons, related to the measured and/or estimated variables. The variables with the highest variability were height, affectations by pathogenic microorganisms and yield; in addition to leafiness, cover and vigor. An integral analysis allows to conclude that the accessions Brachiaria decumbens and Brachiaria brizantha CIAT-16322 stood out during the evaluation, for coinciding in both seasons. Their insertion in the flow of varieties is recommended, in order to obtain a commercial variety to be used in animal husbandry systems, in zones with predominance of moderate-fertility soils. [ABSTRACT FROM AUTHOR]

The objective of the study was to make the morphobotanical characterization of a group of Cenchrus purpureus plants, from a collection carried out under field conditions in two geographical zones of Cuba, on a Ferralitic Red soil. Eight quantitative and seven qualitative traits were evaluated, in two phenological phases: vegetative and reproductive. The variability in this collection was determined through a principal component analysis (PCA). The quantitative descriptors with higher variability were the number of internodes, limbo length and width, length of the leaf sheath and vegetative height. Among the qualitative descriptors, all the plants had erect growth habit and inflorescence shaped as a spiciform panicle; the color of the leaf parts was generally green, just like that of the stem, although the plants with keys 603 and 607 showed maroon shades. In the accessions no hairs were observed on the underside of the leaf limbo, but they were observed on the bundle, which is characteristic of the species. It is concluded that the evaluated material has high variability in several quantitative descriptors, which should be taken into consideration in future research about the breeding and selection of this species for its inclusion in animal husbandry systems. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the structural and floristic composition performance of 19 accessions of Urochloa brizantha, associated with Stylosanthes guianensis CIAT-184 on an acid soil, after three years of simulated grazing. The variables live shoots-dead shoots ratio and floristic composition were analyzed. The measurements were made in all the rotations during the experimental period. The substitution of dead shoots was favorable in most of the treatments; four accessions stood out (CIAT-16322, CIAT-26646, CIAT-16332 and CIAT-16335) in which, at the end of the period, the index of substitution of dead shoots was over two. From the accessions, 36,6% reached a percentage higher than 80% at the end of the experimental period; the accessions CIAT-16317, CIAT-16335 and CIAT-16332 were the ones with higher presence of the base pasture (> 90%). In all the associations the legume was represented in a low percentage (< 16%); while the weeds remained, in most cases, below 20%. In general, the evaluated U. brizantha accessions showed an acceptable persistence or stability in time, and CIAT-16322, CIAT-26646, CIAT-16332 and CIAT-16335 stood out. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the structural and floristic composition performance of 19 accessions of Urochloa brizantha, associated with Stylosanthes guianensis CIAT-184 on an acid soil, after three years of simulated grazing. The variables live shoots-dead shoots ratio and floristic composition were analyzed. The measurements were made in all the rotations during the experimental period. The substitution of dead shoots was favorable in most of the treatments; four accessions stood out (CIAT-16322, CIAT-26646, CIAT-16332 and CIAT-16335) in which, at the end of the period, the index of substitution of dead shoots was over two. From the accessions, 36,6% reached a percentage higher than 80% at the end of the experimental period; the accessions CIAT-16317, CIAT-16335 and CIAT-16332 were the ones with higher presence of the base pasture (> 90%). In all the associations the legume was represented in a low percentage (< 16%); while the weeds remained, in most cases, below 20%. In general, the evaluated U. brizantha accessions showed an acceptable persistence or stability in time, and CIAT-16322, CIAT-26646, CIAT-16332 and CIAT-16335 stood out. [ABSTRACT FROM AUTHOR]

A collection of 19 Urochloa brizantha accessions was studied, in association with Stylosanthes guianensis on a soil characterized by acidity, in order to select the best ones for this soil type. The measured and estimated variables were: vegetative height, availability and non-consumed pasture residue. In addition, leafiness, cover, vigor, CP content, fiber (NDF and ADF) degradation and IVDMD, were determined. The interpretation of the results was done through principal component analysis; and for grouping the associations and selecting those that had similar characteristics, cluster analysis was used. The existence of a high accumulated variability (75,9%) was detected in the first four components. When analyzing the agronomic and nutritional value performance, after three years of exploitation, the formation of six groups was identified; the associations in which the accessions that form group II were present (CIAT-16335 and CIAT-26646) stood out, reaching the highest values in height, availability and utilization, as well as high vigor and high CP contents and IVDMD. These associations that included the accessions that belonged to group II (CIAT-16335 and CIAT-26646) were present showed the best performance, when making an overall analysis of agronomic and nutritional value variables. It is recommended to study structural and floristic composition variables, as well as the seed production potential, in order to propose a pre-commercial variety for the agroecosystems with acid soil. [ABSTRACT FROM AUTHOR]

The objective of this paper is to facilitate the understanding about the relevance of the actors' perceptions for social change and sustainability of the transformations that are executed in the municipal agricultural sector, in the face of the complexity of current scenarios. The analysis and reflection are derived from the experience obtained during more than 15 years of field work, with tools that promote participation and interdisciplinarity in the analyses, by the research line of Agricultural and Sustainable Local Development of the Pastures and Forages Research Station Indio Hatuey, in agroproductive entities, municipalities and localities, with the contribution of their key actors. For the study the information regarding the officials, workers and decision makers' perceptions were considered; statistical documents associated to the agricultural productions of the territories were also analyzed. As a result it was observed that the established institutionality should be reformed, because it slows down the concretion of the transformation projects and actions. From this, it can be concluded that the knowledge and understanding about the analyzed actors' perceptions at municipal-local level remarkably limit that the projection and implementation of the changes are favorably visualized. [ABSTRACT FROM AUTHOR]