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The initial performance of the simultaneous association between high sowing density of tree species and Cuba CT-115 (Pennisetum purpureum) was characterized through a random blocks design with a factorial arrangement (4 x 5) and four replications. Factors were determined by treatments and growth from 15 to 75 days old: T1) alternate furrows of CT-115 - leucaena (Leucaena leucocephala) cv. Peru; T2) CT-115 - leucaena - CT-115 - gliricidia (Gliricidia sepium); T3) CT-115 - leucaena- CT-115 - moringa (Moringa oleifera) and T4) CT-115 -leucaena - CT-115-caesealpinia (Caesealpinia platyloba). Results showed interaction for all variables corresponding to trees. The highest number of plants m-¹ (P ≤ 0.001) corresponded to moringa at 45 d from sowing (8.65) and it did not differ from leucaena at 60 d. The lowest population (P ≤ 0.001) was shown in leucaena at 15 d, without differences from gliricidia, except at 15 d. Moringa reached the highest height (P ≤ 0.001) with 104.69 cm at 75 d. The lowest height was found in leucaena at 15 d with a mean value of 3.71 cm. Leucaena showed the lowest insertion values of the first branch (P ≤ 0.001), while moringa reached 30.35 cm long. In CT-115, there were no differences among treatments, only among growth ages. It can be concluded that moringa had the best performance during the initial development stage in the simultaneous association with CT-115. [ABSTRACT FROM AUTHOR]

The initial performance of the simultaneous association between high sowing density of tree species and Cuba CT-115 (Pennisetum purpureum) was characterized through a random blocks design with a factorial arrangement (4 x 5) and four replications. Factors were determined by treatments and growth from 15 to 75 days old: T1) alternate furrows of CT-115 - leucaena (Leucaena leucocephala) cv. Peru; T2) CT-115 - leucaena - CT-115 - gliricidia (Gliricidia sepium); T3) CT-115 - leucaena- CT-115 - moringa (Moringa oleifera) and T4) CT-115 -leucaena - CT-115- caesealpinia (Caesealpinia platyloba). Results showed interaction for all variables corresponding to trees. The highest number of plants m-1 (P ≤ 0.001) corresponded to moringa at 45 d from sowing (8.65) and it did not differ from leucaena at 60 d. The lowest population (P ≤ 0.001) was shown in leucaena at 15 d, without differences from gliricidia, except at 15 d. Moringa reached the highest height (P ≤ 0.001) with 104.69 cm at 75 d. The lowest height was found in leucaena at 15 d with a mean value of 3.71 cm. Leucaena showed the lowest insertion values of the first branch (P ≤ 0.001), while moringa reached 30.35 cm long. In CT-115, there were no differences among treatments, only among growth ages. It can be concluded that moringa had the best performance during the initial development stage in the simultaneous association with CT-115. [ABSTRACT FROM AUTHOR]

Results of studies conducted in the Institute of Animal Science of the Republic of Cuba with an integral and multidisciplinary approach are presented. The topic developed is related with the applied strategies to control the degradation of grasslands invaded by wire grass (Sporobolus indicus). Other researches conducted with this weed in different tropical and subtropical regions considering the biological characteristics of this species are also considered. Reproduction methods of wiregrass and of seeds production are also dealt with. The negative effect of this weed on the economy and biomass production of an improved grassland is analyzed. The infestation level of wiregrass and the pureness percentage of the improved pasture are considered, as well as the application of recovery alternatives throughout new sowings or rehabilitation. It is proved that planting species of the Pennisetum genus by the plowing method or the traditional method are effective ways of control that also favor the recovery of completely damaged grasslands. The recovery or rehabilitation with the use of plowing plus harrowing, in combination with the chemical and organic fertilization, is a promising alternative to recover the energy of the grassland and an option to minimize the population of this weed and reestablish the productivity of the agroecosystem. A good animal and agrotechnical management is suggested after these labours, in order to achieve the sustainability of the improved pastures. The knowledge described will make possible to design a program for the integral control of the weed and the recovery of improved grasslands ecosystems invaded by wiregrass. [ABSTRACT FROM AUTHOR]

En un suelo ferrálico cálcico, mediante un diseño completamente aleatorizado y diez repeticiones, se estudió la influencia de la población (0, 2, 4 y 6 plantas/m2) de espartillo (Sporobolus indicus. L) en el rendimiento, costo y calidad de la biomasa de hierba guinea (Panicum maximum Jacq vc Likoni). La altura del espartillo no varió con el aumento de su población y el área de suelo cubierto se incrementó (P < 0.001). Hubo relación inversa (r = -0.88, P < 0.001) entre el rendimiento de guinea y la población de espartillo. El costo del forraje se incrementó de 25.21 a 78.63 pesos, para 0 y 6 plantas de espartillo/m2, respectivamente. La composición química del suelo no varió con los tratamientos. La mayor población de espartillo produjo menor (P < 0.05) digestibilidad de la materia orgánica (DMO) y de Ca (P < 0.01). No hubo efecto en la composición química de guinea. En el espartillo, solo la PB y el P fueron menores (P < 0.01) con el aumento de su población. Se concluye que el incremento de la población de espartillo disminuyó el rendimiento de guinea, elevó el costo de producción de la biomasa y alteró algunos indicadores de calidad del forraje. Se recomiendan estudios que profundicen en los posibles efectos de la población de espartillo en la calidad de la biomasa de los pastos mejorados. [ABSTRACT FROM AUTHOR]

The influence of wire grass (Sporobolus indicus. L) (0, 2, 4 and 6 plants/m²) on yield, cost and quality of Guinea grass (Panicum maximum Jacq cv. Likoni) biomass was studied in a calcic ferralic soil, through a completely random design and ten repetitions. The wire grass height did not vary with the increase of its population and the area of the soil covered was increased (P < 0.001). There was an inverse ratio (r = -0.88) (P < 0.001) between Guinea grass yield and wire grass population. The forage cost increased from 25.21 to 78.63 pesos, for 0 and 6 plants of wire grass/m², respectively. The chemical composition of the soil did not vary with the treatments. The highest wire grass population produced lower (P < 0.05) content of organic matter digestibility (OMD) and Ca (P < 0.01). There was no effect on the chemical composition of Guinea grass. In the wire grass, only CP and P were lower (P < 0.01) with the population increase. It is concluded that the increase of wire grass population diminished the Guinea grass yield, elevated the cost of biomass production and altered some indicators of forage quality. Further studies on the possible effects of wire grass population on biomass quality of improved pastures are recommended. [ABSTRACT FROM AUTHOR]

Se evaluó el control del espartillo (Sporobolus indicus) mediante la renovación de un pastizal mejorado en estado de degradación, con 50 % de espartillo y 20 % de guinea, a partir de la utilización de variedades del género Panicum. Los tratamientos fueron: siembra de guinea Likoni, Común, Mombaza, Tanzania y rotura sin siembra. Se caracterizó el comportamiento de los tratamientos mediante análisis univariado y multivariado. Se constató que las variedades Likoni y Mombaza ejercieron mejor control del espartillo. A medida que se incrementó la dominancia de guinea, tanto en la variedad Likoni como en Mombaza, fue menor la densidad poblacional de espartillo. La disponibilidad de biomasa tuvo un comportamiento similar en ambas, con relación a la dominancia de esta arvense. El porcentaje de guinea fue superior a 60 %, incluso en la rotura sin siembra, con respecto al muestreo inicial de la vegetación. No obstante, el mayor porcentaje del pasto mejorado se encontró en Likoni y Mombaza. Las variedades Tanzania y Común ejercieron menos control del espartillo, o muy similar a la rotura sin siembra. Se concluye que los cultivares Likoni y Mombaza ejercieron mayor control del espartillo. El análisis multivariado permitió establecer la relación entre variables, y explicar integralmente los resultados de la renovación. Se recomienda la utilización de las variedades Likoni y Mombaza, como alternativa para el control del espartillo en pastizales mejorados en estado de degradación. [ABSTRACT FROM AUTHOR]

The control of wiregrass (Sporolobus indicus) was assessed by the renewal of an improved pasture in state of degradation, with 50 % of wiregrass and 20 of Guinea grass, using varieties of the Panicum genus. The treatments were: Guinea grass Likoni, Common, Mombaza, Tanzania and tillage without sowing. The performance of the treatments was characterized through univariate and multivariate analyses. It was proved that Guinea grass Likoni and Mombaza had better control of wiregrass. As the prevalence of the Guinea grass for both varieties Likoni and Mombaza was increased, the population density was lower in wiregrass. The biomass availability was similar in both, in respect to the prevalence of this weed. The percentage of Guinea grass was superior to 60 %, even in the tillage without sowing, in respect to the initial vegetation sampling. However, the highest percentage of the improved pasture was found in Likoni and Mombaza. The Tanzania and the Common varieties exerted lower control in wiregrass, or quite similar as to that of the tillage without sowing. It is concluded that the Likoni and Mombaza cultivars controlled wiregrass much more. The multivariate analysis allowed establishing the relationship between the variables, and explaining integrally the results of the renewal. The use of the Likoni and Mombaza varieties as alternative for controlling wiregrass in improved pastures in state of degradation is recommended. [ABSTRACT FROM AUTHOR]

The invasion or infestation of undesirable plants in rangelands is one of the main consequences of the degradation of the improved rangelands. This paper provides the fundamental aspects to be considered for developing a comprehensive management program of the most common invasive plants in Cuban cattle areas: diagnosis, historic sequencing of the most significant plants and indicators (density, frequency of species appearance, among others). The knowledge of the biology and ecology of these plants is added as outstanding element. Also, reference is made to the economic impact of weeds on sown rangelands. [ABSTRACT FROM AUTHOR]

En un pastizal de Panicum maximum vc. Likoni (guinea), en suelo ferrálico cálcico de mediana fertilidad, se utilizó un diseño de muestreo. El área se dividió en cuadrículas de 625 m2 para determinar la homogeneidad y el tamaño de la muestra, con el propósito de caracterizar, desde el punto de vista biológico, la especie Sporobolus indicus (L.) R. Br (espartillo). Las variables en estudio fueron: rendimiento de materia seca (MS), perímetro de la macolla y número de plantas/m2 de espartillo. Se aplicó la prueba de Bartlett para determinar la homogeneidad de varianzas entre todas las cuadrículas y las cuadrículas 1, 3, 5 y 2, 4, 6, respectivamente. Una vez que se determinó la prueba de homogeneidad, se procedió a prescribir el tamaño de muestra, mediante el paquete estadístico INFOSTAT (2001). El tamaño de muestra para el rendimiento de MS fue de 18, el perímetro de la macolla 19 y 16 el número de plantas/m2 , respectivamente. Por tanto, se consideró una muestra óptima de 20 plantas para caracterizar el comportamiento biológico del espartillo en un agroecosistema de guinea. [ABSTRACT FROM AUTHOR]

En este estudio se ofrecen los conceptos de degradación y recuperación de pastizales. También aparecen las principales causas de la degradación de los pastos mejorados en las regiones tropicales y subtropicales. Se analizan y proponen métodos para la recuperación de los pastos degradados. Se analizan soluciones mediante la aplicación de labores mecánicas, fertilización, la quema, el control de malezas y otros métodos efectivos para la rehabilitación de pastizales. Se realizan recomendaciones prácticas para técnicos y productores de alternativas posibles para detener el deterioro de los pastos y se ofrecen elementos económicos de la magnitud de este fenómeno en Cuba, el trópico latinoamericano y el mundo. [ABSTRACT FROM AUTHOR]

This paper deals with the concepts of degradation and recovery of grasslands. Also, it presents the main causes of degradation of the improved pastures in tropical and subtropical regions. Methods for the recovery of the degraded grasslands are analyzed and proposed. Solutions are analyzed through the application of mechanical labours, fertilization, burning, weeds control and other effective methods for grassland rehabilitation. Practical recommendations of possible alternatives to halt the deterioration of pastures are made for technicians and farmers and economic elements of the magnitude of this phenomenon in Cuba, the Latin American tropics and the world are offered. [ABSTRACT FROM AUTHOR]

En un pastizal degradado de Panicum maximum Jacq (guinea likoni), con más de 58 % de invasión de Sporobolus indicus L R. Br (espartillo), se comparó el efecto del momento de iniciar la preparación del suelo (aradura) en el establecimiento de Pennisetum purpureum cv Cuba CT-115, el control de espartillo y la producción de biomasa de CT-115, así como en su validación técnico económica en condiciones de producción. Los tratamientos consistieron en realizar la aradura en abril, mayo y junio. El CT-115 se plantó a vuelta de arado en junio, después de un pase previo de grada media. Los indicadores evaluados en el espartillo fueron: plantas/m² y composición botánica; en el CT-115 se midió el número de yemas basales y laterales/m², la altura, el rendimiento y el costo/t de MV y MS producida. El mayor número de plantas/m² de espartillo se observó cuando se realizó la labor de aradura en junio. Se produjo un decrecimiento desde 7-8 plantas/m² a valores inferiores de 1.7 plantas/m², después de aplicar los tratamientos y plantar el CT-115. Similar comportamiento tuvo el porcentaje de espartillo, que fue 53-68 % antes de plantar el CT-115 y disminuyó a valores inferiores de 7 %. En este tratamiento la hierba guinea se incrementó al iniciar la labor de aradura en abril y mayo. El número de yemas basales (30) y laterales (90/m²) fue mayor (P < 0.001) en el CT-115 cuando se plantó después de realizar la aradura en abril. La mayor altura de CT-115 tuvo lugar cuando la aradura se efectuó en abril y mayo (262-272 cm). En los dos muestreos realizados, el mayor rendimiento (9.22-9.49 t/ha MS) se alcanzó cuando la labor de aradura se hizo en abril. En este tratamiento se obtuvo el menor costo/t MS producida (4.21 y 14.43 pesos cubanos), respectivamente. Se concluye que la mayor producción de biomasa y menor (P < 0.1) costo/t de MV y MS, se logró cuando la aradura se realizó en abril. Cuando se utiliza esta tecnología, se reduce la población de espartillo a niveles que se hallan por debajo del umbral crítico de esta maleza en pastizales de CT-115. Además, disminuyen los costos de plantación y establecimiento. [ABSTRACT FROM AUTHOR]

The effect of the initiation time of the soil preparation (plowing) on the establishment of Pennisetum purpureum cv Cuba CT-115, the control of wiregrass and the biomass production of CT-115, as well as the technical-economical validation in production conditions were compared on a degraded grassland of Panicum maximum Jacq (guinea grass) with more that 58 % of invasion of Sporolobus indicus L.R. Br. (wiregrass). The treatments consisted of plowing in April, May and June. The CT-115 was planted using the plowing method after a previous harrowing. The indicators studied in the wiregrass were: plants/m² and botanical composition. The CT-115 was measured the number of lateral and basal buds/m², height, yield and cost/t GM and DM produced. The greater number of plants/m² of wiregrass was observed when plowing in June. There was a decrease of 7-8 plants/m² to values lower than 1.7 plants/m² after applying the treatments and planting the CT-115. Similar performance had the percentage of wiregrass which was of 53-68 % before planting CT-115 and decreased to values lower than 7 %. In this treatment, the guinea grass was increased when the plowing started in April and May. The number of basal (30) and lateral (90/m²) buds was larger (P < 0.001) in CT-115 when planted after the plowing in April. The greatest height of CT-115 was obtained in the plowing in April and May (262-272 cm). In the two samplings, the highest yield (9.22-9.49t/ha DM) was reached when the plowing was performed in April. In this treatment, the lowest cost/t DM (4.21 and 14.43 Cuban pesos, respectively) was obtained. It is concluded that the largest biomass production and the lowest (P < 0.01) cost/t GM and DM were achieved when the plowing was performed in April. When using this technology, the wiregrass population is reduced to levels under the critical threshold for this weed in CT-115 grasslands, besides reducing the cost of plantation and establishment. [ABSTRACT FROM AUTHOR]

The article presents a study which examined the effect of different mechanical labors, as well as the chemical and organic fertilization on the control of wiregrass and the recovery of a rangeland of guinea grass likoni. A yield of 3.43 t/ha of guinea grass was attained in the sampling of November when the plowing plus harrowing were applied. The study concluded that the use of mechanical labors like harrowing and chemical fertilization may be a form of recovering rangelands of Panicum maximum and exerting a control of weeds such as Sporobolus indicus.

The article presents a study conducted to assess the effect of the soil preparation and the plantation systems on the control of wiregrass and the CT-115, or Pennisetum purpureum, biomass production. In the treatments with previous soil preparation, the invasion of wiregrass was lower than in the rest, which represented less than 2 percent of the area covered by the weed. It is concluded that the plantation of the CT-115 by the plowing method, with previous conventional soil preparation was an efficient method for the wiregrass control.

A sampling design was used in a grassland of Panicum maximum cv Likoni (Guinea grass), in a calcic ferrallic soil of mid fertility. The area was divided into squares of 625 m to determine the homogeneity and sample size to characterize, from the biological point of view, the species Sporobolus indicus (L.) R. Br. (wiregrass). The variables studied were: DM yield, tuft perimeter and number of plants/m² of wiregrass. Bartlett's test was used for determining the homogeneity of variance between all squares and the squares 1, 3, 5 and 2, 4, 6, respectively. Once the homogeneity test was determined, the sample size was prescribed through the statistical software INFOSTAT (2001). The sample size for the DM yield was of 18, the tuft perimeter, 19, and 16, the number of plants/m², respectively. Thus, an optimum sample of 20 plants was considered for characterizing the biological performance of wiregrass in a Guinea grass ecosystem. [ABSTRACT FROM AUTHOR]

The degradation of swards is produced, in general, together with the loss of the natural fertility of the soils causing the decrease in cattle productivity and great economic losses. It is considered that a sward is degraded when desired species have lost their vigor and productive capacity per unit of area and per animal and unpopulated areas and undesired plants of poor yield and low nutritive value occupy the land surface. This provokes the ecological and economical deterioration, being incompatible with the productive cattle systems. Among the main causes of degradation of swards, there are the indiscriminate use of burning, the invasion of weeds, pests, and diseases, the climatic factors and the poor fertility of the soils. Among the most used techniques for the effective rehabilitation of degraded swards, there is the use of the subsolator, the subsolator doble plowing, plowing + harrowing, plowing + harrowing +organic matter, and plowing + harrowing + complete formula (0.5 t/ha). Out of them, those of the lowest cost-benefit ratio and technical-productive impact have been plowing + harrowing and plowing + harrowing + complete formula. In this study, some reasons were identified supporting the preference for conducting recovery techniques and renewal of degraded swards instead of carrying out new sowings in degraded swards. [ABSTRACT FROM AUTHOR]

Linear mixed and generalized linear mixed models were applied to an experiment with scarified seeds through the process of endozoochory, as tools for processing and analysis with measures repeated over time. Variables analyzed were plant height and stem thickness. Pearson correlation matrix was calculated to determine the existence of association among sampling days. In the analyzed variables, sphericity criterion was used by Bartlett statistic. For both variables, the assumption of normality was verified by Shapiro-Wilk and Kolmogorov-Smirnov tests. In the variable that fulfilled the assumption of normality, a linear mixed model was used. For the variable that was not fulfilled, the generalized linear mixed model was applied. The Poisson, Gamma, Log Normal, Normal and Binomial variants were analyzed to determine data distribution. Several variance-covariance structures were tested to select the best fit and the information criteria that obtained the smallest values were considered. The use of these statistical models allows to adequately control the probability of occurrence of type I error, since it provides greater flexibility and information when selecting the best fit model, in addition to allowing to analyze unbalanced data. [ABSTRACT FROM AUTHOR]

This work had as objective, to evaluate a banana flour, obtained from pulp and shell with a particle size of 140 µ, to produce dairy desserts, in order to profit its functional properties for the populations general feeding and for the infant population particularly. Two different types of dairy dessert were developed: gelled and custard-milk, flavored with coconut and banana respectively. In the development of the gelled dessert two products were obtained: one, where it was totally substituted the native starch used in the original product and another one where it was also substituted part of the present jelly in this product. In the custard-milk all the starch was substituted by banana flour, settling down the formulations of the new products sensorially, by means of descriptive tests of classification, having as criteria the general quality of the products. The appropriate flavors for the desserts were settled down by means of sensorial analysis of profile of flavors where it was established the general quality of the products. The levels of green banana flour utilized were 0.4 and 5% for the gelled milk and the custard-milk, respectively. It was also obtained a gelled milk where a superior level of banana flour was used (0.6%) with reduction of the level of original jelly in 12.5%. The gelled milk of coconut flavor and the custard-milk of banana flavor were qualified as products of good quality. [ABSTRACT FROM AUTHOR]