Agronomic Behavior of Cenchrus purpureus Varieties Tolerant to Salinity

A study was made at the Experimental Station of Pastures and Forages, at the Jorge Dimitrov Agricultural Research Institute to determine the effect of cutting age (60, 90, 120 days), and cultivar (CT-500 and CT-115) of new varieties of Cenchrus purpureus on some yield components . The effects of cutting age (3), cultivar (2), and their interaction (3 x 2), on yields and some agronomic variables were controlled by a randomized block design. Interaction did not to affect the morphological variables of leaves and stems, though it did affect plant height. The cultivars had significant differences (P < 0.001) for the ages of 60 and 90 days; whereas for the number of basal shoots and percent of dry matter in the whole plant, CT-115 was significantly higher at 60 and 120 days, respectively. The total growth rate and biomass duration significantly phased out at 90 days, in favor of CT-500. Both varieties showed potential for high dry matter production per hectare, and only differed (P < 0.001) from the 120 days in the forage areas with saline soils. These results must be considered as preliminary data for the design of a variety structure in saline forage areas

Capacities for Sustainable Production of Beef in Eastern Cuba

Alternatives for calf and cattle fattening were validated, and capacities for beef production in grazing conditions were improved in the eastern part of Cuba. The reproductive behaviors of female Charolais, Creole and Zebu were evaluated for artificial insemination, along with the population data from the cattle fattening units. The herds from those breeds showed higher productivity, especially Charolais, which was higher than the other two. Only thirtysix percent of overall beef production is generated during the fattening stage; 43 % of weight achieved during fattening is produced in the calves, during reproduction. When fattening was started in the late rainy season, or early dry season, the final weights were significantly higher than the starting weights of animals that initiated fattening sometime else in the year. This can be linked to the relative contribution made by the concentrate supplement administered in the first months of fattening, around 30 % of the animal ingestion capacity, with effects on food conversion, and mitigating declines in availability and the quality of pasture in that period. If efficient exploitation capacities are created for these breeds, greater beef yields may be achieved, which will have a positive effect on cattle recovery in Cuba

Comportamiento agronómico de cultivares de Cenchrus purpureus tolerantes a la salinidad

Con el objetivo de determinar el efecto de la edad de corte (60, 90 y 120 días) y del cultivar (CT-500 y CT-115), sobre algunos componentes del rendimiento en nuevas variedades de Cenchrus purpureus, se desarrolló un estudio en la Estación Experimental del Pastos y Forrajes del Instituto de Investigaciones Agropecuarias Jorge Dimitrov. Según diseño de bloques al azar y en arreglo factorial se controlaron los efectos edad de corte (3), el cultivar (2) y su interacción (3 x 2), sobre el rendimiento y algunas variables agronómicas que definen el mismo. Se observó que la interacción no afectó las variables morfológicas de hojas y tallos, pero si la altura de la planta, los cultivares mostraron diferencias significativas (P < 0,001) para las edades de 60 y 90 días, mientras que, para el número de hijos basales y el porcentaje de materia seca en la planta íntegra, el CT-115 fue significativamente superior en las edades de 60 y 120 días, respectivamente. La tasa de crecimiento absoluto y duración de la biomasa se desfasaron significativamente a los 90 días a favor del CT-500. Ambas variedades demostraron el potencial productivo de materia seca por hectárea y solo se diferenciaron (P < 0,001) para la edad de 120 días en condiciones de áreas forrajeras con limitantes de salinidad en el suelo. Se recomienda considerar los resultados del presente estudio como datos preliminares para el diseño de la estructura varietal de áreas forrajeras salinizadas. ABSTRACTTo determine the effect of cutting age (60, 90, 120 days), and cultivar (CT-500 and CT-115) on some yield components in new varieties of Cenchrus purpureus, a study was made at the Experimental Station of Pastures and Forages, at the Jorge Dimitrov Agricultural Research Institute. The effects of cutting age (3), cultivar (2), and their interaction (3 x 2) on yields and some agronomic variables were controlled by a randomized block design. Interaction did not to affect the morphological variables of leaves and stems, though it did affect plant height. The cultivars had significant differences (P < 0.001) for the ages of 60 and 90 days; whereas for the number of basal shoots and percent of dry matter in the whole plant, CT-115 was significantly higher at 60 and 120 days, respectively. The total growth rate and biomass duration significantly phased out at 90 days, toward CT-500. Both varieties showed potential for high dry matter production per hectare, and only differed (P < 0.001) from the 120 days in the forage areas with saline soils. These results must be considered as preliminary data for the design of a variety structure in saline forage areas.

Efecto del ecotipo y la frecuencia de corte en el rendimiento forrajero de Moringa oleifera Lam, en el Valle del Cauto

El estudio se realizó en la Estación Experimental de Pastos y Forrajes, con el objetivo de evaluar el efecto de la frecuencia de corte (45 y 60 días) en el rendimiento forrajero de los ecotipos Nicaragua y Criolla de Moringa oleifera, en condiciones de riego y fertilización orgánica, en un suelo fluvisol del Valle del Cauto. Se utilizó un diseño de bloques al azar con arreglo factorial 2 x 2, con cuatro réplicas. Las plantas se cortaron a 10 cm y se determinaron las variables altura de la planta, cantidad y grosor de brotes, número de hojas, relación hoja/tallo y los rendimientos de materia seca total (MS) y materia seca de hojas y tallos. Excepto la cantidad de brotes, todas las variables analizadas mostraron ser significativas para la frecuencia de corte (P < 0,001), y el número de hojas fue la única variable que mostró diferencia para el factor ecotipo (P < 0,05). Los mayores rendimientos de materia seca total se obtuvieron en la frecuencia de corte cada 60 días con 3,8 t.ha-1 pero debido a la competencia que se creó entre la M. oleifera y gramíneas invasoras, el experimento solo se extendió por 180 días con reducción paulatina de la productividad. Se concluye que la frecuencia de corte cada 60 días mostró mayores rendimientos de MS; sin embargo, la altura de corte empleada favoreció la presencia de plantas invasoras, lo que disminuyó los rendimientos y la sostenibilidad de producción de forrajes del cultivo. ABSTRACT The study took place at the Experimental Station of Pastures and Forages to evaluate the effect of the cutting frequency (45 and 60 days) on forage yields of Moringa oleifera ecotypes Nicaragua and Criolla, with irrigation and organic fertilization, on fluvisol, on the Cauto Valley. A randomized block design with 2x2 factorial design and four replicas was used. The plants were cut 10 cm from the ground, and variables plant height, shoot amount and thickness, number of leaves, leaf/stem ratio, total dry matter (DM) yields, and dry leaves and stems, were determined. Except for the number of shoots, all the variables were significant for the cutting frequency (P < 0.001). The number of leaves was the only variable with a difference for the ecotype factor (P < 0.05). The greatest yields in total dry matter were achieved at 60 days (3.8 t.ha-1). However, the experiment only lasted 180 days with gradual reduction in pro-duction, caused by the competition between M. oleifera and invading graminaceae. The study concluded that the cutting frequency of 60 days produced increased yields of DM. However, the cutting height favored the presence of invading plants, with decreasing yields and sustainability of forage production.