SciELO - Scientific Electronic Library Online

 
vol.8 número3Producción de flores y uso de recursos naturales en Zinacantán, ChiapasPropagación vegetativa de nanche Malpighia mexicana y Byrsonima crassifolia índice de autoresíndice de assuntospesquisa de artigos
Home Pagelista alfabética de periódicos  

Serviços Personalizados

Journal

Artigo

Indicadores

Links relacionados

  • Não possue artigos similaresSimilares em SciELO

Compartilhar


Revista mexicana de ciencias agrícolas

versão impressa ISSN 2007-0934

Rev. Mex. Cienc. Agríc vol.8 no.3 Texcoco Abr./Mai. 2017

https://doi.org/10.29312/remexca.v8i3.34 

Articles

Components of the yield and nutritional value of Brachiaria humidicola cv Chetumal to different grazing strategies

Aldenamar Cruz Hernández1 

Alfonso Hernández Garay2 

Alfonso Juventino Chay Canul1 

Sergio Iban Mendoza Pedroza3 

Santiago Ramírez Vera1 

Adelaido Rafael Rojas García4  §  

Joel Ventura Ríos2 

1División Académica de Ciencias Agropecuarias. Universidad Juárez Autónoma de Tabasco. Carretera Villahermosa-Teapa, km 25. R/A La Huasteca, Tabasco, México. Tel. 01 (993) 3581500, ext. 6604. (ingaldecruz@gmail.com; aljuch@hotmail.com; sarave2@hotmail.com).

2Colegio de Postgraduados-Campus Montecillo. Carretera México-Texcoco, km 36.5. Texcoco, México. CP. 56250. (hernan@colpos.mx; joelventur@gmail.com).

3Departamento de Zootecnia, Universidad Autónoma Chapingo. Carretera México-Texcoco, km 38.5. Chapingo, México. CP. 56230. Tel. (595) 9521500. (simpedroza@hotmail.com).

4Unidad Académica de Medicina Veterinaria y Zootecnia núm.2. Universidad Autónoma de Guerrero. Cuajinicuilapa, Guerrero, México.


Abstract

The objective of this paperwas to study the effect of yield of Brachiaria humidicola cv Chetumal grass at different frequencies and intensities of grazing. The cutoff frequencies of 21 and 28 d and the intensities of 9-11 and 13-15 cm were evaluated, which were randomly distributed in a random block design with 2*2 factorial arrangement with three replicates. Management effects on dry matter accumulation were observed, with accumulation at lower frequency and light grazing intensity being greater. Forage production had a seasonal distribution of 66, 26 and 7% in the rainy season, north and dry seasons, respectively. The leaf ratio in harvested forage was 20, 30 and 86% for north, dry and rainy seasons, respectively. Reductions in dry matter digestibility were observed in the north and rainy seasons as the cut interval increased. The crude protein with severe grazing was 11, 10 and 17% higher in the north, dry and rainy times than with light. It is concluded that the highest forage production was obtained when harvesting at a light intensity of 13-15 cm, every 28 d and the highest protein content and digestibility was obtained when the forage was harvested at severe intensity every 21 d.

Keywords: Brachiaria humidicola; Chetumal grass; forage yield; nutritive quality; pasture frequencies and intensities

Resumen

El objetivo de la investigación fue estudiar el efecto del rendimiento del pasto Brachiaria humidicola cv Chetumal a diferentes frecuencias e intensidades de pastoreo. Se evaluaron las frecuencias de corte de 21 y 28 d y las intensidades de 9-11 y 13-15 cm, que se distribuyeron de forma aleatoria en un diseño de bloques al azar con arreglo factorial 2*2 con tres repeticiones. Se observaron efecto del manejo en la acumulación de materia seca, siendo mayor la acumulación a menor frecuencia e intensidad ligera de pastoreo. La producción del forraje tuvo una distribución estacional del 66, 26 y 7% en épocas de lluvias, nortes y seca, respectivamente. La proporción de hoja en el forraje cosechado fue de 20, 30 y 86% para las épocas de nortes, seca y lluvias, respectivamente. Se registraron reducciones en la digestibilidad de la materia seca en las épocas de nortes y lluvias al aumentar el intervalo de corte. La proteína cruda con pastoreo severo fue 11, 10 y 17% mayor en las épocas de nortes, seca y lluvias que con el ligero. Se concluye que la mayor producción del forraje se obtuvo al cosechar a una intensidad ligera de 13-15 cm, cada 28 d y el mayor contenido de proteína y digestibilidad se obtuvo cuando el forraje se cosecho a intensidad severa cada 21 d.

Palabras claves: Brachiaria humidicola; calidad nutritiva; frecuencias e intensidades de pastoreo; pasto Chetumal; rendimiento de forraje

Introduction

In tropical regions, forages are the main food source for ruminants; however, the environmental conditions and the management of grasslands directly affect the yield and quality of the pastures, so that the nutritive value and production of dry matter is variable during the year. In this regard, seasonality plays an important role in forage production, with a decrease in yield during the dry season, attributed to lack of water and a surplus in the rainy season (Hernández et al., 2002).

For a better forage utilization, it is important to know the timing of harvest from the point of view of the yield, quality and persistence of the plants (Lara and Pedreira 2011; Nantes et al., 2013). These components in the accumulation of forage can be modified by the animal load, which depends on the defoliation degree (Nantes et al., 2013), it has been indicated that with light defoliations in prolonged periods the accumulation of dry matter can decrease; however, with moderate to severe defoliation, the availability of stems photosynthates decreases (Difante et al., 2011).

On the other hand, it has been found that the proportion of leaves in the harvested forage decreases with increasing regrowth age, which is due to greater stem growth, when there are favorable environmental conditions (Hernández et al., 2002; Ramírez et al., 2009). A maturing pasture presents changes in the soluble, structural and digestibility components; under grazing conditions, these changes occur differently and are directly related to the amount and structural components of the residual material after grazing (Inyang et al., 2010). In this regard, Vergara and Araujo (2006), when evaluating two cut frequencies at 14 and 28 days in Brachiaria humidicola, found that increasing the cut frequency decreased the protein content from 8.5 to 6.7%, as well as the digestibility of forage.

The introduction in the tropical region of Brachiaria humidicola cv Chetumal pasture with high forage potential is considered promising within its genus. The importance of using the Chetumal pasture lies in its adaptation to the tropics, since it supports adverse conditions such as prolonged droughts, abrupt topography and poor drainage. In spite of the numerous investigations that are carried out with fodder in Central America and other parts of the world, the information that is generated in the Mexican tropic is scarce, in such a way that the recommendations of how to use the prairies are the same for both native and introduced pastures. The objective of this research was to determine the accumulation of forage and nutritive value of Brachiaria humidicola cv Chetumal pasture at different pasture frequencies and intensities.

Materials and methods

The study was conducted from March 2009 to February 2010 in the experimental area of the Academic Division of Agricultural Sciences of the Autonomous Juárez University of Tabasco (UJAT), located at 17º 46’ 56” north latitude and 92º 57’ 28”west longitude, at 10 masl. In the municipality of Centro, Tabasco, Mexico 25 km from Villahermosa-Teapa road. The climate is of Am (f) (i’) gw type, with rainfall and average annual temperature of 2 010 mm and 27.2 °C, respectively (García, 2004). The precipitation had the following distribution at different times of the year: dry droughts and rains (25, 10 and 65% respectively), where the highest precipitation occurred in September (Figure 1). Precipitation and maximum and minimum temperature data were obtained with the meteorological equipment of the UJAT. The soil corresponds to the luvisol chromic (Palma and Cisneros, 1996).

Figure 1 Distribution of precipitation and average, maximum and minimum monthly temperatures during the period.  

An area of 37.5*48 m was delineated, which was divided into 18 experimental units of 12.5*8 m that were distributed under random block design with three replicates. Sowing of the pasture Brachiaria humidicola cv. Chetumal was manually performed in July 2010, with a distance between woods and furrows of 50 cm and a seed density of 6 kg ha-1 of seeds. Before planting glyphosate herbicide was applied, a concentration of 41% to eliminate present weeds. Fifteen days before the study started a uniform grazing was carried out in all experimental units, two grazing frequencies (FP: 21 and 28 d) and two intensities: severe (9-11 cm) and light (13-15 cm). Ten calves weighing 180 to 230 kg were used per plot only as defoliators, until reaching pasture intensity. The animals remained from 4 to 8 h depending on the time of year.

Fodder yield

In order to evaluate the seasonal and annual forage yield, two fixed quadrants of 50*100 cm were randomly placed on each day before starting the study, which were harvested one day before each grazing at corresponding intensity and frequency. Subsequently, the forage was weighed fresh, placed in paper bags and dried in a forced air oven at 55 °C for 72 h. The dry weight of the forage was recorded and the yield was determined by surface unit (kg MS ha-1).

Morphological components

From fresh forage, a sub-sample of approximately 100 g was taken, which was separated into components: leaf, stem and senescent material which were deposited in labeled paper bags and dried in a forced air oven at 55 °C, for 48 h and weighed on a Scout® Pro digital scale.

Leaf: stem and leaf: not leaf ratio

The leaf: stem and leaf:non leaf ratios were estimated by dividing the yield of the leaf component between stem yield and the sum of stem and senescent material, respectively.

Nutritional value

In order to determine it, at the middle of each season, a sample of approximately 5 kg of fresh fodder was taken, which was washed and dried in a forced air oven at 55 oC for 48 h, and grounded (1 mm diameter mesh). Subsequently, the following determinations were made: protein by the Microkjendhal method (AOAC, 1990). The digestible dry matter content was determined using the nylon bag technique described by Ørskov et al. (1980). Which consisted of taking a sub-sample of 5 g of forage which was deposited in a polysed bag (5*10 cm), bags were grouped and secured with silk thread and then incubated in the rumen in duplicate for 48 h, two Bos taurus*Bos indicus fistulated cattle with a live weight of 300 kg were used. The incubated bags were then removed, washed and fed into a forced air oven at 65 °C for drying.

Statistic analysis

The data were analyzed by a completely randomized block design with factorial arrangement of 2*2 treatments, using the PROC MIXED procedure (SAS, 2009), where the interval effects between cuts, time of year and their interactions were considered as fixed and block effect as random. The multiple comparison of means of treatments was performed using the adjusted Tukey’s test (α= 0.05).

Results and discussion

Fodder yield

The seasonal and annual accumulation of Brachiaria humidicola cv. Chetumal forage subjected to different frequencies and intensities of grazing is shown in Table 1. The frequency of grazing affected forage yield throughout the experimental period (p< 0.01), regardless of the time of year and grazing intensity, as the interval between grazing increased forage yield. The annual yield increased 42% by increasing the interval between grazing from 21 to 28 d (p< 0.05). The rainy season accounted for 66% of the annual forage yield, with 4 298, 5 849 kg DM ha-1 for the frequencies of 21, 28 d respectively and followed by the North and Dry seasons with 26 and 7% annual yield. It was observed that when harvesting with less intensity the annual yield of the forage increased by 16% (p< 0.01) compared to the severe cut.

Table 1 Accumulation of forage by season and annual (kg DM ha-1) of Brachiaria humidicola cv Chetumal pasture, subjected to different frequencies and intensities of grazing. 

Nortes= noviembre-febrero; seca= marzo-mayo; lluvias= junio-octubre; severo= 9-11 cm; ligero= 13-15 cm; ns= no significativo; **= p≤ 0.01; *= p≤ 0.05, abcd= diferente literal minúscula en cada columna, indican diferencia (p< 0.05); EEM= error estándar de la media.

The light harvest exceeded forage yield in 10 and 56% (p< 0.05) to the severe in north and dry, respectively (Table 1). Rainfall and temperature in the rainy season stimulated forage growth and yield. In the northern season, the low temperatures were those that affected the growth of Chetumal pasture, resulting in a lower accumulation as stated by Rojas et al. (2016), obtaining the lowest forage mass in the seasons with lower temperature, independently of the year of study. The response of forage yield to seasonal changes in precipitation and temperature was expected for the hot humid climate conditions of the state of Tabasco. Candide et al. (2006) mention that the greatest growth of forage species occurs between 25 and 35 oC. Other authors mention that good photosynthetic efficiency in tropical pastures occurs when the temperature is within the range of 15 to 45 oC (Sague and Kubein, 2007). The temperature and precipitation data recorded during the study period (Figure 1) show that the limiting factor in forage yield during the dry season was precipitation. In this paper it was observed that increasing the grazing interval increased the accumulation of forage (Table 1).

These results are similar to those obtained by Martínez et al. (2008), who obtained an annual accumulation of 11 583 kg DM ha-1 for this same species when harvested every five and seven weeks. This indicates that, with frequent defoliation, the density of stems in the prairie, which can not intercept 95% of sunlight, is increased because of its higher leaf area index. In contrast, at longer intervals the competition between plants by sunlight increases continuously, so that the grasslands develop a low density of stems but larger and longer leaves (Ramírez et al., 2010). In this regard, Hirata and Pakiding (2004) point out that grasses that undergo frequent grazing and severe intensities decreased forage yield.

Morphological components

The defoliation management of a prairie influences the growth speed, production, botanical composition, quality and its persistence (Nantes et al., 2013). This indicates that it is important to consider not only the forage yield, but also the proportion of leaves in relation to the stems and the senesent material. There was an effect of frequency and intensity of grazing (p< 0.01) in this research, in the leaf component during all seasons of the year. There was no effect of interaction frequency and grazing intensity. The frequency of grazing of 28 d showed 35% more annual leaf yield compared to 21 d (Table 2). The highest accumulation of leaves occurred in the rainy season with 24% in the grazing interval at 28 d compared to 21 d. There were no differences between intensities in the frequency of grazing every 28 d in the leaf component in rainy and dry seasons (p> 0.05). Light grazing presented 20.5, 30.5 and 8.6% higher accumulation of leaves in the North, dry and rainy seasons, respectively, compared to severe grazing (p< 0.05).

Table 2 Accumulation of morphological components by season and annually (kg DM ha-1) of Brachiaria humidicola cv Chetumal, subjected to different frequencies and intensities of grazing. 

Nortes= noviembre-febrero; seca= marzo-mayo; lluvias= junio-octubre; ne = no se encontró; severo= 9-11 cm; ligero= 13-15 cm; ns= no significativo; **= p≤ 0.01; *= p≤ 0.05, abcd= diferente literal minúscula en cada columna, indican diferencia (p< 0.05); EEM= error estándar de la media.

The changes in the morphological composition on the rainy season were due to the edaphic and climatic conditions favoring a greater leaves growth, which is similar with that reported by Festo et al. (2003), who found that leaves increase their appearance when there are temperatures between 20 to 32.5 oC, but decrease if the temperature exceeds 35 oC. Regarding to the northern period, the changes were due to the fact that the growth of the plants was inhibited by the low temperatures, whereas in the dry season the water stress allowed little growth consisting mainly of leaves. The frequency of grazing had an effect on the accumulation of stems (p< 0.01) in the north and rainy season; while the intensity and interaction frequency by grazing intentions only had an effect in the rainy season (Table 2).

The highest accumulation of stems was obtained in the rainy season 76% more in the 28 d interval compared to 21 d; followed by the northern period. While with light grazing the accumulation of stems was 13.5 and 25% higher compared to severe grazing for periods of north and rainy, respectively. These results are similar to those reported by Ramírez et al. (2009), who mention that the proportion of leaves in the harvested forage decreases as the interval between harvests increases, due to a higher growth of the stem, when the environmental conditions are favorable for plants growth as it happens in the time of rainfall; on the contrary, during the norths season the stem elongation is inhibited by the low temperatures, and in the dry season the water deficit (Sage and Kubein, 2007) limits the growth of the plants and, consequently, the contribution of the stem to forage yield is zero.

The higher accumulation of forage in the grazing interval of 28 day compared to that of 21 day coincided with the greater number of leaves and stems. This behavior was observed by Ramírez et al. (2009); Difante et al. (2011); Hernández et al. (2002); Calzada et al. (2014); Rueda et al. (2016) who affirm that the plant’s age determines the distribution of dry matter in its different morphological components.

Leaf:stem and leaf:non leaf ratio

In general, Chetumal grass has an excellent leaf: stem ratio (Table 3). There was an effect of frequency and grazing intensity, as well as interaction, during the rainy season (p< 0.05). The leaf-stem ratio during the rainy season was 27% higher (p< 0.05) when grazing every 21 day, which decreased as the interval between grazing increased, although climatic conditions were favorable for the grass growth, during rainy season the leaf: stem ratio was due mainly to the management, as demonstrated by Ramírez et al. (2009), when increasing the cutting age of 3 to 7 weeks there was found a lower leaf: stem ratio in Mombaza grass (Panicum maximum Jacq.).

Table 3 Seasonal changes in leaf: stem and leaf: non-leaf ratio of Brachiaria humidicola cv Chetumal, by time of year, subjected to different frequencies and intensities of grazing. 

Nortes= noviembre-febrero; seca= marzo-mayo; lluvias= junio-octubre; &= 100% hojas; severo= 9-11 cm; ligero= 13-15 cm; ns= no significativo; **= p≤ 0.01; *= p≤ 0.05; abc= diferente literal minúscula en cada columna, indican diferencia (p< 0.05); EEM= error estándar de la media.

The intensity of grazing had an effect (p< 0.01) on the leaf: stem ratio during the rainy season (Table 3), and it was observed that severe grazing was greater in 6% in rains and 1% in north compared to light grazing. Regarding the leaf: non-leaf ratio, frequency and intensity effects, as well as interaction frequency x intensity (p< 0.05) were shown in the rainy season. The higher values in the leaf: stem ratio were associated with the sampling technique, since the harvested forage was performed at predetermined grazing heights, which avoided harvesting a larger number of stems, which are located close to the surface ground. In addition, when considering the stoloniferous growth habit of the Chetumal grass, the high leaf-stem ratio and the absence of senescent material are explained since it was concentrated in the lower strata of the prairie.

Nutritional value

The frequency and intensity of grazing had a significant effect on crude protein content (p< 0.05) only in the rainy season where the content of the Brachiaria humidicola grass protein was observed to decrease by 20% with increasing grazing frequency 21 a 28 day. A similar behavior was observed during the period of norths and dry (Table 4).

Table 4 Dry digestible matter and crude protein content of Brachiaria humidicola cv Chetumal, by time of year, subjected to different frequencies and intensities of grazing. 

Nortes= noviembre-febrero; seca= marzo-mayo; lluvias= junio-octubre; DIGMS= materia seca digestible; severo= 9-11 cm; ligero= 13-15 cm; ns= no significativo; *= p≤ 0.05; ab= diferente literal minúscula en cada columna, indican diferencia (p< 0.05); EEM= error estándar de la media.

In general, crude protein with severe grazing was 10, 9, and 15% higher in seasons of norths, dry and rainfall, respectively, compared to light grazing. It has been pointed out that the environment and the management in terms of frequency and intensity of grazing are the main factors affecting the yield, quality and persistence of a prairie cultivated with grasses (Hernández et al., 2002). Thus, when a pasture is frequently grazed and at a severe intensity the forage production is lower but with higher digestibility (Ramírez et al., 2009), since the greatest amount of harvested forage are leaves.

In this research it was observed that increasing the interval between grazing decreased the crude protein content and digestibility of the dry matter of Chetumal pasture, this behavior is due to the fact that in a plant, the older the plant the thicker the cell wall gets, best known as fiber. The highest protein content during the dry season was attributed to the low leaf growth, where the highest amount of nutrients were found.

It was observed that the amount of crude protein was higher in the ages of smaller regrowths that result with more frequent cuts. This behavior has been observed by other researchers who mention that the nutritive quality of forages is closely linked to their maturity and environmental conditions at the time of harvesting (Lara and Pedreira, 2011). In this regard, Cano et al. (2004), found that the concentration of crude protein decreases with increasing age of cuts. In this regard, Vergara and Araujo (2006) report for Brachiara humidicola that increasing the cutting interval from 14 to 28 d during the rainy season decreased crude protein content from 8.5 to 6.7%, but increased NDF content of 72.54 to 77% and ADF of 43.2 to 41%.

Conclusions

The forage potential of Brachiaria humidicola cv Chetumal was influenced by the time of the year, with greater regrowth and yield in the rainy season. The highest accumulation of forage was obtained when grazing at a light intensity of 13-15 cm in height every 28 d and with the severe intensity of 9-11 cm the digestible dry matter and the crude protein content was higher. It is recommended to continue with this type of research spending more time on it and with that to broaden the landscape in the decisions management of a Brachiaria humidicola prairie.

Literatura citada

AOAC (Association of Official Analytical Chemists). 1990. Official Methods of Analysis. 15 (Ed). Washington, D. C. USA. 12 p. [ Links ]

Cano, C. C. P.; Cecato, U.; Canto, M. W.; Rodrígues, A. B.; Jobim, C. C.; Rodrígues, A. M.; Galbeiro, S.; e Nascimento, W. G. 2004. Produção de forragem do Capim Tanzânia (Panicum maximum Jacq. cv. Tanzânia) pastejado em diferentes alturas. Rev. Bras. Zootec. 33(6):1949-1958. [ Links ]

Calzada, M. J. M.; Enríquez, Q. J. F.; Hernández, G. A.; Ortega, J. E. y Mendoza, P. S. I. 2014. Análisis de crecimiento del pasto maralfalfa (Pennisetum sp.) en clima cálido subhúmedo. Rev. Mex. Cienc. Pec. 5(2):247-260. [ Links ]

Cândido, D. M. J.; Silva, G. R.; Neiva, M. J. N.; Facó, O.; Benevides, I. Y. e Farias, F. S. 2006. Fluxo de biomassa em capim-tanzânia pastejado por ovinos sob três períodos de descanso. Rev. Bras. Zootec. 35(6):2234-2242. [ Links ]

Difante, G. S.; Júnior, D. N.; Da Silva, S. C.; Euclides, V. P. B.; Montagner, D. B.; Silveira, M. C. T.; e Pena, K. D. 2011. Características morfogênicas e estruturais do capim-marandu submetido a combinações de alturas e intervalos de corte. Rev. Bras. Zootec. 40(5):955-963. [ Links ]

Festo, J. M.; Sabed, N. A.; e Jeremy, A. R. 2003. The impact of temperature on leaf appearance in bamba groundnut landraces. Crop Sc. 43:1375-1379. [ Links ]

García, E. 2004. Modificaciones al sistema de clasificación climática de Koppen. 4ta (Ed.). UNAM. México, D. F. 217 p. [ Links ]

Hernández, G. A.; Martínez, H. P. A.; Mena, U. M.; Pérez, P. J. y Enríquez, Q. J. F. 2002. Dinámica del rebrote en pasto insurgente (Brachiaria brizantha Hochst. stapf.) pastoreado a diferente asignación en la estación de lluvia. Téc. Pec. Méx. 40(2):193-205. [ Links ]

Hirata, M. and Pakiding, W. 2004. Tiller dynamics in Bahia grass (Paspalum notatum): an analysis of responses to nitrogen fertilizer rate, defoliation intensity and season. Tropical Grassland. 38:100-111. [ Links ]

Inyang, U.; Vendramini, M. B.; Sollenberger, B. L.; Adesogan, L. A. and Lupha, A. 2010. Forage species and stocking rate effects on animal performance and herbage responses of ‘Mulato’ and Bahiagrass pasture. J. Crop Sci. 50:1079-1085. [ Links ]

Lara, S. M. A.; e Pedreira, P. C. G. 2011. Respostas morfogênicas e estruturais de dosséis de espécies de Braquiária à intensidade de desfolhação. Pesquisa Agropec. Bras. 46(7):760-767. [ Links ]

Martínez, M. D.; Hernández, G. A.; Enríquez, Q. J. F.; Pérez, P. J.; González, M. S. S. y Herrera, H. J. G. 2008. Producción de forraje y componentes del rendimiento del pasto Brachiaria humidicola CIAT 6133 con diferente manejo de la defoliación. Téc. Pec. Méx. 46(4):427-438. [ Links ]

Nantes, N. N.; Euclides, V. P. B.; Montagner, D. B.; Lempp, B.; Barbosa, R. A.; e Gois, P. O. 2013. Desempenho animal e características de pastos de capim‐piatã submetidos a diferentes intensidades de pastejo. Pes. Agropec. Bras. 48(1):114-121. [ Links ]

Ørskov, E. R.; DeB, H. F. D. and Mould, F. 1980. The use of nylon bag technique for the evaluation of feedstuffs. Tropical Animal Production. 5(3):195-213. [ Links ]

Palma, L. D. J. y Cisneros D. J. D. J. 1996. Plan de uso sustentable de los suelos de Tabasco. Vol. I. Fundación Produce Tabasco, A. C. Villahermosa, Tabasco. 116 p. [ Links ]

Ramírez, R. O.; Hernández, G. A.; Carneiro, D. S.; Pérez, P. J.; Enríquez, Q. J. F.; Quero, C. A. R.; Herrera, H. J. G. y Cervantes, N. A. 2009. Acumulación de forraje, crecimiento y características estructurales del pasto Mombaza cosechado a diferentes intervalos de corte. Téc. Pec. Méx. 47(2):203-213. [ Links ]

Ramírez, R. O.; Hernández, G. A.; Carneiro, D. S.; Pérez, P. J.; de Souza, J. S. J.; Castro, R. R. y Enríquez, Q. J. F. 2010. Características morfogénicas y su influencia en el rendimiento del pasto Mombaza, cosechado a diferentes intervalos de corte. Trop. Sub. Agroec. 12: 303-311. [ Links ]

Rojas, G. A. R.; Hernández, G. A.; Quero, C. A. R.; Guerrero, R. J. D.; Ayala, W.; Zaragoza, R. J. L. y Trejo, L. C. 2016. Persistencia de Dactylis glomerata L. solo y asociado con Lolium perenne L. y Trifolium repens L. Rev. Mex. Cienc. Agríc. 7(4):885-895. [ Links ]

Rueda, J. A.; Ortega, J. E.; Hernández, G. A.; Enríquez, Q. J. F.; Guerrero, R. J. D. and Quero, C. A. R. 2016. Growth, yield, fiber content and lodging resistance in eight varieties of Cenchrus purpureus Morrone intended as energy crop. Bio. Bioen. 88:59-65. [ Links ]

Sage, F. R. and Kubein, S. D. 2007. The temperature response of C3 and C4 photosynthesis. Plant Cell and Enviroment. 30:1086-1106. [ Links ]

SAS, Institute. 2009. SAS/STAT® 9.2. Use’s Guide Release. SAS Institute Inc. Cary, NC, USA. 360 p. [ Links ]

Vergara, L. J. y Araujo, F. O. 2006. Producción, composición química y degradabilidad ruminal in situ de B. humidicola (Rendle) Schweick en el bosque seco tropical. Revista Científica FCV-LUZ. 16(3):239-248. [ Links ]

Received: February 2017; Accepted: April 2017

Creative Commons License Este es un artículo publicado en acceso abierto bajo una licencia Creative Commons